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71M6541 Demo Board User`s Manual

1. COMBO FQOTPRINT Positive Supply 100uF 15V Svp P n wer Down Circui I ds Pa IC ai p Note C29 C32 and C34 have been reversed owe Circuit 0 22uF 4N4148WS bs 2 Ech on the silk screen This schematic is NEUTRAL IN C8 Q2 3 correct 275V R18 BC857 D15 Jean R7 1N4148WS 2M x BOARD SUPPLY BA H gt SEGDIOS D7 D13 D14 1N4148WS 1N4148WS 1N4148WS c29 R6 S1J E3 p 1000uF 6V 8 20K 64 0805 0 1uF R27 130 4 K V PS Y R14 J a Q3 Q4 1 Under Normal Conditions SEGDIO8 is high and 80000 BCX70 M indicates presence of power 20K C13 e OAK C26 R19 2 Under NEUTRAL Cut Conditions SEGDIO8 is low and M current is greater than 1 Amp d ki 4 7 4 3 Under Power Down Conditions VA IN down SEGDIO8 LINE iNatagw8 100uF 15V 1N4148wWB 100uF 15V 1N4148WB 150 Shunt Regulator v is low and surfen jisrero JP6 Negative Supply 3 Negative Supply 2 Negative Supply 1 29r PSP V3P3SYS 1 a LINE i Lit Off Page Connectors Ferrite Bee 600ohm 058 100pF p lt D9 141 e UGLAMP3301D R66 R64 R47 R39 Ferrite Bead 6000hm 9 Vapasys NEUTRAL IN S l NYA A VA gt gt va 100 NG 2M
2. 35 Figure 2 4 Single Phase Three Wire Meter with two Shunt Sensors 36 Figure 2 4 Watt Meter with Gain and Phase Emors 37 Figure 2 5 Phase Angle Definitions e esses sseseeeee eene nennen theme AA 40 Figure 2 7 Calibration Spreadsheet for Three Measurements 43 Figure 2 8 Calibration Spreadsheet for Five Measurements nennen nennen neret 44 Figure 2 9 Non Linearity Caused by Quantification Noise 45 Figure 2 10 GAIN ADJ over Temperature einen nennen entren innen 49 Figure 2 11 GAIN ADJ and GAIN ADJ over Temperature enne nnnnemrn nsn nnn nhnnntr nns n nnn n naan AKNG 49 Figure 2 12 Meter with Calibration System 52 Figure 2 13 Galibr tion System SCreen eio demi HORE HN OM REGNO 52 Figure 2 14 Wh Load Lines at Room Temperature with 71M6201 and
3. Figure 2 16 Improved Sensor Arrangement 55 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 2 6 4 OTHER TECHNIQUES FOR AVOIDING MAGNETIC CROSSTALK With very high currents or close distances between shunt sensors magnetic pickup or cross talk will sometimes occur even if good placement practices are followed One mechanism for cross talk is shown in Figure 2 17 where the Manganin zone and the sensor wire act as a loop that will generate an output voltage similar to that generated by a Rogowski coil The effect of this loop can be compensated by adding a second loop on the opposite side of the shunt resistors as shown in Figure 2 18 Optional contact for voltage rr Sensor wires Copper Loop E Figure 2 17 Loop Formed by Shunt and Sensor Wire Manganin Symmetrical Figure 2 18 Shunt with Compensation Loop Since the compensation loop is impractical a similar compensation effect can be achieved by attaching the sensor wires in the center as shown in Figure 2 19 An economical approach to this technique is to drill holes in the center of the shunt resistor for attachment of the sensor wires o 11 E O O Figure 2 19 Shunt with Center Drill Holes Patent pending 56 Rev 4 0 57 71M6541 Demo Board REV 3 0 User s Manual Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 3 HARDWARE DESCRIPTION 3 1 71M6541 DB DESCRIPTION JUMPERS SWI
4. nana 34 2 1 1 Sensor ln EE 34 2 1 2 Single phase two wire EQU 0 nns 35 2 1 3 Single phase three wire EQU 1 36 2 2 Calibration Theory aaa aaa 37 2 2 1 Calibration with Three Measurements 37 2 2 2 Calibration with Five Measurements nnne AEn saa tnnt nennen nnns 38 2 3 Calibration Procedures aie See k sion ann kn n out e ANAN aaa 2 3 1 Calibration Equipment 2 3 2 Phase bysPhase Galibration EE 40 2 3 3 Detailed Calibration Proce Tt eoi ettet ei e De REPRE AA n 40 2 3 4 Calibration Procedure with Three Measurements 41 71M6541 Demo Board REV 3 0 User s Manual 2 3 5 Calibration Procedure with Five Measurements nnns 42 23 6 Galibrati r Spreadsrieets re dee don ee ig n Ree Por pr np ee ena 42 2 3 7 Gompensatirig for Non Linearities la mete mene etes et pale ence oe cepi ecd gine tee 45 2 4 Temperature COMPENSATION LA
5. 71M6541 Signal Direction Function ICE E Input to the 71M6541 ICE interface is enabled when ICE E is pulled high E TCLK Output from 71M6541 Data clock E RXTX Bi directional Data input output E RST Bi directional Flash Downloader Reset active low Table 1 5 Flash Programming Interface Signals a The E_RST signal should only be driven by the Flash Downloader when enabling these interface S signals The Flash Downloader must release E_RST at all other times 22 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 1 10DEMO CODE 1 10 1 DEMO CODE DESCRIPTION The Demo Board is shipped preloaded with Demo Code in the 71M6541F chip The code revision can easily be verified by entering the command si via the serial interface see section 1 8 1 Check with your local Maxim In tegrated representative or FAE for the latest revision The Demo Code is provided in two different versions e Single phase two wire operation EQU 0 with secondary tamper sensor Energy measurement and Wh VARh pulses are based solely on VA phase A voltage and IA phase A current Energy and cur rent values for IB secondary phase are available as CE outputs to the MPU for processing of tamper ing events e Single phase three wire operation ANSI configuration EQU 1 Energy measurements and Wh VARh pulses are based on VA IA IB 2 Both Demo Code versions use the same CE code but with different settings of the EQU register
6. EENS ee 7 1 7 1 Powert Supply Setup aani Lima Kab BA Dap te tu EE eii pagba 8 1 7 2 Cables for Serial Communication 8 M78 Checking Operations fed seat Eee tb Ma ae ee tebe ll BA red erant gn ain 9 AZA Seral Connection SOU DEE 9 1 8 Using the D mo Board 10 1 8 1 Serial Command Language AA URN RR REM T T 11 1 8 2 Using the Demo Board for Energy Measurements nennen nnne 17 1 8 3 Adjusting the Kh Factor for the Demo Board 17 1 8 4 Adjusting the Demo Boards to Different SHUNT Resistors 17 1 8 5 Using the Pre Amplifler ee edhe ee Voye e ke Pov e ente 17 1 8 6 Using Current Transformers CTS 17 1 8 7 Implementing a Single Phase 3 Wire Meter EQU 1 17 1 8 8 Adjusting the Demo Boards to Different Voltage Dividers 17 1 9 Calibration Parameters Za a aNG 18 1 9 1 General Calibration Procedhure AAA 18 1 9 2 Hee Mei lee dE 19 1 9 3 Updatin
7. 31 Table 1 10 Identification of 71 M6XOX Remote Sensor 065 32 Table 2 1 Temperature Related Error Sources 46 Table 2 2 Temperature Related Error Sources 50 Table 3 1 71M6541 DB 1 3 0 1065611 011011 BANA NANA Aa 60 Table 4 1 71M6541 DB REV 3 0 Bill of Material ene nnnnn nene nnrennnene nnne nenn nnne 67 Table 4 3 71M6541 Pin Description Table 1 3 nennen ener 73 Table 4 4 71M6541 Pin Description Table 2 3 nnn ennt nnnn nennen nnns 738 Table 4 5 71M6541 Pin Description Table 3 8 nrimaa nennen nennen nnne AA 74 4 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 1 GETTING STARTED 1 1 GENERAL The Maxim Integrated 71M6541 DB REV 3 0 Demo Board is a demonstration board for evaluating the 71M6541 device for single phase electronic energy metering applications in conjunction with the Remote Sensor Inter face It incorporates a 71M6541 inte
8. enne beroia mank aranana ssi ani tn ssi sse anna 62 4 idu Pe 64 4 1 71M6541 DB Electrical Schematic eeeeeeeeeeeeeeee sees AA 65 4 2 71M6541 DB Bill of Material iii aasa NAA 67 4 3 71M6541 DB PCB LayOUt aNg kk a ABA aaa 69 AA 71M6541 Pinout Information AA 73 4 5 Revision History E E 76 List of Figures Figure 1 1 06541 REV2 0 Demo Board with Debug Board Basic Connections 7 Figure 1 2 HyperTerminal Sample Window with Disconnect Button Arrow 10 Figure 1 3 Port Speed and Handshake Setup left and Port Bit setup 11011 10 Figure 1 4 Typical Calibration Macro File 19 Figure 1 5 Emulator Window Showing Reset and Erase Buttons see Arrows 21 Figure 1 6 Emulator Window Showing Erased Flash Memory and File Load Menu 21 Figure 2 1 Shunt CONNECTIONS eee ke eie RU REPERIO ERR EAR ERRARE 34 Figure 2 2 Single Phase Two Wire Meter with Shunt Sensor 35 Figure 2 3 Single Phase Two Wire Meter with two Shunt Sensors
9. Ba optonal gg VBALRIO 121 bog PTO lipo rm _ eno sz olo 77 RTM INTERFACE E TF RESET Si LJ z J12 Jess RESET TMUXOUT Blot poro E VBAT d ohneci 6 TMUX2OUT 6 JoHo T OPT Battery 1 VRSI 4 lol optional V5 DBG 3 l On board components 15 16 V5 NI lt s 5V DC j O owered by V3P3D a y o 414 GNDDBG IL k a e los 621 Monte IN 06 03 2010 USB V Interface gt CN1 Isolator Serial USB K Converter GND Figure 1 1 71M6541 DB REV3 0 Demo Board with optional Debug Board Basic Connections The Demo Board contains all circuits necessary for operation as a meter including display calibration LEDs and internal power supply Communication with a PC USB port is provided via connector CN1 The optional Debug Board uses a separate power supply and is optically isolated from the Demo Board It interfaces to a PC through the USB connector It is recommended to set up the demo board with no live AC voltage connected and to connect live AC voltages only after the user is familiar with the demo system Sg All input signals are referenced to the VIP3A 3 3V power supply to the chip 7 Rev 4 0 1 7 1 1 7 2 71M6541 Demo Board REV 3 0 User s Manual POWER SUPPLY SETUP There are several choices for the meter power supply o Internal using the AC line voltage The internal power supply is only suitable when the voltage ex ceeds 100V RMS To e
10. MINVC 5 VC is below VThrshld Voltage for this phase is in creep CREEPV 6 All voltages are below VThrshld CREEP 7 There is no combination of current and voltage on any phase SOFTWARE 8 A software defect was detected error software was called For example An impossible value occurred in a selection or the timers ran out NEUTRAL 9 Neutral current was above in limit for more than in wait seconds SPURIOUS 10 An unexpected interrupt was detected SAG 11 Voltage was below VThrshld for more than in wait seconds DEMAND 12 Demand was too big too many watts to be credible CALIBRATION 13 Set after reset if the read of the calibration data has a bad checksum or is from an earlier ver sion of software The default values should be present RTC UNSET 14 Set when the clock s current reading is A Obtained after a cold start indicating that there was no battery power and therefore the clock has to be invalid B More than a year after the previ ously saved reading or C Earlier than the previously saved reading In this case the clock s time is preserved but the clock can t be trusted HARDWARE 15 An impossible hardware condition was detected For example the software times out waiting for RTC RD to become zero BATTERY BAD 16 Just after midnight the demo code sets this bit if VBat VBatMin The read is infrequent to reduce battery loading to very low values When the battery voltage is being displayed the read occur
11. The shunt connected here should be the one correspond ing to the neutral side of the meter 29 JP2 5 pin header for access to OPT TX and OPT RX signals 30 JP3 ICE E 3 pin header for the control of the ICE E signal A jumper across pins 1 2 disables the ICE interface a jumper across pins 2 3 enables it 31 JP7 SEGDIO51 2 pin header that allows connecting the 59 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual SEGDIO51 OPT TX pin to the LCD If the second UART is used the jumper should be removed from the header 2x10 emulator connector port for the Signum ICE ADM 51 or for the TFP2 Flash Programmer Three 2 pin headers that connects the E RXTX E RXTX 33 JP54 E RXTX and E TCLK pins to the LCD The emulator pins should be configured as LCD pins when this jumper is inserted 32 J14 EMULATOR I F 2 pin header that allows connecting the 34 JP8 SEGDIO55 SEGDIO51 OPT_RX pin to the LCD If the second UART is used the jumper should be removed from the header 35 J19 SPI 2X5 header providing access to the SPI slave interface Four 2 pin headers that connect the SPI DI SPI DO JP9 JP10 SELA SPI CK and SPI CSZ pins to the LCD The SPI pins 36 SPI CK d JP11 JP12 should be configured as LCD pins when these jumpers are SPI CSZ inserted This connector is an isolated USB port for serial communi zi ES Hep PORT cation wit
12. 6 04 10 TRIMT and TCo 8 11 107 4 19 10 TRIMT The TRIMT value can be read from the 71M6X0X Remote Sensor Interface IC The reference voltage of the 71M6541 IC At the temperature extremes this voltage can deviate by a few mV from the room temperature voltage and can therefore contribute to some temperature related error both for the current measurement pins IAP and IAN of the secondary shunt sensor and for the voltage measurement pin VA As with the Remote Sensor Interface IC the TC of the 71M6541 re ference voltage has both linear and quadratic components The reference voltage of the 71M6541 over temperature is predictable within 40 PPM C which means that compensation of the current and voltage reading is possible to within 0 24 The temperature coefficients of the reference voltage are published in the IC data sheet The voltage divider network resistor ladder on the Demo Board will also have a TC Ideally all resis tors of this network are of the same type so that temperature deviations are balanced out However even in the best circumstances there will be a residual TC from these components The error sources for a meter are summed up in Table 2 1 Table 2 1 Temperature Related Error Sources Measured Item Error Sources for Current Error Sources for Voltage Energy reading in direct channel 71M6541 VREF 71M6541 VREF VA and IAP IAN Shunt resistor at IAP IAN Voltage divider for VA 46 VA and IBP IB
13. NANA 5V O 1uF Ko aa JP5 RX USB 2 VCCIO AGND veus CG D USB Ferrite Bead 6000hfn en 1 2192 UART RX ISO 3 RO NG 22 Uses D 3 D_USB c3 Ce 1000pH GND 29554 Rit 8050 771 D CG SS FS HDR2X1 SES FT232RQ 98051 20 x ris SEND 0 01uF out 4 7uF R4 sws x SEED TMUX2OUT 27 DSR vec Hi S R2 JGND USB Wi se U 4 RESET TMUXOUT DCD RESET 57 O 0 7 X cts a55 ND 400 B106 ff SDa Bag a USB Interface soot LK 4 Off Page Connectors 28890888 a our x x 4 va sEGDIO8 ba R9 C55 ERES 77 711 6541 Demo Board REV SS HDR8X2 NE TT ope VaPsA Ddvapasys M C33 1M6541 Demo Boar 3 0 3 V Debug Connector Rit 62 gt iap gt 1an IBP DIN 5 Pie Document Number Hawa Se Ola 5 di Orup Date Monday Ma E y 09 2011 Bheet 2 of 2 66 Figure 4 2 71M6541 DB REV 3 0 Demo Board Electrical Schematic 2 2 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 4 2 71M6541 DB BILL OF MATERIAL Table 4 1 71M6541 DB REV 3 0 Bill of Material Item Q Reference Part Footprint DigKeyP N Mouser P N Manufacturer ManufacturerP N Tol Rating HDR DNP M NOU 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 67 w m Uu 16 N QU P n 696 to H N 23 11 RRR ta 511 812 5813 CN1 C1 C2 C3 C7 C27 C4 C18 C19 C20 C21 C22 C28 C3
14. Model 2300 LOOP MODE Task Hyper Sequence vi Test As As Service Upper Loy Step Type Found Left Revs Ele Volt Amp Type Limit Lit Lookup Code E 1 03 410 5 s 2400 30 00 Wye ABC 375 Form 15 lE _Defauts Wl 32 voltage 240 Amp 30 Test Seg 172 Rev Tase vi 1 AFLimis 1 AF Limit ALLimis 2 AL mt Service we ABC yi Reverse Power IV Start Delay 3 Optics maer 0 1 Turtle Option va vb Me la 16 16 Pa Pb Pc Pab Pac Revs Freq we Blees ees ee X X X X X X I I Ier Test Complete Figure 2 13 Calibration System Screen 52 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Form 25 Wh Error 96 at 0 60 and 300 Phase Angle 240 V 60 Hz 0 25 0 20 0 15 0 10 0 05 0 00 0 05 0 10 H 300 0 15 uL me 0 20 0 25 0 1 1 10 100 1000 Figure 2 14 Wh Load Lines at Room Temperature with 71M6201 and 50 pQ Shunts 2 6 SENSORS AND SENSOR PLACEMENT 2 6 1 53 Both sensor self heating and sensor placement has to be considered in order to avoid side effects that can af fect measurement accuracy These considerations apply in general to both ANSI meters and IEC meters Both meter variations will be discussed below SELF HEATING The effect of self heating will be most pronounced at maximum current and depends on the following parame ters e Nominal shunt resistance e Current through the shunt resis
15. SEGDIO20 C315 SEGDIO19 C316 338 2 OPT TX SEGDIO51 SEGDIO4 427 SEGD SEGD SEGD SEGD SEGD SEGDIOS8 DI C23 SEGDIO5 126 SEGDIO3 SDATA T428 SEGDIO7 YPULSE 124 SEGDIO2 SDCK T429 SEGDIO6 XPULSE C425 SEGDIO1 VPULSE C30 SEGDIOO WPULSE 431 OPT RX SEGDIO55 432 Figure 4 7 71M6541 LQFP64 Pinout Top View 75 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 4 5 REVISION HISTORY REVISION DATE DESCRIPTION 2 0 1 14 2010 Initial release based on DBUM revision 1 1 for 6541 REV 1 0 Demo Board Added Table 1 8 and explanation of scaling in CE and MPU codes Added cau 2 1 1 16 2010 tionary notes for connection of Line and Neutral Updated formulae for WRATE and kh calculation Updated Figures 2 1 2 2 and 2 3 Updated CLI tables and Bill of Material 22 1 29 2010 Added chapter on temperature compensation Removed most text referencing CTs and added notes stating that different Demo Code versions will be required for a CT configuration Updated Demo Kit contents list Updated Table 1 9 Added chapters on shunt os 2516 2010 self heating and shunt placement 24 3 5 2010 Corrected description of IMAX calculation Added more information on self heating Added description of test and control commands for 71M6X0X Remote Sensor 2 5 6 3 2010 Updated Demo Board schematics Updated Demo Board top level diagram Fig ure 1 1 Added Figure 2 1 showing proper shunt connectio
