Harsh Environment Acquisition Terminal (H.E.A.T.) System
Contents
1. 4 2 Upgrading Existing Installation When upgrading to a new version there is only one file that could be important to preserve between versions It is located in the program folder and is the TIDemo exe config file This file as you ll read later possibly contains calibration information regarding your actual hardware Other files can be simply copied over or removed and replaced with the updated software version SLVU468 June 2011 Software Installation 17 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 18 Software Installation SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 5 1 5 2 I Chapter 5 TEXAS SLVU468 June 2011 INSTRUMENTS Software Application Overview The HEATEVM demonstration screen Figure 5 1 illustrates what will be seen on the user terminal interface RE S Texas Instruments Demonstration S i 200 C Demonstration Board TEXAS This software along with the demonstration hardware highlights key devices from TI s 200C portfolio INSTRUMENTS No output file selected 0of4 MB Temp Min Temperature C Temp Max 3 58 107 29 107 29 45 a o x 45 Y Axis Z Axis o 08 28 20 08 28 30 08 28 40 08 28 50 08 29 00 Kaes Figure 5 1 HEATEVM Demonstration Screen Connect Disconnect The upper left most button is labeled Connect or Disconnect d2. channel 2 RS 232 setup SLVU468 June 2011 Submit Documentation Feedback 8 bits per xfer SPICLK SMHz SPICLK 5MHz SPICLK 2 5MHz SPICLK 1 25MHz SPICLK 0 625 MHz SPICLK 3125 KHz We are the master We drive the clock CLK Polarity 1 PHASE 1 Firmware Code Copyright 2011 Texas Instruments Incorporated 29 TA TEXAS INSTRUMENTS www ti com void setupSCI void f H allow peripheral config changes SCIICTL3 0 SCICCR 0x07 SCIICTL2 TXENA SCHCTL2 TXWAKE SCI1PC3 TX_FUNC ICLK 25MHz 57600 baud 0x0001 45 SCITHBAUD 0x00 SCIIMBAUD 0x01 SCIILB AUD 0x45 old values from weird clocks 38400 baud 00 00 1F 19200 baud 00 00 3F ICLK 20MHz SCILHBAUD 0x00 SCIIMBAUD 0x01 SCIILB AUD 0x58 changeme nominal 00 01 45 other day 00 01 58 double is 00 02 8A SCIICTL3 0 CLOCK TX_ACTION_ENA SCIICTL3 SW_NRESET NIM SPI Read reformat MMM read 24 bytes from SPI store in lt buf gt as HEX ASCII Comma replace last Comma with CR char read24SPI char buf static char szErr A DC Timeout r short iCtr iComma 3 char cFlag 0x00 char cSPI cHi cLo ps ps buf for iCtr 0 iCtr lt 24 iCtr f 30 Firmware Code SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated
3. endif NO_TIMEOUT return cRetVal l Copyright 2011 Texas Instruments Incorporated Firmware Code 33 34 Firmware Code SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated IA TEXAS INSTRUMENTS Appendix A SLVU468 June 2011 Establishing Tool Communication Via Terminal The tool data can be seen and interpreted directly without using the demonstration software Close all software that might be using the same port the electronics are connected to Start your terminal program with the following settings Table A 1 Configuration Connect using Installed COM Port tool is attached to Bits per second 576000 Data bits 8 Parity None Stop bits 1 Flow control None If the electronics are currently logging information its output should appear almost immediately ATI Interpreting Data Frames Data frames are visible while communicating with the tool in a terminal Terminal output example 9E58BE BD8D85 800071 BD07F2 C9D0CE 7FFDE9 80005C 80006C The frame is a series of numeric values in hexadecimal format separated by commas The values represent A D counts Converting these A D counts into sensor data requires calibration as described above Accessing the data in this manner removes any limitations on interpretation Terminal error output example Error message here Any data frame that starts with an exclamat