16. b bytes combinations FSabc xyz Write characters to buffer sets Write length FTa Transmit buffer to Flash memory at address a FWa b z Write string of bytes to buffer Example FShello Writes hello to buffer then transmits buffer to EEPROM start FT FE10 ing at address OxFE10 12 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 13 Auxiliary Commands un Typing a comma repeats the command issued from the previous command line This is very helpful when examining the value at a certain address over time such as the CE DRAM address for the temperature 0x40 The slash is useful to separate comments from commands when sending macro text files via the serial in terface All characters in a line after the slash are ignored Commands controlling the CE TMUX and the RTM Description Allows the user to enable and configure the compute engine store and recall configurations and initiate calibration Usage C option argument Command CEn Compute Engine Enable 1 gt Enable combinations 02 Disable CTn m Selects the signal for the TMUX output pins n 1 for TMUXOUT n 2 for TMUX2OUT m is interpreted as a dec imal number CREn RTM output control 1 Enable 0 Disable CRSa b c d Selects CE addresses for RTM output CLS Stores calibration and other settings to EEPROM CLR Restores calibration and other settings from EEPROM CLD Rest
17. currents in each phase Each phase can still be individually calibrated using the following sequence e When calibrating phase A the calibration coefficient for the current in phase B is set to zero This way the pulses are generated solely based on phase A The kH factor of the calibration system must be ad justed by 50 to account for the suppression of 50 of the energy e When calibrating phase B the calibration coefficient for the current in phase A is set to zero This way the pulses are generated solely based on phase B The kH factor of the calibration system must be ad justed by 50 to account for the suppression of 50 of the energy e Forthe final step both current calibration coefficients are set to their calibration values and the meter can be tested at the original kH setting 2 3 3 DETAILED CALIBRATION PROCEDURES 40 The procedures below show how to calibrate a meter phase with either three or five measurements The PHADJ equations apply only when a current transformer is used for the phase in question Note that positive load angles correspond to lagging current see Figure 2 6 D d a oS Voltage 7 RD Bs 7 i N i a Current lags N i voltage i inducti Positive i ia direction 460 5 A L EE 1 umen Ud NEE Current leads voltage N i capacitive J SCH bl J 1 7 SC i T 7 Papang a p Voltage a 1 3 Generating Energy Using Energy Figure
18. gles to confirm the desired accuracy Store the new calibration factors CAL_In CAL_Vn and PHADJ_n in the EEPROM or FLASH memory of the meter If the calibration is performed on a Maxim Integrated Demo Board the methods involving the command line interface as shown in sections 1 9 3 and 1 9 4 can be used Repeat the steps 1 through 7 for each phase For added temperature compensation read the value TEMP_RAW CE RAM and write it to TEMP_NOM CE RAM If Demo Code 4 6n or later is used this will automatically calculate the cor rection coefficients PPMC and PPMC2 from the nominal temperature and from the characterization da ta contained in the on chip fuses Tip Step 2 and the energy measurement at 0 of step 3 can be combined into one step Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 2 3 5 CALIBRATION PROCEDURE WITH FIVE MEASUREMENTS Each phase is calibrated individually The calibration procedure is as follows 1 2 The calibration factors for all phases are reset to their default values i e CAL In CAL Vn 16384 and PHADJ n 0 An RMS voltage Vigea consistent with the meter s nominal voltage is applied and the RMS reading Vactual Of the meter is recorded The voltage reading error Axv is determined as Axv Vactual Videal Videal Apply the nominal load current at phase angles 0 60 180 and 60 300 Measure the Wh ener gy each time and record the errors Eo Ego E180 and Eao
19. 50 WO Shunt 53 Figure 2 15 Typical Sensor Arrangement left Recommended Arrangement right 55 Figure 2 16 Improved Sensor Arrangement 55 Figure 2 17 Loop Formed by Shunt and Sensor Wire nnns 56 Figure 2 18 Shunt with Compensation Loop tnnee rnit n nnns 56 71M6541 Demo Board REV 3 0 User s Manual Figure 2 19 Shunt with Center Drill Holes nnns 56 Figure 3 1 71M6541 DB REV 3 0 Board Description enne eene 61 Figure 4 1 71M6541 DB REV 3 0 Demo Board Electrical Schematic 1 2 65 Figure 4 2 71M6541 DB REV 3 0 Demo Board Electrical Schematic 2 2 66 Figure 4 3 71M6541 DB REV 3 0 Top EE 69 Figure 4 4 71M6541 DB REV 3 0 Top Copper nnns 70 Figure 4 5 71M6541 DB REV 3 0 Bottom View nennen nnne nnne nennen nnne nennen nnn
20. Gain and Phase Errors During the calibration phase we measure errors and then introduce correction factors to nullify their effect With three unknowns to determine we must make at least three measurements If we make more measurements we can average the results and get better accuracy CALIBRATION WITH THREE MEASUREMENTS The simplest calibration method is to make three measurements Typically a voltage measurement and two Watt hour Wh measurements are made A voltage display can be obtained for test purposes via the command gt MR2 1 in the serial interface Let s say the voltage measurement has the error Ey and the two Wh measurements have errors Ep and Ego where Eo is measured with A 0 and Eso is measured with dh 60 These values should be simple ratios not percentage values They should be zero when the meter is accurate and negative when the meter runs slow The fundamental frequency is fo T is equal to 1 fs where fs is the sample frequency 2560 62Hz Set all cali bration factors to nominal CAL IA 16384 CAL VA 16384 PHADJA 0 Note In the formulae used in this section the register variable name PHADJA is used The CE code for the 71M6541 in reality uses a more advanced type of compensation that results in a delay adjust The register name for this compensation factor is DLYADJ A For the purpose of the calculation the two names are interchangeable From the voltage measurement we determine that 1 35 A E 41
21. LINEARITIES 45 Nonlinearity is most noticeable at low currents as shown in Figure 2 9 and can result from input noise and truncation Nonlinearities can be eliminated using the QUANT variable Bro IW A oo o 5 6 a pe o A IW o o Figure 2 9 Non Linearity Caused by Quantification Noise The error can be seen as the presence of a virtual constant noise current While 10mA hardly contribute any er ror at currents of 10A and above the noise becomes dominant at small currents The value to be used for QUANT can be determined by the following formula error V 100 VMAX IMAX LSB Where error observed error at a given voltage V and current I VMAX voltage scaling factor as described in section 1 8 3 IMAX current scaling factor as described in section 1 8 3 LSB QUANT LSB value 7 4162 10 W QUANT Note that different values for the LSB of QUANT apply depending on which type of code is used The LSB val ues are listed in the IC data sheet for standard CE codes Example Assuming an observed error for a meter with local sensors as in Figure 2 9 we determine the error at 1A to be 0 5 If VMAX is 600V and IMAX 208A and if the measurement was taken at 240V we determine QUANT as follows QUANT LSB 1 04173 10 VMAX IMAX 1 3 107 QUANT 100 9230 QUANT _ LSB QUANT is to be written to the CE location given by the IC data s
22. The Demo Code offers the following features e lt provides basic metering functions such as pulse generation display of accumulated energy fre quency date time and enables the user to evaluate the parameters of the metering IC such as accu racy harmonic performance etc e t maintains and provides access to basic household functions such as the real time clock RTC e lt provides access to control and display functions via the serial interface enabling the user to view and modify a variety of meter parameters such as Kh calibration coefficients temperature compensa tion etc e It provides libraries for access of low level IC functions to serve as building blocks for code de velopment A detailed description of the Demo Code can be found in the Software User s Guide SUG In addition the comments contained in the library provided with the Demo Kit can serve as useful documentation The Software User s Guide contains the following information e Design guide e Design reference for routines e Tool Installation Guide e List of library functions e 80515 MPU Reference hardware instruction set memory registers 1 10 2 IMPORTANT MPU ADDRESSES In the demo code certain MPU XRAM parameters have been given addresses in order to permit easy external access These variables can be read via the command line interface if available with the n command and written with the nzxx command where n is the word address Note that accu
23. The records from 0x00000 to 0x00400 are ignored so that the bootloader can t overwrite itself If the bootloader load process is not invoked the bootloader jumps to address 0x0400 and executes the code found there A detailed description of the bootloader can be found in the readme txt file contained in the source code ZIP package a 71M6541 DB containing code with the bootloader instructions for loading new code are as follows Connect a PC running HyperTerminal or a similar terminal program to the DB6543 Set the program to 38 400 baud 8 bits no parity XON XOFF flow control Turn off the power to the 71M6541 DB Install a jumper from board ground to the VARh pulse output JP59 right pin which is also SEGDIO1 A low voltage on this pin signals to the bootloader that new code should be loaded via the UART Apply power to the meter After a brief delay the Wh pulse LED D5 will light up SEGDIOO The bootloader should send a on the UART to the PC If this occurs the flash is erased and the 71M6541 DB is ready to load code If this does not occur check the jumper and reset or repower the unit If the Wh LED still does not light up then the boot code is not installed If the Wh LED lights up but the does not appear debug the RS 232 wiring Possible issues are that the baud rate is not 38400 baud or that the wiring is wrong debug using a known good meter or that the terminal program in the PC is not workin
24. current measurements SEGDIO559 7G 14F 14E DP0 2C 2B 48 SEGDI010 i E COM2 IBN SEGDIO710 78 143 140 X4 3E 3F 7 SEGDIOTI 1 2 disabled C57 C31 C30 R15 62 COM3 7 coms GNDD 42 JP53 SEGDIO710 TAMAA 14G 3D 3G 3A 47 SEGDIO11 2 3 enabled 1000pF R16 62 COME 8 71M6541 41 V3P3D BAN 1 pup 2 V3P3D SEGDIO414 714 3G 3A 46 SEGDIOT2 22pH 22pR R17 62 COM5 9 SEGDIO27 COM4 V3P3D 40 Vap5 SEGDI0222 DP7 14B DP14 DP3 3C 3B 45 SEGDIO13 gi SEGDIO25 10 SEGDIO26 COMS VDD Ce ICE E HDR2X1 SEGD10513 8F 15F 15E X3 4E 4F 44 SEGDI014 1 k u EE SEGDIO24 11 SEGDIO25 ICE E 38 E RXIX R7 C28 SEGDIO914 8E 15G 15D 4D 4G 4A 43 SEGDIO19 2 SEGDIO23 12 SEGDIO24 SEG48 E RXTX 37 E TCLK 0 1uF SEGDIO195 8D 15A 15C DP4 4C 4B 42 SEGDIO20 3 SEGDIO22 13 SEGDIO23 SEG49 E_TCLK 36 E RST SEGDIO116 8C 15B DP15 X2 5E 5F 44 SEGDIO21 prey c49 pads SEGDIO21 14 SEGDIO22 SEG50 E RST 35 UART RX T SEGDIOIg 8 16 165 50 5G 5A 25 SEGDIOZA 1000pF 1K SEGDIO20 15 SEGDIO21 ww RX 34 UART TX 1000pF SEGDIO138 88 16G 16D DP5 5C 5B 39 SEGDIO25 SEGDIOTS 16 SEGDIO20 ERE pe OPT TX SEGDIOi4 8A 16A 16C X1 6E 6F 35 SEGDIO4A D SEGDIO19 EE S SEGDI051 0P7 Tx H3 PE T SEGDIOT20 DP8 18B DP16 6D 6G 6A 22 SEGDIO45 Kaz GOLEG T AUF m SEGDIO201 9F 17F 17E DP6 6C 6B 36 SEGDIOSG Noe touro 8 202255 R BEGDIO242 9E 17G 17D 10D 10G 10A 32 SEGDIOS7 lote Remove Se Oe EIER SEGDIO 222 35 SEGDI037 JP60 J
25. jumper on JP1 when using D1 Note Remove Jumpers Before Using X Y Pulse Leet di R5 ower downugircuit c A V3P3SYS XPULSE SEGDIO6 YPULSE SEGDIO7 V3P3D PULSE OUTPUTS SEGDIOS H D5 Wh R74 100K pana S V3P3SYS 1 P 2 4 WPULSE V3P3SYS n V3P3A DNP J12 Ve lt 7 10K SS SSC SSL LX5093SRC E AR 022 C52 C51 San VBAT x ES ofa ofa JP58 1000pF 10uF 0 1uF 1000pF O tuF 10uF pal V3P3SYS mn mu 4 4 4 4 4 TMUXOUT WV HDR2X1 JP44 JP45 TOUT D6 VARh R76 br S N3P3SYS 1 D 2 4 VPULSE Note Batteries not populated
26. measured in VARh per VARISUM X 1 55124 10 IMAX VMAX accumulation interval The sum of squared current samples in element 1 IA This value is I0SQSUM X 2 55872 10 IMAX VMAX the basis for the lous calculation performed in the MPU The sum of squared current samples in element 2 IB This value is TISOSUM X 2 5587 10 IMAX VMAX the basis for the lous calculation performed in the MPU VOSQSUM X 9 40448 10 IMAX VMAX The sum of squared voltage samples in element 1 VA The sum of squared voltage samples in element 1 VA This value is VISQSUM X 9 40448 10 IMAX VMAX not used for EQU 0 or EQU 1 1 10 4 CALCULATING IMAX AND KH The relationship between the resistance of the shunt resistors and the system variable IMAX is determined by the type of Remote Sensor Interface used and is as follows IMAX 0 044194 Rs for the 71M6601 IMAX z 0 012627 Rs for the 71M6201 Where Rs Shunt resistance in Q Table 1 9 shows IMAX values resulting from possible combinations of the shunt resistance value and the type of 71M6X0X Remote Sensor Interface used for the application All values are for PRE E 0 I O RAM register 2704 0x90 PULSE FAST 0 and PULSE SLOW 0 The CE register at address 0x30 has to be adjusted as shown in the rightmost column of the table 30 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Table 1 9 IMAX for Various Shunt Resistance Values and Remote Sensor Types R
27. methods because they work with most manual calibration systems based on counting pulses emitted by LEDs on the meter Naturally a meter in mass production will be equipped with special calibration code offering capabilities beyond those of the 71M6541 Demo Code It is basically possible to calibrate using voltage and current readings with or without pulses involved For this purpose the MPU Demo Code can be modified to display averaged voltage and current values as opposed to momentary values Also automated calibration equipment can communi cate with the Demo Boards via the serial interface and extract voltage and current readings This is possible even with the unmodified Demo Code Complete calibration procedures are given in section 2 3 of this manual Regardless of the calibration procedure used parameters calibration factors will result that will have to be ap plied to the 71 M6541F chip in order to make the chip apply the modified gains and phase shifts necessary for accurate operation Table 1 4 shows the names of the calibration factors their function and their location in the CE RAM Again the command line interface can be used to store the calibration factors in their respective CE RAM ad dresses For example the command gt 10 16302 stores the decimal value 16302 in the CE RAM location controlling the gain of the current channel CAL IA The command gt 11 4005 stores the hexadecimal value 0x4005 decimal 1
28. minimize the effects of self heating Rev 4 0 2 6 2 54 71M6541 Demo Board REV 3 0 User s Manual The effect of shunt self heating can be described by the following formulae First the relative output of a shunt resistor is AVN AR R AR is a function of the change in temperature the temperature coefficient the thermal resistance and of course the applied power which is proportional to the square of the current AV AR R AT TC V R R Ultimately it is up to the meter designer to select the best combination of shunt resistance TC shunt geometry and potential software algorithms for the given application PLACEMENT OF SENSORS ANSI The arrangement of the current terminals in an ANSI meter enclosure predetermines shunt orientation but it al so allows for ample space in between the sensors which helps to minimize cross talk between phases PR Ru TC A good practice is to shape the shunts like blades and to place them upright so their surfaces are parallel In a 16S meter the distance between the phase A sensor and the phase B sensor is roughly 1 which makes these two phases most critical for cross talk For the form 2S meter which is a very frequently used single phase con figuration the distance between the sensors is in the range of 2 75 which makes this configuration much less critical However even for this case good sensor placement is essential to avoid cross talk Sensor wires should be tight
29. of temperature dependence Before we do that we must consider that the equations for temperature compensation are struc tured in a special way i e e If an error source affects both current and voltage measurements the original PPMC and PPMC coeffi cients are used e If an error source affects only one measurement the original PPMC and PPMC2 coefficients are divided by 2 Following this procedure we obtain the coefficients for GAIN ADJA as follows e PPMC PPMCyg2 PPMC4y PPMCyp 2 3331 2 820 788 2 2092 e PPMC2 PPMC2 PPMC24x 680 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual For the control of GAIN ADJB we will need the following coefficients Cs2 Since we assume that the shunt resistors are very similar with respect to their TC we use the val ue found for the shunt connected at phase B PPMC 3331 Again PPMC2s for the shunt resistor is 0 Since this coefficient applies to the current measurement only we will have to apply the Ve factor mentioned above Cax PPMC yy 820 and PPMC2 y 680 as already stated above Since these coefficients apply to the voltage measurement only we will have to apply the factor mentioned above Cex PPM C 960 and PPMC2 y 610 Since these coefficients apply to the current measurement only we will have to apply the factor of 72 that was mentioned above Cvp The PPMCyp value of 788 determined for the voltage divider We obtain the coefficients for G
30. pin is used to reset the chip into a known state RESET For normal operation this pin is pulled low To reset the chip this pin should be pulled high This pin has an internal 30 pA nominal current source pulldown No external reset circuitry is necessary RX UART input If this pin is unused it must be terminated to V3P3D or GNDD TX O UART output TEST Enables Production Test l This pin must be grounded in normal operation PB Push button input This pin must be at GNDD when not active or unused A rising edge sets the E PB flag It also causes the part to wake up if it is in SLP or LCD mode PB does not have an internal pullup or pulldown resistor Pin types P Power O Output Input I O Input Output 74 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 35 A W Zo OYODE 4402 TOO YO Onaxxu au It TOO S28 Ota EE Hoon EC SSSLSSFOX SE E tO NT OO ON oO iO st OD DN e QO O O O O LO LO LO LO tO 1 IN D io st SPI DI SEGDIO38 SPI DO SEGDI037 12 SPI CSZ SEGDIOS36 13 46 31 VBAT D Ka UJ gt 5 JJ 4 O COMO C34 45 V3P3SYS COM1 45 44 Ea IBP COM2 C6 43 3 IBN COM3 C37 ibid ducc d 423 GNDD SEGDIO27 COM4 C38 71 M6541 D 41 2 V3P3D SEGDIO26 COM5 T19 SEGDIO25 410 71 M6541 F 39 KI ICE E SEGDIO24 C11 SEGDIO23 412 37E3E TCLK SEG49 SEGDIO22 413 36 _1 E RST SEG50 SEGDIO21 C314 35 J RX
31. pins VA and V3P3A on the IC 22 J3 IAN IN IAP IN 2 pin header for the connection of the primary non isolated shunt This header is on the bottom of the board Since the board is at line voltage the shunt corresponding to the line side of the meter should be connected here Caution Connecting the shunt corresponding to the neutral voltage will result in board damage 23 JP6 A jumper is placed across JP6 to activate the internal AC power supply Caution High Voltage Do not touch 24 J11 NEUTRAL The NEUTRAL voltage input connected to V3P3 This input is a spade terminal mounted on the bottom of the board 25 J4 LINE LINE is the line voltage input to the board It has a resistor divider that leads to the pin on the IC associated with the voltage input to the ADC This input is a spade terminal mounted on the bottom of the board Caution High Voltage Do not touch this pin 26 J10 IBP IBN 2 pin header connected to pins IBP and IBN on the IC 27 28 J8 J5 IBP IN IBN IN 2 pin header on the bottom of the board for optional con nection of a CT When using a CT the burden resistor lo cations R33 R34 have to be populated Also the resistors and capacitors for filtering R26 C25 R57 C12 and for biasing the IBP IBN inputs R86 R87 must be populated 2 pin header for the connection of the secondary remote shunt This header is on the bottom of the board
32. to the limited number of avail able display digits Internal registers counters of the Demo Code are 64 bits wide and do not wrap around 4 1 Momentary power in W P phase 8 19 88 88 88 88 88 88 N o S Rev 4 0 1 8 2 1 8 3 1 8 4 1 8 5 1 8 6 1 8 7 1 8 8 71M6541 Demo Board REV 3 0 User s Manual USING THE DEMO BOARD FOR ENERGY MEASUREMENTS The 71M6541 Demo Board was designed for use with shunt resistors connected directly to the IAP IAN pins of the 71M6541 and via the Remote Sensor Interface and it is shipped in this configuration The Demo Board may immediately be used with a 50 Q shunt resistor ANSI or a 120 uQ shunt resistor IEC It is programmed for a kh factor of 1 0 see Section 1 8 4 for adjusting the Demo Board for shunts with different resistance Once voltage is applied and load current is flowing the red LED D5 will flash each time an energy sum of 1 0 Wh is collected The LCD display will show the accumulated energy in Wh when set to display mode 3 com mand M3 via the serial interface Similarly the red LED D6 will flash each time an energy sum of 1 0 VARh is collected The LCD display will show the accumulated energy in VARh when set to display mode 5 command gt M5 via the serial interface ADJUSTING THE KH FACTOR FOR THE DEMO BOARD The 71M6541F Demo Board is shipped with a pre programmed scaling factor Kh of 1 0 i e 1 0 Wh per pulse In order to be used with a c
33. with Notepad or an equivalent ASCII editor program The file is executed with HyperTerminal s Transfer gt Send Text File command disable CE CAL_IA gain CAL_IA 16384 CAL VA gain CAL VA 16384 PHADJ A default 0 enable CE Figure 1 4 Typical Calibration Macro File It is possible to send the calibration macro file to the 71M6541F for temporary calibration This will temporarily change the CE data values Upon power up these values are refreshed back to the default values stored in flash memory Thus until the flash memory is updated the macro file must be loaded each time the part is powered up The macro file is run by sending it with the transfer gt send text file procedure of HyperTerminal NG SO Use the Transfer 3 Send Text File command UPDATING THE DEMO CODE HEX FILE The d merge program updates the hex file usually named 6541 1p2b 19jan09 hex or similar with the values contained in the macro file This program is executed from a DOS command line window Executing the d merge program with no arguments will display the syntax description To merge macro txt and old 6541 demo hex into new 6541 demo hex use the command d merge old 6541 demo hex macro txt new 6541 demo hex The new hex file can be written to the 71M6541F 71M6544H through the ICE port using the ADM 51 in circuit emulator or the TFP 2 flash programmer Rev 4 0 1 9 4 1 9 5 20 71M6541 Demo Board REV 3 0 User s Manual UP
34. 2 6 Phase Angle Definitions Rev 4 0 2 3 4 41 71M6541 Demo Board REV 3 0 User s Manual The calibration procedures described below should be followed after interfacing the voltage and current sensors to the 71M6541F chip When properly interfaced the V3P3 power supply is connected to the meter neutral and is the DC reference for each input Each voltage and current waveform as seen by the 71M6544F is scaled to be less than 250mV peak CALIBRATION PROCEDURE WITH THREE MEASUREMENTS Each phase is calibrated individually The calibration procedure is as follows 1 2 The calibration factors for all phases are reset to their default values i e CAL In CAL Vn 16384 and PHADJ n 0 An RMS voltage Vigea consistent with the meter s nominal voltage is applied and the RMS reading Vactual Of the meter is recorded The voltage reading error Axv is determined as Axv Vactual Videal 7 Videal Apply the nominal load current at phase angles 0 and 60 measure the Wh energy and record the er rors Eo AND Ego Calculate the new calibration factors CAL_In CAL_Vn and PHADJ_n using the formulae presented in section 2 2 1 or using the spreadsheet presented in section 2 3 6 Apply the new calibration factors CAL_In CAL_Vn and PHADJ_n to the meter The memory loca tions for these factors are given in section 1 9 1 Test the meter at nominal current and if desired at lower and higher currents and various phase an
35. 2 y PHADJ CAL Jun Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 2 3 CALIBRATION PROCEDURES 2 3 1 CALIBRATION EQUIPMENT Calibration requires that a calibration system is used i e equipment that applies accurate voltage load current and load angle to the unit being calibrated while measuring the response from the unit being calibrated in a re peatable way By repeatable we mean that the calibration system is synchronized to the meter being calibrated Best results are achieved when the first pulse from the meter opens the measurement window of the calibration System This mode of operation is opposed to a calibrator that opens the measurement window at random time and that therefore may or may not catch certain pulses emitted by the meter It is essential for a valid meter calibration to have the voltage stabilized a few seconds be SW fore the current is applied This enables the Demo Code to initialize the 71M6541F and to KTA stabilize the PLLs and filters in the CE This method of operation is consistent with meter u applications in the field as well as with metering standards During calibration of any phase a stable mains voltage has to be present on phase A This uS enables the CE processing mechanism of the 71M6541F necessary to obtain a stable cali bration 2 3 2 PHASE BY PHASE CALIBRATION Each meter phase must be calibrated individually Some calibration systems do not allow selective control of
36. 270K 270K 4 7K 113 R32 B RV1 ba 0805 0805 0805 750 2 H VARISTOR 805 bg 192 gt gt SEGDIO8 1 al 1000pF 3634 4 3 VaP3A LINE J4 Ferrite Bead 600oh Ferrite Bead 6000hm A 040 056 O 1 v nnn 470uF 0 1uF L14 T616 L8 K Sa 1000pF R23 N Ferrite Bead 1800hm 750 ANANA a JAP gt gt 1AP L2 R84 10K 2 R24 2 R25 bo 014 C15 34 534 V3P3A gt gt IBN 1206 1206 C67 1000pF 100pF DNP DNP R85 O 1uF P P IA 29186 10K GEN o l L3 1000pF Shunt Connection WW 4 4 1 JAN PES Ferrite Bead 1800hm TESTPOINTIP3 R56 0 Ba VIS 750 750 11 0056 x DN R a IBN 5 4 6 25 35 LOAD Ferrite Bead 600ohm R22 1K TMUX GND Ti Ferrite Bead 6000hm jg R86 1000pF 1000pF NP INP 6 INP SN 3 SN 1 4 4 INN NN 10K DNP DNP J10 217 DNP La 0 al ey INN 7 inn sp 2 SP 195 R34 R33 V3P3A 1 il 2d 3 3 4 3 4 cea io 1000pF 8 1 2 3 a aaa 1206 1206 ok NZ i l TEST voc Ferrite Bead 6000hm R87 L7 10K C12 C37 1B C23 ci1 For Optional CT DNP 1000pF 1000pF 71M6601 0 471F ptiong faut Default oner DNP DNP Ferrite Bead 6000hm R55 1000pF 1 i d Be INEEN 1 GND R6000 1 J T n R89 d 11116 i 71M6541 Demo Board REV 3 0 Ji Ferrite Bead 6000hm 1K Isolated Sensor and signal transformer 1 NA NEUTRAL IN Bize Document Number ev l B D6541 3 0 NEUTRAL L12 Date Tuesday May 10 2011 Eheet 1 of 2 65 Figure 4 1 71M6541 DB REV 3 0 Demo Board Electrical Schematic 1 2 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Remove
37. 3 C51 C56 C60 C62 C64 C67 C68 C5 C6 C8 C9 C10 C14 C16 C17 C23 C24 C36 C43 C49 C50 C52 C57 C61 C63 C97 C11 C12 C25 C35 C37 C13 C26 C32 C15 C55 C58 C29 C30 C31 C34 C40 C45 C47 DI D2 D3 D4 D7 D10 D11 D13 D14 D15 D5 D6 D8 D9 JP1 JP3 JP44 JP45 JP2 TP1 J3 JP5 J5 JP6 J6 JP7 J7 JP8 J8 JP9 JP10 J10 JP11 JP12 J12 J13 JP53 JP54 JP55 JP57 JP58 JP59 JP20 J4 11 J14 J19 J21 L1 L4 L5 L6 L7 L8 L11 L12 L13 L14 L16 12 13 o Q3 04 RV1 R1 R88 R89 R2 R3 R4 R5 BATTERY BATTERY USB B 15pF 10pF 0 1uF 0 1uF 0 01uF 4 7uF 0 22uF 1000pF 0 47uF 1000pF 100uF 15V 100pF 1000uF 6V 22pF 33uF 6 3V 470uF 10uF BAS21 S1J E3 1N4148WS SSL LX5093SRC E LED UCLAMP3301D HDR3X1 HDR5X1 HDR2X1 SWITCHCRAFT Spade Terminal ICE Header HDR5X2 HDR8X2 BAT 3 PIN BARREL COMBO BAT CR2032 MAX USBV 603 603 805 603 603 805 Block 603 603 603 CAP P833 ND 603 CAP P5115 ND 603 SIZE 3216 CAP CYL D 400 LS 200 034 SM CT 3216 SOT 23 AC SMA DIODE LED6513 805 SOD 323 BLKCON 100 V H TM1SQ W 1 00 3 BLKCON 100 V H TM1SQ W 1 00 5 BLKCON 100 V H TM1SQ W 1 00 2 SWITCHCRAFT Faston RIBBON65130 UTLINE BLKCON 100 V H TM20E W 2 00 10 BLKCON 100 V H TM20E W 2 00 16 Ferrite Bead 600ol 805 HI2220R181R Ferrite Bead 18001 d BC857 BCX70 VARISTOR 1K 0 0 100 100K SOT 23 BCE SOT 23 BCE MOV C
38. 31 mm 5 276 x 5 157 1 6mm 0 062 40 mm 1 57 40 85 C 40 C 100 C 100 V 240 V RMS 5 0 VDC 0 3 V lt 10 mA typical 0 240 V RMS 0 27 8 mV peak for Remote Sensor Input 0 31 5 mV peak for direct input IAP IAN 2 5 mm circular Switchcraft RAPC712X 10x2 header 0 05 pitch Spade terminals on PCB bottom 0 1 1X2 headers on PCB bottom USB connector 8x2 header 0 1 pitch 5x2 header 0 1 pitch 64 KB FLASH memory 1Mbit serial EEPROM 32 768kHz 20PPM at 25 C Push button SW5 Push button SW3 3X8 digit LCD 7 segments per digit plus meter symbols red LED D5 red LED D6 120 600 V rms resistor division ratio 1 3 398 Dependent on shunt resistance or CT ratio burden resis tor Rev 4 0 63 71M6541 Demo Board REV 3 0 User s Manual Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 4 APPENDIX This appendix includes the following documentation tables and drawings 71M6541 Demo Board Description D6541 REV 3 0 Demo Board Electrical Schematic D6541 REV 3 0 Demo Board Bill of Materials D6541 REV 3 0 Demo Board PCB layers copper silkscreen top and bottom side 71M6541 IC Description 71M6541 Pin Description 71M6541 Pinout 64 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 4 4 71M6541 DB ELECTRICAL SCHEMATIC
39. 6389 in the CE RAM location controlling the gain of the volt age channel CAL_VA The internal power supply generates a ripple on the supply and ground nets that is 90 phase shifted with re spect to the AC supply voltage This affects the accuracy of the VARh measurements If optimization of the VARh accuracy is required this can be done by writing a value into the QUANT_VAR register of the CE see section 2 3 7 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Table 1 4 CE RAM Locations for Calibration Constants Coefficient res Description Adjusts the gain of the voltage channels 16384 is the typical value The gain is directly proportional to the CAL parameter Allowed range is 0 to 32767 If the gain is 1 slow CAL should be increased by 1 Adjusts the gain of the current channels 16384 is the typical value The gain is directly proportional to the CAL parameter Allowed range is 0 to 32767 If the gain is 1 slow CAL should be increased by 1 PHADJ_A This constant controls the phase compensation No compensation occurs LCOMP2_B in a phase when PHADJ A 0 or when LCOMP2_n 16384 As LCOMP2 n is increased more compensation is introduced CE codes for CT configuration do not use delay adjustment These codes use phase adjustment PHADJ_n 1 9 2 CALIBRATION MACRO FILE 1 9 3 19 The macro file in Figure 1 4 contains a sequence of the serial interface commands It is a simple text file and can be created
40. 7 21UGC TR8 UCLAMP3301D TCT PBC36SAAN PBC36SAAN PBC36SAAN RAPC712X 62395 1 5 104068 1 PBC36DAAN PBC36DAAN MMZ2012S601A HI2220R181R 10 BC857CE6327 BCX70KE6327XT 2381 594 55116 CRCWO08051K00JNEA MCRI8EZHJOOO CRCWO06030000Z0EA CRCWO08051K00JNEA ERJ 3GEYJ104V 5 5 10 10 10 10 10 20 X596 2096 1596 2096 2096 10 5 5 5 5 DNP DNP 50V 50V 50 275 100 50 100 16 100 6 3 50 DNP 6 3V 10V 10V 0 1 0 2 0 1 0 2 0 3 5A Rev 4 0 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 68 NNUNP BU RH B UB EB UU m np ta R6 R7 R66 R8 R106 R142 R9 R10 R11 R12 R13 R14 R15 R16 R17 R18 R19 R20 R21 R22 R26 R55 R57 R23 R32 R56 R24 R25 R33 R34 R27 R39 R47 R64 R74 R76 R103 R104 R105 R84 R85 R86 R87 R141 SW3 SW5 TP2 TP3 TI u1 U2 U3 U4 US 08 015 YI 8 20K 2M 1K 62 100K 20K 6 04K 62 30K 150 8 06K 25 2K 750 3 4 130 4 7K 270K 10K 10K 10K 100 PB TESTPOINT TESTPOINT 750 11 0056 TL431 FT232RQ ADUM3201 SER EEPROM 71M6541 LCD VLS 6648 71M6601 32 768KHz 805 AXLE FLAME UPRIGHT 603 603 603 805 805 603 805 805 805 805 805 805 1206 1206 805 805 603 805 805 AXL
41. AIN ADJB as follows e PPMC3 PPMCyg2 PPMC4y2 PPMCsxl2 PPMCyp 2 3331 2 820 2 960 2 788 2 2162 e PPMC2 PPMC22g2 PPMC24x 2 PPMCay2 O 680 2 610 2 985 2 5 TESTING THE DEMO BOARD This section will explain how the 71M6541F IC and the peripherals can be tested Hints given in this section will help evaluating the features of the Demo Board and understanding the IC and its peripherals Demo Board It interfaces to a PC through a 9 pin serial port connector It is recommended to set up the demo board with no live AC voltage connected and to e connect live AC voltages only after the user is familiar with the demo system BEFORE CONNECTING THE DEMO BOARD TO A CALIBRATION SYSTEM OR OTHER HIGH VOLTAGE SOURCE IT IS RECOMMENDED TO MEASURE THE RESISTANCE BE TWEEN THE LINE AND THE NEUTRAL TERMINALS OF THE DEMO BOARD WITH A MULTI METER ANY RESISTANCE BELOW THE 1 MO RANGE INDICATES A AFAULTY CONNEC TION RESULTING INDESTRUCTION OF THE 71M6541 2 5 1 FUNCTIONAL METER TEST This is the test that every Demo Board has to pass before being integrated into a Demo Kit Before going into the functional meter test the Demo Board has already passed a series of bench top tests but the functional meter test is the first test that applies realistic high voltages and current signals from current transformers to the Demo Board Figure 2 12 shows a meter connected to a typical calibration system The calibrator supplies calibrated