4. 1 TEXAS INSTRUMENTS www ti com wait for A DC DRDY while SPI1PC2 amp SCS_DIN SCH DIN j H check for overrun cFlag timerC heck if cFlag 0x00 break send 8 bits on the SPI channel SPIIDATO iCtr wait for 8 bits received on SPI channel while SPI1CTRL3 amp RX INT FLAG 0 f cFlag timerC heck if cFlag 0x00 break j did we timeout if cFlag 0x00 f H no save this byte as HEX ASCII cSPI 0 SPIIBUF cSPI SPIIBUF Z if iComma 3 cSPI SPIIBUF 0x80 00 to FF not 2 s complement else cSPI SPIIBUF no change bytes 2 and 3 cHi cSPI amp 0xF0 gt gt 4 if cHi gt 0x09 cHi 0x37 else cHi 0x30 cLo cSPI amp OxOF if cLo gt 0x09 cLo 0x37 else cLo 0x30 ps cHi pst cLo if aComma 0 iComma 3 on the last character make EOL not Comma if iCtr 23 ps 0x0D else pst ps 0 else yes timeout asserted say Timeout iCtr 0 SLVU468 June 2011 Firmware Code 31 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated TA TEXAS INSTRUMENTS www ti com ps szErr while ps 0 buf iCtr pst buf iCtr ps break return cFlag MILL timer routines MILL wait until we are on an 20ms boundary uses the RTICNTR top 21 bits upcounte
5. 0MHz PCR CLKDIV 3 ICLK SYSCLK 3 20 0MH A PCR CLKDIV 2 ICLK SYSCLK 2 30 0MHz A PCR RTI CTRL PCR PENABLE Enable peripherals ifdef LCD_EXISTS HETDIR OxFFFFFFFF HETx Output direction HETDOUT 0x00000000 init Icd light on put_cursor 0 0 put_text Ready endif LCD_EXISTS 26 Firmware Code SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS www ti com setup A DC drive clock not necessary if using buffered resonator output setupECP setup the SPI channel setupSPI setup the RS 232 SCI setupSCl Loop getting A DC sending to RS 232 for 33 D t SLVU468 June 2011 Submit Documentation Feedback oscilloscope trigger high GIODOUTA X0 align on 8msec Time hack timerAlign cBrk 0x00 begin synchronizing pulse AIDC SYNCN LO Synchronize SPI1PC3 amp ENA DOUT 34uSec hang time for SYNC pulse wait for 0 to 1 transition on 20 bit upcounter 0x800 iTime RTICNTR amp 0x00001 000 iTime 0x00001000 while RTICNTR amp 0x00001000 iTime for iDelay 0 iDelay lt 8 iDelay H J AIDC SYNCN HI allow resampling SPI1PC3 ENA_DOUT end synchronizing pulse oscilloscope trigger low GIODOUT A amp X0 wait for
6. A DC to read a new sample while SPILPC2 amp SCS_DIN SCS_DIN check for overrun cBrk timerCheck if cBrk 0x00 break J oscilloscope trigger high GIODOUTA X0 Firmware Code 27 Copyright 2011 Texas Instruments Incorporated TA TEXAS INSTRUMENTS www ti com read 24 bytes from A DC cBrk read24SPI amp szASCbuf 0 send output string to RS 232 24 x 2 digit chars 48 8 commas CR 1 total 57 ps amp szASCbuf 0 for iCtr 0 iCtr lt 57 iCtr might be timeout string if ps 0 break RS 232 out SCIITXBUF ps RS 232 finished transmitting while SCIICTL2 amp TXRDY 0 f t 56 Hex ASCII chars plus CR for iDelay 0 iDelay lt 8 iDelay ifdef LCD_EXISTS szASCbuf 6 char 0x00 put_cursor 0 0 put_text szASCbuf endif LCD EXISTS while forever main CLKOUT A DC oscillator drive setup A CLKOUT appears on pin 48 of the 84 pin device void setupECP void spnu202b pdf ECP Ref for TMS470R1 A ECPCTRL amp ECPEN undo enable CLKCNTL CLKDIR CLKSR_ICLK CLKCNTL 0x20 with ICLK at 20MHz ECPCTRL ECPCOS 0x03 ECPCOS is ON divide by 4 default 5 0OMHz ECPCTRL ECPCOS 0x07 ECPCOS is ON divide by 8 default 2 5MHz ECPCTRL ECPCOS 0x0F ECPCOS is ON divide by 16 1 25MHz ECPCTRL ECPCOS 0x
7. Most capacitor types have falling capacitance values and increasing IR values as the ambient temperature increases which present trade offs when working with capacitors at elevated temperatures The HEATEVM uses a nominal number of capacitors and value of capacitance To reduce temperature effects 200 C EIA rated capacitors have been used The COG dielectric has a flat temperature coefficient over temperature and are also reffered to as NPO negative positive zero referring to its value change over temperature These COG NPO capacitors are used as decoupling capacitors while 200 C rated tantalum capacitors are used to reduce power supply ripple to the circuit board To reduce ripple on the voltage reference a 1uF stacked capacitor was used to maintain fast transient response to reduce noise 2 2 Derating of Integrated Circuits and Passive Components When designing high temperature circuits engineers normally derate the electronic components from the manufacturer s specifications This is particularly true for the voltage rating of capacitors and the power rating of resistors As more manufacturers produce electronic components rated for operation at elevated temperatures and engineers gain experience working with these compoenents the act of derating will become less important In any case the overall rating of an electronic circuit will always be less than the rating of the weakest component in the circuit Virtually every high temperature