42. AL VA 16384 PHADJA 0 First calculate Axy from Ev 1 3 Ay E 1 Calculate Ax from Eo and 180 _ IV Ay Ay cos 0 9 2 E IV cos 0 1 Ay Ay cos 9 1 IV Ay Ay cos 180 IV cos 180 4 E Een 2Ayy Ag c08 0 2 3 Eiso 1 Ayy Ay cos l Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Pi BE P2 2C08 P _ E Eiso 2 1 Ayy cos Use above results along with Ego and E300 to calculate bs _ IV Ayy Ax cos 60 9s E IV cos 60 Ay Ay COS Ayy Ay tan 60 sin 1 5 A A 623 Ay 7 60 IV Ay Ay cos 60 9 8 Eso IV cos 60 Ay Ay cos Ayy Ay tan 60 sin 1 Subtract 8 from 7 9 Eg Ex 2Ay Ay tan 60 sin use equation 5 E E 2 101 E E tan 60 sin cos gs 11 Es Epp Ey Ej 2 tan 60 tan 1253 dan Es Fw tan 60 Ey Ey 2 Now that we know the Ayy Ax and bs errors we calculate the new calibration voltage gain coefficient from the previous ones CAL V CAL Vyn XV We calculate PHADJ from 05 the desired phase lag tan g 9 14 1 27 2 2 1 2 cos 27f T 1 2 sin2zf T tan 9 2 cos 2af T And we calculate the new calibration current gain coefficient including compensation for a slight gain increase in the phase calibration circuit CAL I 1 Ay m 2 PHADJ 242 PHADJ 2 1 2 cos 27f T 1 20 2 cosQaf T 0
43. AT RTC to VIP3SYS Analog Pins Table 4 3 71M6541 Pin Description Table 2 3 Name Type Description IAP IAN Differential or single ended Line Current Sense Inputs These pins are volt IBP IBN age inputs to the internal A D converter Typically they are connected to the outputs of current sensors Unused pins must be tied to V3P3A Pins IBP IBN may be configured for communication with the remote sensor interface 71M6X0X VA Line Voltage Sense Input This pin is a voltage input to the internal A D con verter Typically it is connected to the output of a resistor divider Unused pins must be tied to V3P3A Voltage Reference for the ADC This pin should be left unconnected float VREF O ing XIN Crystal Inputs A 32 kHz crystal should be connected across these pins Typi XOUT O cally a 15 pF capacitor is also connected from XIN to GNDA and a 10 pF capacitor is connected from XOUT to GNDA It is important to minimize the capacitance between these pins See the crystal manufacturer datasheet for details If an external clock is used a 150 mV p p clock signal should be applied to XIN and XOUT should be left unconnected Pin types P Power O Output Input I O Input Output 73 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Digital Pins Table 4 4 71M6541 Pin Description Table 3 3 Name Type Description COM3 C
44. DATING CALIBRATION DATA IN FLASH OR EEPROM It is possible to make data permanent that had been entered temporarily into the CE RAM The transfer to EEPROM memory is done using the following serial interface command gt CLS Thus after transferring calibration data with manual serial interface commands or with a macro file all that has to be done is invoking the U command Similarly calibration data can be restored to default values using the CLD command After reset calibration data is copied from the EEPROM if present Otherwise calibration data is copied from the flash memory Writing OxFF into the first few bytes of the EEPROM S deactivates any calibration data previously stored to the EEPROM LOADING THE CODE FOR THE 71M6541 INTO THE DEMO BOARD Hardware Interface for Programming The 71M6541F IC provides an interface for loading code into the inter nal flash memory This interface consists of the following signals E_RXTX data E_TCLK clock E_RST reset ICE_E ICE enable These signals along with V3P3D and GND are available on the emulator headers J14 Programming of the flash memory requires a specific in circuit emulator the ADM 51 by Signum Systems www signum com or the Flash Programmer TFP2 available through Digi Key www digikey com or Mouser Electronics www mouser com Chips may also be programmed before they are soldered to the board Gang programmers suitable for high volume production are availab
45. E FLAME UPRIGHT PB TESTPOINTSMA LL BLKCON 100 V H TM1SQ W 1 00 1 XFORM COMB OMID SO8 NARROW 32QFNW GND SO8 NARROW SO8 NARROW LQFP 64 LCD VLS 6648 SOIC 8 XTAL ECS 39 71M6541 Demo Board REV 3 0 User s Manual P8 20KCCT ND CMF2 00MHFCT ND P1 00KHCT ND P62GCT ND P62GCT ND P20 0KCCT ND 541 6 04KCCT ND P62GCT ND 311 30KARCT ND RHM150CCT ND RHM8 06KCCT ND P25 5KCCT ND RR12P750DCT ND RR12P750DCT ND 541 3 40CCT ND 541 130FCT ND RG20P4 7KBCT ND RG20P270KBCT ND P10 0KHCT ND 541 10KACT ND 541 10KACT ND 100W 2 ND P13598SCT ND 5011K ND 5011K ND 296 1288 5 ND 768 1008 1 ND ADUM3201ARZ ND AT24C1024BW 5H25 B ND XC1658CT ND Panasonic 7D ERJ 6ENF8201V 196 0 125W Vishay Dale CMF552M0000FHEB 196 0 5W Vishay Dale ERJ 3EKF1001V 196 Panasonic ERJ 3GEYJ620V 596 Panasonic 596 Panasonic ERJ 6ENF2002V 3196 25W 1 8W Vishay Dale CRCW08056KO4FKEA 1 25W 1 8W Panasonic 7D ERJ 3GEYJ620V 596 1W 1 10W Yageo RCO805JR 0730KL 2596 25W 1 8W Rohm MCR10EZHF1500 196 25W 1 8W Rohm MCR10EZHF8061 3196 25W 1 8W Panasonic 7D ERJ 6ENF2552V 1 25W 1 8W Susumu RR1220P 751 D 196 Susumu RR1220P 751 D 0 596 Vishay Dale CRCW08053RA0FNEA 196 DNP Rohm CRCW1206130RFKEA 1 0 25W TDK RG2012P 472 B T5 0 Susumu RG2012P 274 B T5 0 Panasonic ERJ 3EKF1002V 1 Vishay Dale CRCW080510KOJNEA 5 Vishay Dale CRCW080510K0JNEA 596 DNP Yageo RSF200JB 100R 5 2W Panasonic EVQ PNFOSM KEYSTONE 5011 KEY
46. EV 3 0 Bottom Copper Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 4 4 71M6541 PINOUT INFORMATION Power Ground NC Pins Table 4 2 71M6541 Pin Description Table 1 3 Name Type Description GNDA P Analog ground This pin should be connected directly to the ground plane GNDD P Digital ground This pin should be connected directly to the ground plane V3P3A P Analog power supply A 3 3 V power supply should be connected to this pin V3P3A must be the same voltage as V3P3SYS V3P3SYS P System 3 3 V supply This pin should be connected to a 3 3 V power supply Auxiliary voltage output of the chip In mission mode this pin is connected to V3P3D o V3P3SYS by the internal selection switch In BRN mode it is internally Con nected to VBAT V3P3D is floating in LCD and sleep mode A bypass capaci tor to ground should not exceed 0 1 pF VDD o The output of the 2 5V regulator This pin is powered in MSN and BRN l modes A 0 1 uF bypass capacitor to ground should be connected to this pin VLCD o The output of the LCD DAC A 0 1 uF bypass capacitor to ground should be connected to this pin Battery backup pin to support the battery modes BRN LCD A battery or VBAT P super capacitor is to be connected between VBAT and GNDD If no battery is used connect VBAT to V3P3SYS 11 and oscillator power supply A battery or super capacitor is to be con VBAT RTC P nected between VBAT and GNDD If no battery is used connect VB
47. Hg Lp tok C64 C63 SSL LX5093SRC E PCB Linkage LCD HDR2X1 JP59 A DE 0 1uF 1000pF ira PNS amp PIN 36 PIN 6 amp PIN 35 PIN 7 8 PIN 33 VBAT RTC gal V3P3SYS PIN 8 amp PIN 32 PIN 9 amp PIN 30 PIN 10 amp PIN53 HDR2X1 dem icis m s l PIN 118 PIN52 PIN128PIN51 PIN13 amp PIN50 SEGDIO49 10000 BITS sf RB PIN 14 amp PIN49 PIN15 amp PIN48 1 16 amp PIN 47 D SEGDIO48 ee as BATTERY 9156556 eu LR 5 ve Se PIN17 amp PIN46 PIN18 amp PIN45 PIN19 amp PIN 44 Ju aji a zs i w on kan a ee a NP DNP sez esse R Note Place Ferrite Bead 600ohm PIN208PIN43 PIN21 amp PIN42 PIN22 amp PIN 41 al al oi 4 C1 C2 Y1 1 23 amp PIN40 PIN24 amp PIN39 PIN25 amp PN38 US EE EE d RGSS NG PIN 27 amp PIN 37 JP54 655 k JP57 ki close to U5 02 HDR2X1 ILU HDR2XILT IL HDR2X1 Sitt DOS tt A A TA 8 22ucouz tp o0325 us LCD VLS 6648 8 9 ESE ul 10pF Emulator HE FOGZIE COMS 1 56 COMO 505E 32 768KHz TOM 5 COM COMO 55 COMI STEE A si COMS 3 GOMA SOM 54 COM2 ICE Header SPI_DI 1 a SE 48 MN SEGDIO6 4 53 SEGDIO7 V3P3D z SPI DO 2 SELD SEGDIOSA cy oo vi IN 47 NBAT 110 SEGDI0365 A AYEY 52 SEGDIO4 E S SEGD10375 FE 13G 10 18 F t SEGDIO2Z I x Se 3 spicsziseapios veat L Pulli T JPS3forBRN SECT 7D 13A 13C DP2 2 2F SL oee ERST ng x COMI COMO V3P3SYS 744 IBP jump SEGDIO39g 7C 13B DP13 2D 2G 2A 29 SEGDIOS Te x COM2 6 COMI IBP 43 IBN
48. LTAGE 2 1 1 SENSOR WIRING The Demo Board is referenced to LINE voltage This means that the sensor wires have to be connected as shown in Figure 2 1 Shunt LINE Neutral m LOAD LINE IAN IAP AA Figure 2 1 Shunt Connections 34 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 2 1 2 SINGLE PHASE TWO WIRE EQU 0 This is the most basic configuration for this Demo Board The current sensor is connected directly to the IAP IAN inputs of the 71M6541 see Figure 2 2 The energy measurement is based on the following equation P VA IA See the explanation below Table 1 8 for the calculation of IMAX A second current sensor can be connected to the IBP IBP inputs of the 71M6541 for example to detect tamper ing see Figure 2 3 The second current sensor can be another shunt resistor that is isolated using the on board 71M6X0X Remote Sensor Interface The Demo Board has provisions for connecting either a shunt or a CT sensor but the default configuration is the shunt sensor connected via on board 71M6X0X Remote Sensor Interface See section 3 1 for details LINE Shunt E E LOAD N Distribution transformer 71M6541 AP pe IAN gt V3P3A amp VA Figure 2 2 Single Phase Two Wire Meter with Shunt Sensor LI
49. MUX N TP3 o EMULATOR I F 2 E x Mersa INP_IN INN IN LINE NEUTRAL Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product No circuit patent licenses are implied Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time Maxim Integrated 160 Rio Robles San Jose CA 95134 USA 1 408 601 1000 2012 Maxim Integrated Products Inc Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products Inc 71M6541 Demo Board REV 3 0 User s Manual Table of Contents 1 GETTING STARTED 23ANG AGA 5 Tai Gen aT Aa 5 1 2 Safety and ESD Notes ALAALA 5 1 3 Demo Kit Contents ci duode decken CCo ie 6 1 4 Demo Board Version EA EEEa Ena aasa a anaE nTa 6 L CU ug AA EE dee 6 1 6 Suggested Equipment not Included eene nennen nennen nnnm a nins nnne n nita seta anneanne 6 1 7 Demo Board Test Set p 5
50. Mn Set wake timer to n minutes for automatic return to brownout mode Command combinations RTDy m d w Day of week year month day weekday 1 Sunday If the weekday is omitted it is set automatically RTR Read Real Time Clock RTTh m s Time of day hr min sec RTAs t Real Time Adjust start trim Allows trimming of the RTC If s 0 the speed of the clock will be adjusted by t parts per billion PPB If the CE is on the value entered with t will be changing with temperature based on Y CAL Y CALC and Y CALC2 gt Access look up table for RTC compensation Example RTD05 03 17 5 Programs the RTC to Thursday 3 17 2005 RTA1 1234 Speeds up the RTC by 1234 PPB S0 Read the first four bytes in the look up table kad lue The Military Time Format is used for the 1 i e 15 00 is 3 00 PM Commands for Accessing the Trim Control Registers Allows user to read trim and fuse values Description Usage T option Command 14 Read fuse 4 TRIMM combinations T5 Read fuse 5 TRIMBGA T6 Read fuse 6 TRIMBGB Example T4 Reads the TRIMM fuse ISO These commands are only accessible for the 71M6541H 0 1 parts When used on a 71M6541 0 5 part Ed the results will be displayed as zero Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Reset Commands Description Watchdog control Usage W Ha
51. N Shunt resistor at Remote Interface IC Voltage divider for VA Rev 4 0 2 4 2 47 71M6541 Demo Board REV 3 0 User s Manual When analyzing the contribution of thermal errors for power equation 1 for single phase 3 wire systems we can write the equation as follows JA IB VA Cy Can IA Cg Cy VA Cos C IB Coy C 2 2 The terms used in the above equation are defined as follows P VA e VA voltage applied to the meter e Az current applied to the shunt S1 that is connected to the IAP IAN pins of the 71M6541 e B current applied to the shunt S2 that is connected via the Remote Interface IC e Cyp error contribution from the voltage divider e Caxz error contribution from the voltage reference of the 71M6541 e Csi error from the shunt resistor that is connected to the IAP IAN pins of the 71M6541 e Cszz error from the shunt resistor that is connected via the Remote Interface IC e Cex error contribution from the voltage reference of the Remote Interface IC The equation can be simplified as follows VA YE TA Ey VA Cyp Ca IB Csa IC 2 2 P Or p va tio as ra S BAGAN SOFTWARE FEATURES FOR TEMPERATURE COMPENSATION In the default settings for the Demo Code the CECONFIG register has its EXT TEMP bit bit 22 set which means that temperature compensation is performed by the MPU by controlling the GAIN ADJA and GAIN ADJB registers In this context GAIN ADJA controls both current and voltage
52. NE Shunt LOAD E E N Shunt 71M6XXX e 71M6541 IAP IAN SBP gt IBN 3 Bp VA amp V3P3A Figure 2 3 Single Phase Two Wire Meter with two Shunt Sensors When the Demo Code is using equation O the energy calculation and pulse generation is solely based on the primary shunt IAP IAN The readings from the second shunt can be obtained by the MPU in CE registers and used for tamper detection Since the shunt in the second current channel may be different from the shunt used 35 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual in the primary channel the CE code allows scaling between the two channels so that all energy calculations can be based on IMAX 2 1 3 SINGLE PHASE THREE WIRE EQU 1 36 This meter configuration see Figure 2 4 is used in North America ANSI market and parts of South America The energy measurement is based on the following equation P VA 2 IA IB Both current sensors can be shunt sensors The second current sensor may also be a CT The Demo Board has provisions for connecting either sensor type but the default configuration for the second current sensor is the connection via on board 71M6X0X Remote Sensor Interface Distribution transformer A Shunt VM LOAD A 8 113 LOAD LOAD B Shunt B 71M
53. OM2 o LCD Common Outputs These 4 pins provide the select signals for the COM 1 COMO LCD display Multi use pins configurable as either LCD segment driver or DIO AI ternative functions with proper selection of associated I O RAM regis ters are BEBO SEGDIOO WPULSE SEGDI019 SEGDIO1 VPULSE SN WO SEGDIO2 SDCK SEGDIC25 SEGDIO44 SEGDIO3 SDATA SEGDIO45 SEGDIO6 XPULSE f SEGDIO7 YPULSE Unused pins must be configured as outputs or terminated to V3P3 GNDD SEGDIO26 COMES VO Multi use pins configurable as either LCD segment driver or DIO with SEGDIO27 COM4 alternative function LCD common drivers SEGDIO36 Multi use pins configurable as either LCD segment driver or DIO with SPI_CSZ alternative function SPI interface SEGDIO37 SPI DO I O SEGDIO38 SPI_DI SEGDIO39 SPI CKI SEGDIO51 OPT TX lO Multi use pins configurable as either LCD segment driver or DIO with SEGDIO55 OPT RX alternative function optical port UART 1 a Multi use pins configurable as either emulator port pins when ICE_E pulled high or LCD segment drivers when ICE_E tied to GND E TCLK SEG49 O ICE enable When zero E RST E TCLK and E RXTX become ICE E SEG50 SEG49 and SEG48 respectively For production units this pin should be pulled to GND to disable the emulator port TMUXOUT SEG47 o Multi use pins configurable as either multiplexer clock output or LCD TMUX2OUT SEG46 segment driver using the I O RAM registers Chip reset This input
54. P63 9000000 0000 R12 SEGDIO 43 90 1 ALE wt ug te E 24 SEENEN a a anan annan SEGDIO254 n d E E 33 SEGDIO38 SERIAL EEPROM SEGDIO38 SEGDIO37 3 EE 100K NA SEGDIO234 33 SEGDIO38 before using DA LA D 1 CD DO ML CO DD LL CU SEGDI04g5 9C 18E 18E 11D 11G 11A 32 SEGDIO39 U4 5 a SPI head AD NM NN NN 0 0 NN C CD SEGDIO296 9A 18G 18D DP11 11C 11B 35 SEGDIO49 0 1uF Jee JP10 eager ll PPL PG V3P3SYS SEGDIO487 X7 X8 6 9B 18A 18C X14 12E 12F X12 X21 39 SEGDIOSS 1 8 V3P3D HDR2X1 1 EEEERSESEE EE SEGDIOs3s DP9 18B DP18 12D 12G 12A 55 SEGDIOSD 2 0 vce 7 eu SPI Interface slolstelol LL PE X15 10E 10F X9 X16 X22 DP12 12C 12B X11 X20 X19 ET 16 SDCK allele la l kakaks Da a D 2 A i lanp spa F2 1 WAS SDATA el Gi Jg 8959999993 35V USB P Note These pins must be assigned as indicated all 0 5651 3 4 HUH EE Hale e ec s es other pins can be swapped for layout purposes but SER EEPROM R104 R105 SPI CK O 6 T PCB linkages must remain intact SER EEPROM 10K 10K FUN CM m R z GND USB Aa 1 45V USB JPZ HDR2X1 V3P3SYS 1 5 8 V3P3SYS JI HDR 7Z SEGDI0511 2 a c7 RXUsB 2 VEDINDD2 P7 UART TX Tee 2 3 Sizes vz TX USB 3 vs YOn 6 UART RX ISO TX 1 BR pA Ap pre SEGDIOS51 CA 2 W L 40 10 GND USB 4 VB VOB L Jour HDR2X1 HDR2X1 pwa NG SM N JP8 HDR2X1 5 S BERKLZZYL 4001173201 KIA a sd 9 1K R103 SEGDIO36 SEGDIO39 a Sor TXRXLED CN1 pa Li Le use 618 lt 10K 1 24 1
55. PS 2381594 805 1206 603 805 603 609 3657 ND 445 1237 1 ND 445 1269 1 ND 478 3351 1 ND 445 1314 1 ND 478 1383 1 ND 587 1782 1 ND BC1609 ND 445 1298 1 ND 445 1314 1 ND 445 1298 1 ND P833 ND 445 1281 1 ND P5115 ND 445 1273 1 ND 478 1666 1 ND P963 ND 478 1672 1 ND BAS21FSCT ND S1J E3 61TGICT ND 1N4148WSFSCT ND 67 1612 ND L62415CT ND UCLAMP3301DCT ND S1011E 36 ND S1011E 36 ND S1011E 36 ND SC237 ND A24747CT ND A33555 ND S2011E 36 ND S2011E 36 ND 445 1556 1 ND 240 2546 1 ND BC857CINCT ND BCX70KINCT ND 541 1 0KACT ND RHMO OECT ND 541 0ROGCT ND 541 100KACT ND P100KGCT ND 594 2222 338 20224 594 2381 594 55116 FCI TDK TDK AVX Corporatic TDK AVX Corporatic Taiyo Yuden Vishay TDK TDK TDK Panasonic TDK Panasonic TDK Panasonic Panasonic AVN Fairchild Vishay Genera Fairchild Lumex CML Semtech Sullins Sullins Sullins Switchcraft Inc Tyco AMP Tyco AMP Sullins Sullins TDK Steward Infineon Techn Infineon AVX Vishay Dale Rohm Semicon Vishay Dale Vishay Dale Panasonic 806 KUSBVX BS1N W C1005C0G1H150J C1608COG1H100D 08055C104MAT2A C1608X7R1H104K 08055C103KAT2A TMK212BJ475KG T BFC233820224 C1608X7R2A102K C1608X7R1H104K C1608X7R2A102K ECE A1CKA101 C1608C0G1H101J ECA OJM102 C1608C0G1H220J TAJA336K006RNJ ECE A1AKS101 TAJB106K010R BAS21 S1J E3 61T 1N4148WS SSL LX5093SRC E CMD1
56. RAGA KANA SEENEN 46 2 4 1 ErtOt SOUE COS utes a th ftc has oS pun an Efe i fim i ebd onus 46 2 4 Software Features for Temperature Compensation 47 2 4 3 Calculating Parameters for 0111 061155110 1 nnns 48 2 5 Testing the Demo Board eese nnns nne ennn nnn ennn sss i nnns assem asas esas assi sms a sese sna ass snn asas enm a asse anna 51 2 5 1 Functional Meter Test ae RU ERR EE de E tede aa 51 2 6 Sensors and Sensor Placement nene nanasan nananana 53 2 6 1 Self Heating ei tap MATA gc ei e e lad dE CERS EES 53 2 6 2 Placement of Sensors ANSI rennen rs 54 2 6 3 Placement of Sensors EC 55 2 6 4 Other Techniques for Avoiding Magnetic 10059515 56 3 HARDWARE DESCRIPTION aa ge 2 2 58 3 1 71M6541 DB Description Jumpers Switches and Test Points 58 3 2 Board Hardware Specifications eeeeeeeceeeeeee esee ee
57. RFACE AND CONNECTED TO THE PHASE B IN PUT EXTREME CARE MUST BE TAKEN WHEN CHANGING SHUNT AND VOLTAGE CONNECTIONS 5 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 1 3 DEMO KIT CONTENTS e Demo Board 06541 REV 3 0 containing one 71M6601 or 71M6201 Remote Sensor Interface and one 71M6541F IC with pre loaded demo program e 5VDC 1 000mA universal wall transformer with 2 5mm plug Switchcraft 712A compatible e Serial USB converter e USB cable e ANSI base with 50 uQ shunt resistor optional for ANSI kits only or two 120 uQ shunt resistors 1 4 DEMO BOARD VERSIONS This manual applies to 06541 REV 3 0 only 1 5 COMPATIBILITY This manual applies to the following hardware and software revisions e 71M6541 chip revision B02 e Demo Kit firmware revision 5 4G or later e Demo Board D6541 REV 3 0 1 6 SUGGESTED EQUIPMENT NOT INCLUDED For functional demonstration e PC with Windows 2000 Windows XP or Windows 7 operating system equipped with USB port For the use of the optional Debug Board a serial interface COM port is required For software development MPU code e Signum Systems In Circuit Emulator ICE ADM 51 o Signum WEMUS1 version 3 11 09 or later should be used e Keil 8051 C Compiler Kit CA51 Windows and Windows XP are registered trademarks of Microsoft Corp 6 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 1 7 DEMO BOARD TEST SETUP Figure 1 1 shows the basic connections of the Demo Board
58. STONE 5011 DNP Midcom 750 11 0056 Texas Instrume TL431AIDR FTDI FT232RQR Analog Devices ADUM3201ARZ ATMEL AT24C1024BN SH25 B Teridian VARITRONIX VL 6648 VOO Teridian 71M6601 ECS ECS 327 12 5 39 TR Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 4 3 71M6541 DB PCB LAYOUT Tee ee e 5 e 6 W E E ROUT 5 VAR HEITE Ee VPULSES a nm oapzm T SEGDIOB GND ki eND XPULSE SEGDI06 e GND Vers ENTER V3P3SY OPT Tx EMULATOR I F GESER JI a INP_ IN INN IN a IS Be MAXIM DB6541 eee REV 3 0 9 e a N 3 eR 11 5 8 R10 EE R90 e C970 e c 1 ka Ln 28 SE V3P3SYS vaaTerTcle e TMUX2DUT 5 ERO PAN up oue B D pi mac15 R56 C10 C24 m C14 VaP3a wu S mo TAN ING B rap IN 6 9452 DOE a uut min Cy R13 DO Eh 010 E B VOLTAGE LINE NEUTRAL Figure 4 3 71M6541 DB REV 3 0 Top View 69 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 70 Figure 4 4 71M6541 DB REV 3 0 Top Copper Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 872 KE C60 z ef BZ ert H Nga arden e Q d e IAP_ M II IAN IN E e oo C32 e 2 JPA H 4142 gt o a 0049 NEUTRAL Figure 4 5 71M6541 DB REV 3 0 Bottom View 71 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 72 Figure 4 6 71M6541 DB R
59. TCHES AND TEST POINTS The items described in the following tables refer to the flags in Figure 3 1 Item Reference Designator Name Use TP2 GND GND test point JP58 D5 WPULSE Wh 2 pin header connected to the Wh pulse LED Wh pulse LED AJOJN D6 VARh VARh pulse LED JP1 BAT MODE Selector for the operation of the IC when main power is re moved A jumper across pins 2 3 default indicates that no external battery is available The IC will stay in brownout mode when the system power is down and it will communi cate at 9600bd A jumper across pins 1 2 indicates that an external battery is available The IC will be able to transi tion from brownout mode to sleep and LCD modes when the system power is down and it will communicate at 300bd JP44 XPULSE 3 pin header that connects XPULSE pin to the LCD The XPULSE pin should be configured as an LCD pin when a jumper is placed in the 1 2 position JP45 YPULSE 3 pin header that connects YPULSE pin to the LCD The YPULSE pin should be configured as an LCD pin when a jumper is placed in the 1 2 position JP53 U5 V3P3D 2 pin header that connects the VIP3D pin to parts on the board that use the V3P3D net for their power supply For supply current measurements in brownout mode the jumper on JP53 may be removed The IC 71M6541 soldered to the PCB 10 TP1 TMUXOUT TMUX2OUT Test points for acce
60. V 3 0 User s Manual maxim integrated REV 12 Date 5 4 2011 Author JPJ Curent lags 3 voltage ductive Positive irae direction capacitive Q4 4 4 EN Ee Energy Using Energy Figure 2 7 Calibration Spreadsheet for Three Measurements 43 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual maxim mE Results will show in green fields n t e g ra t e d Enter values in yellow fields AC frequency 60 Hz REV 2 click on yellow field to select from pull down list Date 5 4 2011 Sample Frequency 2520 615 Author JPJ FOT PHASE A Energy reading at 0 0 06015 CAL IA 16384 Energy reading at 60 0 05058 CAL VA 16384 Energy reading at 60 0 06971 L COMP2 A Energy reading at 180 Voltage error at 0 sel Current lags voltage se inductive Positive En i direction 60 C a urren PHASE B Energy reading at 0 0 06015 CAL IB 16384 17331 Energy reading at 60 0 05058 CAL_VB 16384 16487 Energy reading at 60 0 06971 L_COMP2_B 15776 Energy reading at 180 N Voltage error at 0 i H Expected voltage V 238 5 Measured voltage V Generating Energy Using Energy FA Voltage Readings Enter 0 if the error is 0 enter 5 if meter runs 5 fast enter 3 if meter runs 3 slow Figure 2 8 Calibration Spreadsheet for Five Measurements 44 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 2 3 7 COMPENSATING FOR NON
61. We use the other two measurements to determine de and Axi _ IV Ay Ay cos 0 ps 2 E 1 A A COS 1 IV cos 0 Uie s E 1 2a Ay Ay A cos p E LIV Aw An cos 60 9 TENES cos 60 s A IV cos 60 WT cos 60 Rev 4 0 2 2 2 38 71M6541 Demo Board REV 3 0 User s Manual Ay Ay cos 60 cos d sin 60 sin g cos 60 Ayy Ay COSL Ayy Ay tan 60 sin g l Combining 2a and 3a 4 Ej Ej E 1 tan 60 tan f 3a E 1 Eq Eo 5 Long YE E tan 60 Eo E 6 3 nl 2 3 E 1 tan 60 and from 2a E 1 7 gt A An Cos p Now that we know the Ayy Axi and bs errors we calculate the new calibration voltage gain coefficient from the previous ones QUE SU ES XV We calculate PHADJ from s the desired phase lag tan l 1 2 220 2 cos2f 7 1 27 sin 2zf T tan 6 1 1 27 cos 2zf T And we calculate the new calibration current gain coefficient including compensation for a slight gain increase in the phase calibration circuit CAL I 1 Ay 2 PHADJ 2 2 PHADJ 2 1 2 cos 22f T 1 2 1 2 cosQazf T 1 27 PHADJ cd CAL ly CALIBRATION WITH FIVE MEASUREMENTS The five measurement method provides more orthogonality between the gain and phase error derivations This method involves measuring Ev Eo E180 Een and Esoo Again set all calibration factors to nominal i e CAL IA 16384 C
62. XXXX 71M65XX TNR L JAP IAN A amp VA BP p IBN e amp V3P3A Figure 2 4 Single Phase Three Wire Meter with two Shunt Sensors By default the gain of the amplifier for the IAP IAN inputs is set to 1 See the explanation below Table 1 8 for the calculation of IMAX As for the single phase two wire configuration the CE code allows for scaling of differences between the cur rents in both phases so that all energy calculations can be based on IMAX Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 2 2 CALIBRATION THEORY 2 2 1 37 A typical meter has phase and gain errors as shown by bs Axi and Axy in Figure 2 5 Following the typical me ter convention of current phase being in the lag direction the small amount of phase lead in a typical current sensor is represented as s The errors shown in Figure 2 5 represent the sum of all gain and phase errors They include errors in voltage attenuators current sensors and in ADC gains In other words no errors are made in the input or meter boxes INPUT ERRORS METER SEH gt ts gt AQ 9 IDEAL I ACTUAL I Ay is phase lag s is phase lead D w IDEAL IV cos f NU ACTUAL IV Ay Ayy C0s Pr Ps Vnus V l Ay Hm vi gt IDEAL V ACTUAL V Axy ACTUAL IDEAL _ ACTUAL Sj IDEAL IDEAL ERROR Figure 2 5 Watt Meter with
63. alibrated load or a meter calibration system the board should be connected to the AC power source using the spade terminals on the bottom of the board The shunt resistor should be connected to the dual pin header labeled J3 on the bottom of the board The Kh value can be derived by reading the values for IMAX and VMAX i e the RMS current and voltage val ues that correspond to the 250mV maximum input signal to the IC and inserting them in the following equation for Kh Kh 109 1587 VMAX IMAX SUM SAMPS WRATE X See the explanation in section 1 10 4 for an exact definition of the constants and variables involved in the equa tion above ADJUSTING THE DEMO BOARDS TO DIFFERENT SHUNT RESISTORS The Demo Board is prepared for use with 120 u or 50 uQ ANSI option shunt resistors in both current chan nels For the Demo Board a certain current flowing through the 120 uQ shunt resistor will result in the maximum voltage drop at the ADC of the 71M6541 This current is defined as IMAX IMAX will change when different values are used for the shunt resistor s which will require that WRATE has to be updated as shown in section 1 10 4 USING THE PRE AMPLIFIER In its default setting the 71M6541 is applies a gain of 1 to the current input for phase A IAP IAN pins This gain is controlled with the PRE bit in I O RAM refer to the IC data sheet The command line interface RI command can be used to set or reset this bit It is recommend
64. an ex ceed n max before Count of accumulation intervals 10 secs ME signed 16 the neutral error is asserted Reseved Jo TI 32 bit unsigned number For ldentification num AMR demonstrations this is A ber of meter sent in decimal as the identifica 100900990 20 signed 32 tion number of the meter Refer to the IC data sheet Count of tempera Temperature is calculated as temp_datum ture sensor at cali temp measured_temp n a 21 signed 32 bration temp datum temp call temp cal0 Center temperature d GO 0 ofa meter element s 0 22C E signed 16 temperature curve A Refer to the IC data sheet Set Ba rude crystal s capacitor E when the IC data 26 unsigned adjustment sheet 2V ona real PCB should be adjusted for battery and chip Minimum valid bat Units of hardware s battery tery voltage measurement register Count of calibra Counts number of times calibra cal cnt 10115 In demo code tion is saved to a maximum of it also checks ad 255 justments B Checked to prevent old calibration data from being used by new code Value ver hash that changes with s s TA Hk a 2A unsigned the banner text and 9 therefore with the version date and time paro a e signed unsigned Checks calibrations In demo code it Checked by data ok of calibra also checks adjust tion value ments 27 Rev 4 0 data ok cal unsigned 71M6541 Demo Bo
65. ard REV 3 0 User s Manual state bit ar Status of meter Bits 8 See table below First 32 bit number is a count of Whanetovieatstat pulses 3 2 Wh in 3 phase me lan Slt 9 ters or 1 in 1 phase A fractional n a 31 64 a pulse is present in the CE data but not preserved Wh exported energy register Nonvola Like wh im n a 32 64 tile varh an VARR register Like wh_im n a 33 64 Nonvolatile varh ex VARR exported reg Like wh im ister Nonvolatile Time of maximum Standard time and date struc year month e i Battery voltage at last measurement VE Volatile not saved 91 i on power failure Count of accumula tion intervals since reset or last clear acc cnt Cleared with 1 2 or count n a 32 meter read Volatile not saved on power failure Counts seconds that tamper errors were asserted X F tamper sec Cleared with 1 2 or This is a tamper measurement n a signed 32 meter read Nonvol atile Counts seconds that voltage low This is a power quality meas sag_sec error occurred or urement p q y n a signed 32 meter read Nonvol i atile n a 36 40 Counts seconds that neutral current inse 5 error was asserted This is a power quality meas a Cleared with 1 2 or urement meter read Nonvol atile Clock time and date Standard time and date struc rtc copy when data was last ture year month date hour read from the RTC min sec register saves Valid only when autocal
66. ary for the straight DB9 cable and the pin definitions PC Pin Function Demo Board Pin 2 TX 2 3 RX 3 5 Signal Ground 5 Table 1 2 Straight Cable Connections Table 1 3 shows the connections necessary for the null modem DB9 cable and the pin definitions PC Pin Function Demo Board Pin 2 TX 3 3 RX 2 5 Signal Ground 5 Table 1 3 Null modem Cable Connections See Table 3 1 for correct placement of jumper JP5 on the Demo Board depending on whether the USB connec tion or the serial connection via the Debug Board is used Rev 4 0 1 7 3 1 7 4 71M6541 Demo Board REV 3 0 User s Manual CHECKING OPERATION A few seconds after power up the LCD display on the Demo Board should display a brief greeting in the top row and the demo code revision in the bottom row H E L L O 5 4 G The HELLO message should be followed by the display of accumulated energy 0 0 0 Wh SYS 0 3 The SYS symbol will be blinking indicating activity of the MPU inside the 71M6541 In general the fields of the LCD are used as shown below Measured value Unit Command number Phase SERIAL CONNECTION SETUP After connecting the USB cable from the Demo Board to the PC or after connecting the serial cable from the optional Debug Board to the PC start the HyperTermi
67. ature chamber a calibrated current and a voltmeter with filtering capabilities A few shunt resistors should be measured and their TC should be compared This type of information can also be obtained from the manufacturer For sufficient compensation the TC of the shunt resistors must be repeatable If the shunts are the only temperature dependent components in a meter and the accuracy is required to be within 0 5 over the industrial temperature range the repeatability must be better than R 5000 PPM C 60 C 83 3 PPM C This means that for a shunt resistor with 200 PPM C the individual samples must be within 116 7 PPM C and 283 3 PPM C Let us assume a shunt resistor of 55 uQ This resistor is 10 above the nominal value of 50 Q but this is of minor importance since this deviation will be compensated by calibration In a temperature chamber this resis tor generates a voltage drop of 5 4559 mV at 40 C and 5 541 mV at 85 C with 100 A applied This is equiva lent to a resistance deviation of 0 851 yO or 15 473 PPM With a temperature difference between hottest and coldest measurement of 125 C this results in 124 PPM C At high temperatures this resistor will read the current 60 C 124 PPM C or 0 744 too high This means that the GAIN ADJA and GAIN ADJB registers have to be adjusted by 0 744 at the same temperature to compensate for the TC of the shunt resistor Let us assume that only linear components ap
68. ce on the temperature characteristics of the meter Typically the TC of shunt resistors is linear over the industrial temperature range and can be com pensated granted the shunt resistor is at the same temperature as the on chip temperature sensors on the 71M6X0X Remote Sensor Interface IC or the 71M6541 Generally the lower the TC of a shunt resistor the better it can be compensated Shunts with high TCs require more accurate temperature measurements than those with low TCs For example if a shunt with 200 PPM C is used and the temperature sensor available to the 71M6543 is only accurate to 3 C the compensation can be inaccurate by as much as 3 C 200PPM C 600 PPM or 0 06 The reference voltage of the 71M6X0X Remote Sensor Interface IC At the temperature extremes this voltage can deviate by a few mV from the room temperature voltage and can therefore contribute to some temperature related error The TC of the reference voltage has both linear and quadratic com ponents TC and TC2 Since the 71M6X0X Remote Interface IC has an on chip temperature sensor and since the development of the reference voltage over temperature is predictable to within 40 PPM C compensation of the current reading is possible to within 60 C 40 10 PPM C or 0 24 The reference voltage can be approached by the nominal reference voltage VNOM T VNOM 22 T 22 TC T 22 TC2 Actual values for TC and TC can be obtained as follows TC 3 50 10
69. d dress 0x0000 4 A 0x1028 Commands for MPU XDATA Access MPU DATA ACCESS Comment Description Allows user to read from and write to MPU data space Usage Starting MPU Data Address option option Command A Read three consecutive 32 bit words in Decimal starting at combinations address A Read three consecutive 32 bit words in Hex starting at ad dress A A n m Write the values n and m to two consecutive addresses start ing at address A Display useful RAM addresses Example 08 Reads data words 0x08 OxOC 0x10 0x14 04 FFFFAD2 9A23 Writes two hexadecimal words starting 0x04 04 1000 Writes decimal 1 000 to address 0x04 04 1000 Writes decimal 1 000 to address 0x04 MPU or XDATA space is the address range for the MPU XRAM 0x0000 to OxFFF All MPU data words are in 4 byte 32 bit format Typing JA will access the 32 bit word located at the byte address 4 A 0x28 The energy accumulation registers of the Demo Code can be accessed by typing two Dollar signs typing question marks will display negative decimal values if the most significant bit is set 11 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Commands for LO RAM Configuration RAM and SFR Control Allows the user to read from and write to DIO RAM and special function registers SFRs combinations Description Usage R option register op
70. e BEE N Same units as CE s vOsqsum CE s wOsum units per pulse rounded up to next largest CE count so Wh accumulation and display is always rounded down signed Count of minutes 60 interval interval 60 unsigned unsigned Refer to the IC data sheet Temperature is calculated as temp measured_temp temp_datum temp_cal1 temp cal0 Refer to the IC data sheet ppm T mtr datum in 0 1 C ppm2 T mtr datum 2 in 0 1 C 13 Qa Q accumulation intervals cover both chop polar ities 2400 240 Visa standard full scale setup for meter test 300 30 A is a stand ard full scale setup for meter test Count of accumulation intervals of calibration 0 1V rms of AC signal applied to all elements during calibration 0 1A rms of AC signal applied to all elements during calibration Power factor of calibration signal must be 1 N a n 1 N Rev 4 0 lcd bit 26 Selects LCD s cur rent display Defines sequence of LCD displays Manufacturer s ID text string of the meter 71M6541 Demo Board REV 3 0 User s Manual 0 Meter identification 1 Display variation from calibra tion temperature 0 1C 2 Display mains Hz 0 1 Hz 3 mWh total 4 mWh total exported 5 mVARRh total 6 mVARRh total exported 7 mVAh total 8 Operating hours 9 Time of day 10 Calendar date 11 Powe
71. e 71 Figure 4 6 71M6541 DB REV 3 0 Bottom Copper 72 Figure 4 14 71M6541 LQFP64 Pinout Top View 75 List of Tables Table 1 1 Jumper Settings on Debug Board nnns 8 Table 1 2 Straight Cable 011116 110115 iee i aieeaii rennes 8 Table 1 3 Null modem Cable Connections 8 Table 1 4 CE RAM Locations for Calibration Constants 19 Table 1 5 Flash Programming Interface Signals 22 Table 1 6 MPU XRAM Locations a Ba Ne rx cue Dee Gum ami anG nan ba tee eke ke 24 Table 1 7 Bits in the MPU Status Word 29 Table 1 8 CE Registers and Associated LSB Values 30 Table 1 9 IMAX for Various Shunt Resistance Values and Remote Sensor 065
72. ed to maintain the gain of setting of 1 RI2704 0x90 USING CURRENT TRANSFORMERS CTs Phase B of the 71M6541 Demo Board can be equipped with a CT that may be connected at header J8 A bur den resistor of 1 7 Q or any other value may be installed at the R33 and R34 locations With a 2000 1 ratio CT the maximum current fort phase B will be 208 A Note The CT configuration will require a different version of the Demo Code Current measurements can be displayed for phase B by the demo code and the corresponding currents can be extracted by the MPU from the CE registers for tamper detection when using the Demo Code for EQU 0 IMPLEMENTING A SINGLE PHASE 3 WIRE METER EQU 1 This application will require two identical current sensors for each phase The simplest approach is to use iden tical shunt resistors for each channel ADJUSTING THE DEMO BOARDS TO DIFFERENT VOLTAGE DIVIDERS The 71M6541 Demo Board comes equipped with its own network of resistor dividers for voltage measurement mounted on the PCB The resistor values for the D6541 REV 3 0 Demo Board are 2 5477MQ R15 R21 R26 R31 combined and 7509 R32 resulting in a ratio of 1 3 393 933 This means that VMAX equals 176 78mV 3 393 933 600V A large value for VMAX has been selected in order to have headroom for Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual overvoltages This choice need not be of concern since the ADC in the 71M6541 has enough resolution even when op
73. emote Rated Max Voltage Shunt IMAX IMAX En WRATE for CE ad Sensor Current at IAP IAN Resistor A try at MPU kH 1 0 and dress Interface A mV Value uQ 0x03 VMAX 600 V 0x30 500 88 39 884 383 2483 400 110 49 1105 497 2483 300 147 31 1473 638 2483 71M6601 60 62 5 250 176 78 1768 766 2483 200 220 97 2209 957 2483 160 276 21 2762 1196 2483 120 368 28 3683 1595 2483 75 168 4 1684 729 8691 71M6201 200 17 86 50 252 6 2526 1094 8691 25 505 1 5051 2188 8691 The meter constant kh Wh per pulse is calculated as follows Kh 109 1587 VMAX IMAX SUM_SAMPS WRATE X where VMAX RMS voltage at the meter input corresponding to 176 8 mV RMS at the VA pin of the 71M6541 This value is determines by the divider ratio of the voltage divider resistors For the 71M6541 Demo Board this value is 600 IMAX RMS current through one current sensor corresponding to 176 8 mV RMS at the IAP IAN or IBP IBN pins of the 71M6541 as determined by the formula above Note For the IBP IBN pins no physical analog voltage exists due to the digital nature of the cur rent measurement via the remote interface SUM_SAMPS The value in the SUM SAMPS register in I O RAM 2520 for this version of the Demo Code WRATE The value in the pulse rate adjustment register of the CE X The pulse rate adjustment modifier determined by the PULSE FAST and PULSE SLOW bits in the CECONFIG register A kh of 1 1 00 W
74. erating at 120Vrms or 240Vrms If a different set of voltage dividers or an external voltage transformer potential transformer is to be used scaling techniques should be used In the following example we assume that the line voltage is not applied to the resistor divider for VA formed by R15 R21 R26 R31 and R32 but to a voltage transformer with a ratio N of 20 1 followed by a simple resistor divider We also assume that we want to maintain the value for VMAX at 600V to provide headroom for large voltage excursions When applying VMAX at the primary side of the transformer the secondary voltage Vs is Vs VMAX N Vs is scaled by the resistor divider ratio Ra When the input voltage to the voltage channel of the 71M6541 is the desired 177mV Vs is then given by Vs Rr 177mV Resolving for Rr we get Ra VMAX N 177mV 600V 30 177mV 170 45 This divider ratio can be implemented for example with a combination of one 16 95 kQ and one 100 resistor If potential transformers PTs are used instead of resistor dividers phase shifts will be introduced that will re quire negative phase angle compensation Maxim Integrated Demo Code accepts negative calibration factors for phase 1 9 CALIBRATION PARAMETERS 1 9 1 18 GENERAL CALIBRATION PROCEDURE Any calibration method can be used with the 71M6541F chips This Demo Board User s Manual presents cali bration methods with three or five measurements as recommended
75. esistor as shown above Let us assume applying 240 Vrms to a meter and recording the RMS voltage displayed by the meter at 40 C room tempera ture 55 C and at 85 C we obtain the values in the center column of Table 2 2 Table 2 2 Temperature Related Error Sources Temperature C Displayed Voltage Normalized Voltage 40 246 48 240 458 25 246 01 240 0 55 245 78 239 78 85 245 56 239 57 After normalizing with the factor 240 246 01 to accommodate for the initial error we obtain the values in the third column We determine the voltage deviation between highest and lowest temperature to be 0 88 V which is equivalent to 3671 PPM or 29 4 PPM C Finally we obtain a PPMCyp value of 788 2 4 3 5 Combining the Coefficients for Temperature Compensation 50 The TC formula for equation 2 is restated below VA Cyp IA Can run VA Dun Cay 1B Csa Cu 2 2 P After characterizing all major contributors to the TC of the meter we have all components at hand to design the overall compensation For simplification purposes we have decided to ignore Cyp For the control of GAIN ADJA we will need the following coefficients Cs1 The PPMC 3331 determined for the shunt resistor PPMC2 for the shunt resistor is 0 Cvp The PPMCyp value of 788 determined for the voltage divider Cax PPM Cay 820 and PPMC2 4y 680 We will find that coefficients can simply be added to combine the effects from several sources
76. g Rev 4 0 33 71M6541 Demo Board REV 3 0 User s Manual Send the Intel hex file built for operation with the bootloader e g 6541eq0 5p4g 07feb12 hex using the Send Text File command of HyperTerminal During the load procedure the Wh LED will blink Once the load process is completed it stops blinking The Wh LED should remain on solidly at the completion of the load procedure which indicates an error free load If the LED turns off at the end an error must have occurred In this case the load should be repeated The bootloader sends a 1 on the UART if the load succeeded and O if it failed Check the display of terminal program e g the PC running Hyperterminal If no checksum error has oc curred the bootloader sends a 1 on the UART In case of an error reset the DB6543 or turn it off and on and reload the code Remove the jumper on JP7 This will cause the loaded Demo Code to start Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 2 APPLICATION INFORMATION 2 1 SENSOR CONNECTIONS AND EQUATIONS The 71M6541 Demo Board supports the following meter configurations and equations e Single phase two wire EQU 0 e Single phase three wire EQU 1 Note Support of EQU 2 requires the 71M6542 IC which will be available on a separate Demo Board CAUTION THE DIAGRAMS SHOWN IN THIS SECTION ARE SYMBOLIC AND DO NOT REFLECT THE PHYSICAL CONNECTIONS OF THE DEMO BOARD e THE GROUND OF THE DEMO BOARD IS AT LINE LIVE VO
77. g the Demo Gode hex file aka AG RAR BA pope RAY RA T ponp ava S pi key 19 1 9 4 Updating Calibration Data in Flash or 2 1 0 20 1 9 5 Loading the Code for the 71M6541 into the Demo Board 20 1 9 6 The Programming Interface of the 71M6544 nennen nnne nnn 22 1 10 Demo Code 23 1 10 1 Demo Gode Desctiption e te e ig a edt e e elu uten tut 23 1 10 2 Important MPU Addresses ient ne Ede e Re ED ee 23 1 10 3 LSB Values iri CE Registers a Ie ect one e p e es Dee o Lo gu pet etd 30 1 10 4 Calculating IMAX and Khi cen cuo ma t Ann dee aides e coge cte are Rt 30 1 10 5 Determining the Type ot 71MOXOX emet oett ee ce rct tt pre ced cette ciat qe 31 1 10 6 Communicating with the 7 1 160 0 32 1 10 7 Bootloader Feat re ert DOUCEUR RERO 32 2 APPLICATION INFORMATION iicet orca trant nim G e a n e kk e kn kk ADD Da 34 2 4 Sensor Connections and Equations
78. grated circuit a 71M6601 Remote Interface IC peripheral circuitry such as a serial EEPROM emulator port and on board power supply A serial to USB converter allows communication to a PC through a USB port The Demo Board allows the evaluation of the 71M6541 energy meter chip for measurement accuracy and overall system use The board is pre programmed with a Demo Program Demo Code in the FLASH memory of the 71M6541F IC This embedded application is developed to exercise all low level function calls to directly manage the periph erals flash programming and CPU clock timing power savings etc The 71M6541F IC on the Demo Board is pre programmed and pre calibrated for the 50 uQ or 120 uQ shunt shipped with the board The Demo Board may also be used for operation with a CT after hardware modifica tions that can be easily performed by the user This configuration will require a different version of the Demo Code 1 2 SAFETY AND ESD NOTES Connecting live voltages to the demo board system will result in potentially hazardous voltages on the demo board THE DEMO SYSTEM IS ESD SENSITIVE ESD PRECAUTIONS SHOULD BE TAKEN WHEN HANDLING THE DEMO BOARD EXTREME CAUTION SHOULD BE TAKEN WHEN HANDLING THE DEMO BOARD ONCE IT IS CONNECTED TO LIVE VOLTAGES BOARD GROUND IS CLOSE TO LIVE VOLTAGE CAUTION THE PHASE A CONNECTION OF THE DEMO BOARD IS CONNECTED TO THE LIVE VOLTAGE SHUNT THE NEUTRAL SHUNT IS ISOLATED VIA THE 71M6X0X REMOTE SENSOR INTE
79. h per pulse is achieved by the following combination of system settings VMAX 600 V IMAX 368 3 A based on Rs 120 10 SUM SAMPS 2520 WRATE 1595 based on X 6 and PULSE FAST 0 and PULSE SLOW 0 1 10 5 DETERMINING THE TYPE OF 71M6X0X Sometimes it is useful to be able to determine the type of 71M6X0X Remote Sensor Interface that is mounted on the Demo Board The CLI can be used to find out which 71M6X0X Remote Sensor Interface is present us ing the following steps 1 2 3 31 Type 6R1 14 at the command prompt gt The CLI will respond with a two byte hex value e g E9DB Write the hex value out as binary sequence e g 1110 1001 1101 1011 Bits 4 and 5 determine the type of the 71M6X0X Remote Sensor Interface as shown in Table 1 10 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Table 1 10 Identification of 71M6X0X Remote Sensor Types Bit 5 Bit 4 71M6X0X Remote Interface Current Range A 00 71M6601 or 71M6603 60 01 71M6103 or 71M6113 Poly Phase 100 10 71M6201 or 71M6203 200 11 Invalid e 1 10 6 COMMUNICATING WITH THE 71M6X0X Some commands are useful to communicate with the 71M6X0X Remote Sensor Interface for the purpose of test and diagnosis Some useful commands are 1 6C1 42 this command causes the 71M6X0X Remote Sensor Interface to output its reference voltage on the TMUX pin pin 5 2 6R1 20 this command returns the reading from the tempera
80. h the 71M6541 38 US LCD 3 row LCD with 6 7 segment digits per row and special metering symbols 39 JP59 VPULSE 2 pin header connected to the VARh pulse LED 2 pin header for connection of the RX output of the isolated USB port to the RX pin of the 71M6541 When the Demo 40 JP5 UART RX ROUT Board is communicating via the USB port a jumper should be installed on JP5 When the Demo Board is communi cating via the Debug Board plugged into J21 the jumper should be removed Table 3 1 71M6541 DB REV 3 0 Description 60 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Figure 3 1 71M6541 DB REV 3 0 Board Description Default jumper settings are indicated in yellow 61 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 3 2 BOARD HARDWARE SPECIFICATIONS PCB Dimensions Width length Thickness Height w components Environmental Operating Temperature Storage Temperature Power Supply Using internal AC supply DC Input Voltage powered from DC supply Supply Current Input Signal Range AC Voltage Signal VA AC Current Signals IA from Shunt CT Interface Connectors DC Supply J20 Emulator J14 Voltage Input Signals Current Input Signals USB port PC Interface Optional Debug Board J2 SPI Interface Functional Specification Program Memory NV memory Time Base Frequency Controls and Displays RESET PB Numeric Display Wh VARh Measurement Range Voltage Current 62 134 mm x 1
81. hat is shown in Figure 2 10 48 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual GAIN ADJ 16410 16400 I 2 1 4 16390 16380 16370 16360 16350 16340 16330 16320 16310 40 20 0 20 40 60 80 Figure 2 10 GAIN ADJ over Temperature Some curve fitting is required to find PPMC y and PPMC2 y coefficients that will generate the desired behavior of the GAIN ADJ register For this case PPMC y 960 and PPMC2 y 610 approach the curve very accu rately The maximum deviation between GAIN ADJ and the GAIN ADJ synthesized by PPMC and PPMC2 coefficients is 0 00435 Figure 2 11 shows how both functions almost overlap GAIN ADJ E GAIN ADJ Figure 2 11 GAIN ADJ and GAIN ADJ over Temperature 49 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 2 4 3 3 Reference Voltage of the 71M6541 At a later time it will be shown how the compensation coefficients for the reference voltage of the 71M6541 can be derived For the moment let us assume that we know these coefficients and that they are PPMC y 820 and PPMC2yy 680 2 4 3 4 Voltage Divider In most cases especially when identical resistor types are used for all resistors of the voltage divider ladder the TC of the voltage divider will be of minor influence on the TC of the meter If desired the voltage divider can be characterized similar to the shunt r
82. heet It does not matter which current value is chosen as long as the corresponding error value is significant 1 error at 1 0 A used in the above equation will produce the same result for QUANT Input noise and truncation can cause similar errors in the VAR calculation that can be eliminated using the QUANT_VAR variable QUANT_VAR is determined using the same formula as QUANT The internal power supply generates a ripple on the supply and ground nets that is 90 phase shifted with re spect to the AC supply voltage This affects the accuracy of the VARh measurements If optimization of the VARh accuracy is required this can be done by writing a value into the QUANT_VAR register of the CE Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 2 4 TEMPERATURE COMPENSATION 2 4 44 ERROR SOURCES For a meter to be accurate over temperature the following major sources of error have to be addressed 1 The resistance of the shunt sensor s over temperature The temperature coefficient TC of a shunt resistor is typically positive PTC and can be far higher than the TC of the pure Manganin material used in the shunt TCs of several hundred PPM C have been observed for certain shunt resistors A shunt resistor with 100 PPM C will increase its resistance by 60 C 100 10 5 PPM C or 40 696 when heated up from room temperature to 85 C causing a relative error of 40 696 in the current reading This makes the shunt the most pronounced influen
83. ibration is integrated Meters with metering equations with differential currents or voltages do not normally support autocalibration Requires features not in some demo PCBs 28 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 3 Three phase ICs only Some CE codes calculate neutral current rather than measuring it Consult the CE documenta tion Only in systems with two current sensors 5 High accuracy use of this feature may require a calibrated clock IEC 62056 Manufacturers IDs are allocated by the FLAG Association Limited Maxim Integrated does not own or profit from the FLAG association Maxim Integrated s default id may not conform and is for demonstration purposes only 7 Nothing in the document should be interpreted as a guarantee of conformance to a third party software specification Conformance testing is the responsibility of a meter manufacturer May require calibration for best accuracy Calibration item in high precision H series meters 71M6541H only Table 1 7 Bits in the MPU Status Word Name Bit Explanation No MINIA 0 IA is below IThrshld Current for this phase is in creep MINIB 1 IB is below IThrshld Current for this phase is in creep MINIC 2 IC is below IThrshld Current for this phase is in creep MINVA 3 VA is below VThrshld Voltage for this phase is in creep MINVB 4 VBis below VThrshld Voltage for this phase is in creep
84. le from BPM Microsystems www bpmmicro com In Circuit Emulator firmware exists in the 71M6541F flash memory it has to be erased before loading a new file into memory Figure 1 5 and Figure 1 6 show the emulator software active In order to erase the flash memory the RESET button of the emulator software has to be clicked followed by the ERASE button To successfully erase the flash memory the following steps have to be taken 1 Disable the CE by writing 0x00 to address 0x2000 2 Write 0x20 to address 0x2702 FLSH UNLOCK register in I O RAM 3 Reset the demo board RESET button or power cycle 4 Activate the ERASE button in the WEMU51 user interface 5 Now new code can be loaded into the flash memory Once the flash memory is erased the new file can be loaded using the commands File followed by Load The dialog box shown in Figure 1 6 will then appear making it possible to select the file to be loaded by clicking the Browse button Once the file is selected pressing the OK button will load the file into the flash memory of the 71M6541F IC At this point the emulator probe cable can be removed Once the 71M6541F IC is reset using the reset button on the Demo Board the new code starts executing Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Statusi ADMS1 41807 CPU 71M6543 0000 BANK 0 DETRI 0000 acc 00 7 00 TE 00 cy 0 acl 200 07 01 0 10 mr mer R200 RI 00 R4 C2 RE 00 R 00
85. lts the Demo Code program thus suppressing the trigger ing of the hardware watchdog timer This will cause a reset if the watchdog timer is enabled Commands for the 71M6X0X Remote Sensor Interface Description Commands for control of the Re mote Sensor Interface IC Usage 6En Remote sensor Enable 1 3 Enable 0 Disable 6Ra b Read Remote Sensor IC number a with command b 6Ca b Write command b to Remote Sensor IC number a 6Ta b Send command b to Remote Sensor IC number a in a loop forever 612 Send temp command to 6000 number 2 in a loop forever 6R1 20 Reads the temperature from Remote Sensor IC number 1 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Commands for Controlling the Metering Values Shown on the LCD Display Text or Nu CLI merical Dis Egfmand Displayed Parameter s play 0 24 5 C 0 Temperature difference from calibration temperature ER _ Gabi 03 after power up or reset M m a Paa NN Paa _ Wi La ana ki a mama 00 KENT Date yy mm dd Katz BERE EC om ms mo 4 KA 6 7 8 11 Power factor P phase Not used in the 71M6541 Zero crossings of the mains voltage 1 Duration of sag or neutral current s BIN M15 P RMS current P phase ird V we RMS voltage e d Battery voltage 241 34W 1 1 50400 W SECHER 88 88 88 LCD Test Displays for total consumption wrap around at 999 999Wh or VARh VAh due
86. ly twisted to avoid loops that can be penetrated by the magnetic fields of the sen sors or conductors Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 2 6 3 PLACEMENT OF SENSORS IEC The arrangement of the current terminals in a typical IEC meter enclosure predetermines the spacing of the shunts and usually allows for only for 20 to 22 mm center to center spacing between the shunts This means that the clearance between adjacent shunts is typically only 10 mm or less A typical arrangement is shown in Figure 2 15 left side This arrangement is not optimized for suppression of cross talk In order to minimize cross talk between phases the shunts should be turned by 90 degrees as shown in Figure 2 15 right side In this arrangement the sensitive areas of the shunts are kept away from the adjacent currents e NC So kou i Gees ik Figure 2 15 Typical Sensor Arrangement left Recommended Arrangement right Other arrangements are shown in Figure 2 16 In the left figure the shunts are shown swiveled by 90 degrees towards the terminals In the right figure the shunts are shown staggered in height for example by using spac ers It is useful to minimize the loop area formed by the Manganin zone of the shunts and the wires As with the AN SI sensors it is recommended that sensor wires are tightly twisted to avoid loops that can be penetrated by the magnetic fields of the sensors or conductors
87. maxim integrated 71M6541 Demo Board REV 3 0 User s Manual Rev 4 0 12 12 TP2 m ug 9990090000000000000000000009 e e Ge 2 56 29 v3p3svs m AN ki MAXIM amp wuel e DB6541 RE UART ak D5 D D ae e e D V3P3SYSH an VPULSES li e s H x 6111 R10 D e k R9 t ka C97 ng z 6 S o e e k le RA Sus an ee ki ka ee a LT ee 12 e sa aj R4 We 00000000000000000000000009 iB P Y l e e RESET D e is e amp vaPssvs m m 03830 VBATeRTC e D e sescDIDS e UND g Ei D Seu enn salt XPULSE Fa mj sEGDIO6 Le aa m LI ee e SP1 D0 Ze SEGDIOSS ou pig Ble eseis gm sb 25 v Sil ener RX N TT x o os le v3P3sYS 0 O x D 600 1_1 ET o IM INVSP3SY a m w W SEGDIOSI s Eu eile ei a 555 mum jm a p W GND T er E V3P3D c X p vis flies e gt T
88. mulation variables are 64 bits long and are accessed with n read and n hh ll write in the case of accumulation variables The first part of the table the addresses 00 1F contains adjustments i e numbers that may need adjust ment in a demonstration meter and so are part of the calibration for demo code In a reference meter these may be in an unchanging table in code space The second part 20 2F pertains to calibration i e variables that are likely to need individual adjustments for quality production meters The third part 30 pertains to measurements i e variables and registers that may need to be read in a demonstration meter 23 Rev 4 0 i min v min v max 24 Metering element enters creep mode if current is below this value If 0 creep logic is disabled In creep mode on each me tering element Wh VARN i0sqsum and other items are zeroed Configure meter operation on the fly error if below Also creep Below this low volt age seconds are counted Voltage Wh VAR Fre quency and other voltage dependent items are zeroed Scaling Maximum Amps for standard sensor Scaling Maximum Volts for PCB Error if exceeded 71M6541 Demo Board REV 3 0 User s Manual Table 1 6 MPU XRAM Locations Default Same units as CE s iOsqsum 0110 1 Display KWh bit1 1 clear accumulators er rors etc e g 1 2 bit2 12 Reset demand e g 1 4 bi
89. nable the internal supply a jumper needs to be installed across JP6 on the top of the board o External 5 0VDC connector J20 on the Demo Board CABLES FOR SERIAL COMMUNICATION 1 7 2 1 USB Connection Recommended A standard USB cable can be used to connect the Demo Board to a PC running HyperTerminal or a similar se rial interface program A suitable driver e g the FTDI CDM Driver Package must be installed on the PC to en able the USB port to be mapped as a virtual COM port The driver can be found on the FTDI web site www ftdichip com See Table 3 1 for correct placement of jumper JP5 depending on whether the USB connection or the serial connection via the Debug Board is used 1 7 2 2 Serial Connection via Optional Debug Board For connection of the DB9 serial port of the Debug Board to a PC serial port COM port either a straight or a so called null modem cable may be used JP1 and JP2 are plugged in for the straight cable and JP3 JP4 are empty The jumper configuration is reversed for the null modem cable as shown in Table 1 1 Cable Configura Jumpers on Debug Board A Mode 5 tion JP1 JP2 JP3 JP4 Straight Cable Default Installed Installed Null Modem Cable Alternative x 7 Installed Installed Table 1 1 Jumper Settings on Debug Board JP1 through JP4 can also be used to alter the connection when the PC is not configured as a DCE device Ta ble 1 2 shows the connections necess
90. nal application and create a session using the following parameters Port Speed 9600 bd Data Bits 8 Parity None Stop Bits 1 Flow Control XON XOFF When using the USB connection you may have to define a new port in HyperTerminal after selecting File 3 Properties and then clicking on the Connect Using dialog box If the USB to serial driver is installed see sec tion 1 7 2 1 a port with a number not corresponding to an actual serial port e g COM5 will appear in the dia log box This port should be selected for the USB connection HyperTerminal can be found by selecting Programs gt Accessories gt Communications from the Windows start menu The connection parameters are configured by selecting File 3 Properties and then by pressing the Con figure button Port speed and flow control are configured under the General tab Figure 1 3 left bit settings are configured by pressing the Configure button Figure 1 3 right as shown below A setup file file name Demo Board Connection ht for HyperTerminal that can be loaded with File 3 Open is also provided with the tools and utilities Port parameters can only be adjusted when the connection is not active The disconnect et button as shown in Figure 1 2 must be clicked in order to disconnect the port Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual amp Demo Board Connection HyperTerminal File Edit Vien all Transfer Help Flow Control irect method Mete
91. ns Corrected Figure 2 2 Add 2 6 8 16 2010 ed text in Application Section explaining the change from PHADJ_A to DLAYADJ_A compensation coefficients Updated Calibration Spreadsheets Updated schematics PCB layout and BOM information to Demo Board Revision 3 0 Removed references to Debug Board Added information on avoiding cross talk between shunt resistors Corrected equation for QUANT 3 0 5 10 2011 Removed text stating that the Demo Code and documents tools are delivered on a CD ROM in the kit Added attribute optional for all references to the Debug Board Added USB Interface Module as part of Demo Kit Contents Updated sample images of calibration spreadsheets and added text stating that 4 0 12 12 spreadsheets are available on the Maxim Integrated web site Corrected part number for remote sensor IC 71M6601 Added sources for TPF2 Flash Programmer Updated company logo Replaced Teridian Semiconductor with Maxim Integrated where applicable 76 Rev 4 0
92. o Calculate the new calibration factors CAL In CAL Vn and PHADJ n using the formulae presented in section 2 2 2 or using the spreadsheet presented in section 2 3 6 Apply the new calibration factors CAL In CAL Vn and PHADJ n to the meter The memory loca tions for these factors are given in section 1 9 1 Test the meter at nominal current and if desired at lower and higher currents and various phase an gles to confirm the desired accuracy Store the new calibration factors CAL In CAL Vn and PHADJ n in the EEPROM or FLASH memory of the meter If a Demo Board is calibrated the methods involving the command line interface shown in sections 1 9 3 and 1 9 4 can be used Repeat the steps 1 through 7 for each phase For added temperature compensation read the value TEMP RAW CE RAM and write it to TEMP NOM CE RAM If Demo Code 4 6n or later is used this will automatically calculate the cor rection coefficients PPMC and PPMC2 from the nominal temperature and from the characterization da ta contained in the on chip fuses Tip Step 2 and the energy measurement at 0 of step 3 can be combined into one step 2 3 6 CALIBRATION SPREADSHEETS Calibration spreadsheets are available from Maxim Integrated Figure 2 7 shows the spreadsheet for three measurements Figure 2 8 shows the spreadsheet for five measurements with three phases 42 Different tabs are to be used for equation 0 2 and equation 1 For the calibration data sh
93. o 63 D Status 3 ADMS1 41807 CPU 71M6543 0000 BANK 0 DPTR 0000 DETRI 0000 ZAM Hex ESOS Ne Spa demo may0 Ne Fey Hex Loading Bank Diet Load Ssmbek ep 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 7233333222 333323222333332222333332233333222333333 23333323223333223222233333222333232322223333222233337 23333332223333332233333322333333223333322323333332 23333 31 33233 3332 3 32 22 32 33 32 22 232 232122 23 32 33 2 RARA AA AAA AAA SAY 353303321222 ttt paiet 21222 2 23 33 21 2 233333 12233 732 22 22 22 222 22 2 233 222222 ee 22 2 222 2223 23334332323333332233333332323333332333333323333333 23333352523333332233333332333333322323333313223333333 Figure 1 6 Emulator Window Showing Erased Flash Memory and File Load Menu Flash Programmer Module TFP 2 The operational firmware of the TFP2 will have to be upgraded to revision 1 53 Follow the instructions given in the User Manual for the TFP 2 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 1 9 6 THE PROGRAMMING INTERFACE OF THE 71M6541 Flash Downloader ICE Interface Signals The signals listed in Table 1 5 are necessary for communication between the Flash Downloader or ICE and the
94. ores calibration and other settings to defaults CLB Start auto calibration based on voltage MPU address 0x17 current MPU 0x18 and duration MPU 0x16 in seconds CLC Apply machine readable calibration control Intel Hex Records CPA Start the accumulating periodic pulse counters CPC Clear the pulse counters CPDn Activate pulse counters for n seconds Example CEO Disables CE SYS will stop blinking on the LCD CT1 3 Selects the VBIAS signal for the TMUX output pin Commands for Identification and Information Description Usage Allows the user to read information messages Sends complete demo code version information on serial inter face MO Displays meter ID on LCD The command is mainly used to identify the revisions of Demo Code and the contained CE code Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 14 Commands for Battery Mode Control and Battery Test Commands for Controlling the RTC Description Usage RT option value value Allows the user to read and set the real time clock Description Allows the user to control battery modes and to test the battery Usage BL Enters LCD mode when in brownout mode B prompt BS Enters sleep mode when in brownout mode B prompt BT Starts a battery test when in mission mode prompt BWSn Set wake timer to n seconds for automatic return to brownout mode BW
95. ould be entered into the calibration spreadsheets as follows 1 2 Calibration is performed one phase at a time Results from measurements are generally entered in the yellow fields Intermediate results and calibra tion factors will show in the green fields The line frequency used 50 or 60HZO is entered in the yellow field labeled AC frequency After the voltage measurement measured observed and expected actually applied voltages are en tered in the yellow fields labeled Expected Voltage and Measured Voltage The error for the voltage measurement will then show in the green field above the two voltage entries The relative error from the energy measurements at 0 and 60 are entered in the yellow fields labeled Energy reading at 0 and Energy reading at 60 The corresponding error expressed as a fraction will then show in the two green fields to the right of the energy reading fields The spreadsheet will calculate the calibration factors CAL IA CAL VA and PHADJ A from the in formation entered so far and display them in the green fields in the column underneath the label new If the calibration was performed on a meter with non default calibration factors these factors can be entered in the yellow fields in the column underneath the label old For a meter with default calibra tion factors the entries in the column underneath old should be at the default value 16384 Rev 4 0 71M6541 Demo Board RE
96. pear in the formula below i e PPMC2 is zero DELTA T PPMC DELTA T PPMC2 gu ZE ge We must now find the PPMC value that decreases GAIN ADJ by 0 744 when DELTA T is 600 DELTA T is measured in tens of C We find PPMC to be PPMC 2 16263 16385 600 3331 GAIN _ ADJ 16385 2 4 3 2 Remote Sensor Reference Voltage Above the contribution of the TC from the shunt resistor we will have to take into account the linear and quad ratic deviation of the reference voltage of the Remote Sensor Interface IC As mentioned above we have to read the TRIMT register of the Remote Sensor Interface IC This can be done with the CLI command gt 6R1 10 Let us assume the command gt 6R1 10 returns the value 9082 which we can interpret as the binary sequence 1001 0000 1000 0010 The value of TRIMT is contained in the bits 1 through 8 i e 0100 0001 or 65 decimal We can now calculate the TCs of the reference voltage VREF for the Remote Sensor Interface IC TC 3 50 10 6 04 10 TRIMT 3 5010 6 04 10 65 42 6 10 TC2 8 11 107 4 19 10 TRIMT 8 1107 4 19 10 65 5 39 107 These coefficients are in V C somewhat different from the p V C given in other data sheets Using these co efficients we obtain 1 19557 V at 40 C and 1 19018 V at 85 C assuming VREF was trimmed to 1 195 V at room temperature If we had to compensate only for VREF GAIN ADJ would have to follow the curve of VREF t
97. plus optional Debug Board with the external equip ment The PC can be connected via the USB Interface CN1 For stand alone testing without AC voltage the Demo Board maybe powered via the 5 0 VDC input J20 The optional Debug Board must be powered with its own 5 VDC power supply DEMONSTRATION METER 6541 Single Chip Meter PULSE OUTPUTS N L SEGDIO0 WPULSE E V3P3SYS o d External SEGDIO1 VPULSE HBD Vapagys Shunts m SEGDIO6 XPULSE O PULSE A e IAP SEGDIO7 YPULSE O PULSE B MENENENENENG le BAN ol J1 CT CC LI LI av orsv Y aaa EE o em a SE RE m m EE o IBN SDATA 9 LILILITITI TIL J5 e ETHEJHENIETHEIHENTE V3P3A SPI Connector J19 V3P3SYS ICE Connector J14 9 t VA 8 E NEUTRAL 50VDG YA Jo PEBUG BOARD OPTIONAL WZ Input i B a MPU HEARTBEAT 5112 JP6 ol e 1 SEGDIO52 OPT V5 DBG U oH Power Supply JP20 2 t x CE HEARTBEAT 1Hz SEGDIO10 gt oPTO V5 DBG 3 GND LINE J B 1 IG PTO NS GND DBG V3P3 V5_DBG 10 TX e gt OHOH 0PTO O RS 232 m Patay INTERFACE JES
98. r Display Select Wh Consumption for all sil 04 21 2005 ANSIW 9600 8 N 1 Figure 1 2 HyperTerminal Sample Window with Disconnect Button Arrow Pera 230401 vow moc modem Ais ax General Advanced Port Settings r Call preferences 1 Disconnect a call if idle for more than by mins Bte perisecond Cancel the call if not connected within 60 secs Data bits 8 las Data Connection Preferences Parity None z Port speed 9500 zl Stop bits hn s Standard EC isi Data Protocol Compression Disabled w n Flow control on Xoff X Restore Defaults Cancel Cancel Figure 1 3 Port Speed and Handshake Setup left and Port Bit setup right Once the connection to the demo board is established press lt CR gt and the command prompt gt should ap pear Type gt to see the Demo Code help menu Type gt i to verify the demo code revision 1 8 USING THE DEMO BOARD The 71M6541 Demo Board is a ready to use meter prepared for use with external shunt resistors Demo Code versions for single phase two wire operation EQU 0 with secondary tamper sensor and for sin gle phase three wire operation ANSI configuration EQU 1 are provided by Maxim Integrated Demo Boards in ANSI configuration are preloaded with Demo Code for EQU 1 Demo Boards in IEC configuration are preloaded with Demo Code for EQU 0 Using the Demo Board involves communicating
99. r factor total 12 Angle between phase 0 amp 1 13 Main edge count last accu mulation 14 KW instantaneous total 15 V instantaneous max of all phases 16 A total 17 V Battery VB 18 Seconds bad power BPS 3 19 Seconds tamper tamper in progress TS 20 LCD Test Scrolling not standard for these 111 PF phase 0 112 Angle phase 0 amp 1 114 KW phase 0 115 V phase 0 116 A phase 0 211 PF phase 1 212 Angle phase 0 amp 2 214 KW phase 1 215 V phase 1 216 A phase 1 311 PF phase 2 312 Angle phase 2 0 314 KW phase 2 315 V phase 2 316 A phase 2 416 A neutral measured The value is a bit mask that de scribes a scrolling display se quence Each set bit permits a display with an lcd idx value from 0 31 Each is displayed for 7 seconds Ordered by increas ing bit number If value is zero display does not change 3 ASCII bytes in MSB of 32 bit number Least significant byte TSC should be zero For AMR 0x54534300 demonstrations sent as the manufacturer s ID of the meter a M Rev 4 0 signed 71M6541 Demo Board REV 3 0 User s Manual Like max except for the 2nd current sensor Currents Wh etc using currents from 0 1 Amps 208 A 2080 1C signed 16 the second sensor are rescaled into the same units as the first current sensor E Maximum valid neu SW e The time that neu tral current c
100. readings for phase A i e the VA and IAP IAN pins whereas GAIN ADJB controls both current and voltage readings for phase B i e the VA and the 71M6X0X Remote Sensor Interface IC In general the GAIN ADJA and GAIN ADJB registers offer a way of controlling the magnitude of the voltage and current signals in the data flow of the CE code A value of 16385 means that no adjustment is performed unity gain which means that the output of the gain adjust function is the same as the input A value of 9996 of 16385 or 16222 means that the signal is attenuated by 1 The Demo Code bases its adjustment on the deviation from calibration room temperature DELTA T and the coefficients PPMC and PPMC2 to implement the equation below DELTA T PPMC DELTA T PPMC2 24 223 GAIN ADJ 16385 It can be seen easily that the gain will remain at 16385 0x4001 or unity gain when DELTA T is zero For complete compensation the error sources for each channel have to be combined and curve fit to generate the PPMC and PPMC2 coefficients as we will see in the following section The PPMC and PPMC2 coefficients are in the following MPU RAM locations e Phase A IAP IAN pins PPMCA 0x0B PPMC2A 0x0F e Phase B IBP IBN pins PPMCB 0x0C PPMC2B 0x10 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 2 4 3 CALCULATING PARAMETERS FOR COMPENSATION 2 4 3 1 Shunt Resistors The TC of the shunt resistors can be characterized using a temper
101. s every second for up to 20 seconds REGISTER BAD 17 Setafter reset when the read of the power register data has a bad longitudinal redundancy check or bad software version in all 5 copies Unlikely to be an accident RTC TAMPER 18 Clock set to a new value more than two hours from the previous value TAMPER 19 Tamper was detected Normally this is a power tamper detected in the creep logic For exam ple current detected with no voltage Table 1 8 contains LSB values for the CE registers used in the CE code for EQU 0 and EQU 1 All values are based on the following settings e Gain in amplifier for IAP IAN pins selected to 1 e 71M6103 or 71M6113 Remote Sensor Interface is used Note that some of the register contents can be zeroed out by the MPU when it applies functions contained in its creep logic 29 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 1 10 3 LSB VALUES IN CE REGISTERS Table 1 8 CE Registers and Associated LSB Values Register Name LSB Value Comment The real energy for element 1 IA VA measured in Wh per accumu WOSUM X 1 55124 10 7 IMAX VMAX lation interval The reactive energy for element 1 IA VA measured in VARh per VAROSUM X 1 55124 10 IMAX VMAX accumulation interval The real energy for element 2 IB VA measured in Wh per accumu WISUM X 1 55124 10 IMAX VMAX lation interval The reactive energy for element 2 IB VA
102. ss to the TMUXOUT and TMU2XOUT pins on the 71M6541 11 BT1 Location of optional battery for the support of battery modes Located on the bottom 12 BT2 Location of optional battery for the support of RTC and non volatile RAM BT2 has an alternate circular footprint at location BT3 58 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Item Reference Designator Name Use 13 J21 DEBUG Connector for Debug Board 2x8 pin male header 14 SW5 RESET Chip reset switch When the switch is pressed the RESET pin of the IC is pulled high which resets the IC into a known state 15 J12 2 pin header If a jumper installed the battery BT1 will be connected to the V3P3SYS net 16 J13 2 pin pin header If a jumper installed the battery BT2 BT3 will be connected to the V3P3SYS net 17 BT3 Alternate footprint for BT2 A circular battery may be mounted in this location on the bottom of the board 18 SW3 PB Pushbutton connected to the PB pin on the IC This push button can be used in conjunction with the Demo Code to wake the IC from sleep mode or LCD mode to brown out mode 19 JP20 5 0 VDC Circular connector for supplying the board with DC power Do not exceed 5 0 VDC at this connector 20 J7 IAP IAN 2 pin header connected to pins IAP and IAN on the IC 21 J6 VA 2 pin header connected to
103. t3 1 CE Raw mode MPU does not change CE values with creep or small current calcula tions bits 12 Send a message once per second for IEC 62056 217 Mode D on UART 1 at 2400 BAUD even parity The meter s serial number and current Wh display are sent as data UART 1 is routed to an IR LED if pos sible Mode D data fields are prefaced with OBIS codes in legacy format 0116 1 Auto calibration mode bit7 1 Enable Tamper Detect Do nothing spe cial Rev 4 0 N A Same units as CE s vOsqsum i 110 5 for 200 160 shunt with 8x preamp 884 0 A for 200 uQ shunt 442 0A for 400 HQ shunt 600 V for the 6541 REV 3 0 Demo Board 50 9A 30A sqrt 2 12096 32 32 16 16 Same units as CE s iOsqsum wrate mpu interval M temp call mtr call 0 3 mtr cal2 0 3 Center temperature T s_cal 1 v_cal 2 1 i cal 25 Error if exceeded Convert from CE counts to pulses The number of minutes of a de mand interval Expected number of cycles per second of mains 0 disables the software RTC run from mains Machine readable units per 0 1C Linear temperature calibration for meter elements A D Squared tempera ture calibration for meter elements A D Accumulation inter vals of Autocalibration Volts of Autocalibration Amps of Autocalibration 71M6541 Demo Board REV 3 0 User s Manual 407 3V 240V sqrt 2 120 3 2 Wh for 3 phase 1 0 Wh for 1 phas
104. tion Command Rix Select I O RAM location x 0x2000 offset is automatically added Rx Select internal SFR at address x Ra Read consecutive SFR registers in Decimal starting at ad dress a Ra Read consecutive registers in Hex starting at address a Ra n m Set values of consecutive registers to n and m starting at address a Example RI2 Read DIO RAM registers 2 3 and 4 in Hex The SFRs special function registers are located in internal RAM of the 80515 core starting at address 0x80 Commands for EEPROM Control Allows user to enable read from and write to EEPROM combinations Description Usage EE option arguments Command EECn EEPROM Access 1 Enable 0 Disable EERa b Read EEPROM at address a for b bytes EESabc xyz Write characters to buffer sets Write length EETa Transmit buffer to EEPROM at address a EEWa b z Write values to buffer CLS Saves calibration to EEPROM Example EEShello Writes hello to buffer then transmits buffer to EEPROM start EET 0210 ing at address 0x210 L Due to buffer size restrictions the maximum number of bytes handled by the EEPROM command is 0x40 Commands for Flash Memory Control Allows user to enable read from and write to Flash memory Comment Description Usage F option arguments Command FRa b Read Flash at address a for
105. tor e Thermal mass e Heat conduction away from the shunt thermal resistance towards the environment e Temperature coefficient of copper and resistive material It is quite obvious that the nominal resistance of the shunt resistor should be kept as low as possible Table 1 9 shows a few combinations of shunt resistance and 71M6X0X part number The parts with part numbers corre sponding to higher current capacity are designed to work with low shunt resistance Lowering the shunt re sistance below the recommended limits decreases accuracy and repeatability Good heat conduction can help to maintain the shunt temperature Attaching the shunt to solid metallic struc tures such as meter terminal blocks helps decreasing the thermal resistance This of course applies to meters where the terminals and other mechanical parts can be considered heat sinks i e they do not heat up due to other effects The thermal mass will control how long it takes the sensor to reach its maximum temperature Meters for which only short time maximum currents are applied can benefit from a large thermal mass since it will increase the time constant of the temperature rise The temperature coefficient TC of the shunt is a very important factor for the self heating effect Shunts with a TC of just a few PPM C can maintain good shunt accuracy even in the presence of significant self heating There are several methods that can be applied in the meter code that can
106. ture sensor STEMP of the 71M6X0X Remote Sensor Interface in a two byte hexadecimal format e g FFDF Negative readings are sig naled by the MSB being 1 T 22 C STEMP 0 337 STEMP 0 00015 C Example For STEMP OxFFDF the decimal equivalent is 32 The temperature calculates to 22 C 10 9 C 11 1 C Note that the IC temperature is averaged and displayed more accurately with the M1 command 1 10 7 BOOTLOADER FEATURE Demo Codes 5 4F and later are equipped with a bootloader feature This feature allows the loading of code via the serial interface USB connector CN1 when a Signum ADM 51 emulator or the Maxim Integrated TFP2 Flash Loader is not available 32 The bootloader functions as follows 1 Meter code must be modified in order to be loaded by the bootloader The meter code must start at address 0x0400 and its interrupt vector table must also start at 0x400 The bootloader itself is located at address 0x0000 and must be loaded into the IC by some method if the flash memory of the 71M6543 is empty or if code of a previous revision is loaded The bootloader is part of Demo Code 5 4F The bootloader loads Intel hex 86 files at 38 400 baud 8 bits no parity It will only accept record types 0 4 and 1 which are the types produced by Maxim Integrated s bank merge program or checksum program and the Keil compiler PK51 No records may overlap Keil bank merge and checksum produce this style of hex file by default
107. voltage and current signals to the meter It should be noted that the current flows through the shunts or CTs that are not part of the Demo Board The Demo Board rather receives the voltage output signals from the current sensor An optical pickup senses the pulses emitted by the meter and reports them to the calibrator Some calibration sys tems have electrical pickups The calibrator measures the time between the pulses and compares it to the ex pected time based on the meter Kh and the applied power 51 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual Optical Pickup for Pulses Figure 2 12 Meter with Calibration System Figure 2 13 shows the screen on the controlling PC for a typical Demo Board The error numbers are given in percent This means that for the measured Demo Board the sum of all errors resulting from tolerances of PCB components current sensors and 71M6541F tolerances was 3 4196 a range that can easily be compensated by calibration Figure 2 14 shows a load line obtained with a 71M6541 in differential mode As can be seen dynamic ranges of 2 000 1 for current can be achieved with good circuit design layout cabling and of course good current sen Sors li WinBoard Meter Testing Serial No 4738 Testing Functions Options FilefGraph Turbo Test r g o e 5 eo BE a NM Exit AlteF4 Cancel F2 StartF3 RepeatF8 AdjOpticF4 CreepF5 Mode F6 Skip FT View F3 Save F10 Station 1 Total Saved 0
108. with the Demo Code via the command line interface CLI The CLI allows all sorts of manipulations to the metering parameters access to the EEPROM selection of the dis played parameters changing calibration factors and many more operations Before evaluating the 71M6541 on the Demo Board users should get familiar with the commands and respons es of the CLI A complete description of the CLI is provided in section 1 8 1 10 Rev 4 0 71M6541 Demo Board REV 3 0 User s Manual 1 8 1 SERIAL COMMAND LANGUAGE The Demo Code residing in the flash memory of the 71M6541 provides a convenient way of examining and modifying key meter parameters via its command line interface CLI The tables in this chapter describe the commands in detail Commands for CE Data Access CE DATA ACCESS Comment Description Allows user to read from and write to CE data space Usage Starting CE Data Address option option Command A Read consecutive 16 bit words in Decimal starting at ad combinations dress A JASSS Read consecutive 16 bit words in Hex starting at address A JA n n Write consecutive memory values starting at address A Example 140 Reads CE data words 0x40 0x41 and 0x42 7E 1AD2 9A23 Writes two hexadecimal words starting 0x7E 102416384 Writes one decimal word starting 0x10 All CE data words are in 4 byte 32 bit format Typing JA will access the 32 bit word located at the byte a

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