8. Software Installation 2ou zeg eege eege gede geed sedleslee gege eege eege REES deg eege 17 4 1 First Time Installation 17 4 2 Upgrading Existing Installation sise SEENEN NNEKNANEENEN ANER AN NEEN SKS NEEN ae 5 Software Application Overview 19 5 1 GONNECt 7 DISCONMECE 238 umrensesnsmeentommennanmesnmesmnenerenneeneaneean penses disons E 19 5 2 OUIDUR ARS OR PR ee 19 5 3 Status E 20 5 4 Temperature Data NENNEN EN NENNEN ENEE NENNEN REENEN NEE ENKER E SESE 20 5 5 Axis Data Eine Giants E 20 5 6 Four Miscellaneous A D Channels Not Visible on GUI eee eee teen eee eens eeeeeeeeeeeeaeeee 20 6 Qutp t e ET 21 7 Calibration ss NASH eSNeN NEE EENS bers cows RSENE einen ni ENEE da EENSNSEES REENEN ANEN Neen 23 8 Firmware e EE 25 A Establishing Tool Communication Via Terminal eceeeeeeeeee eee ee eens eee eens sees eeeeeenees 35 A 1 Interpreting Data Frames 35 B Hexadecimal ugeet de ESA agen OE dee ENEE CEA eme dE ge S 37 SLVU468 June 2011 Contents 3 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated A IA TEXAS INSTRUMENTS www ti com List of Figures Tt HEATEVM Block Diagramme KREE NEEN NNN ENKE NNN KREE EN SETAS ENNER NEEN KR KENNEN Ne REN ENEE T 3 1 HEATEVM ARM7 ADC CGommuntcatons nnna 11 3 2 Inclination Block Diagram EE 13 5 1 HEATEVM Demonstration Green 19 List of Tables Ai eut LU LEE e E 35 A 2 Data Frame Example Breakdown EN 35 List of Figur
9. an ADCLK signal from its ECLK pin 80 ECLK is software programmable and in the source code included in this manual ECLK is set to 1 25MHz There is no software setup between the ARM7 and the ADS1278 HT as the setup options on the ADS1278 HT set up are defined by the user s choice of format and mode options with the channel enable pins The HEATEVM is shipped with preset format pin options on the ADS1278 HT as Format 001 which are set by soldered jumpers on PJ10 and establishes a Time Division Multiplexed bit steam With this format the position of each 24 bit ADC reading is fixed in time such that disabling any channel results in a 000000H reading for that channel and all the ADS1278 HT readings are serial out on pin DOUT1 If the user desires to change the format from this default setting high temperature solder should be used Each of the eight ADS1278 HT channels are enabled by default To change the default channel enables solder jumpers at JP12 Each jumper pair is tied to each PWDN channel enable pins 45 to 52 The ADS1278 has 4 mode options which can be set by the user by jumpers on JP11 The default setting is Mode 11 for low speed The power supply rails have been separated since the power up sequence differs between the ADC and ARM7 devices SLVU468 June 2011 Hardware Setup 11 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated I TEXAS INSTRUMENTS Power Up Requirements Sequence www ti
10. application is also a high reliability application For example in high reliability applications using all electronic components rated to 200 C and 1 000 operating hours an overall derating of the electronic circuit could be as high as 50 C SLVU468 June 2011 System Design Guidelines 9 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 10 A TEXAS INSTRUMENTS Derating of Integrated Circuits and Passive Components www ti com Despite the advancement of computer generated life prediction models most manufacturers of high temperature control systems require hard numbers in perfroming acclerated life testing such as HALT Highly Accelerated Life Tests to find weak links in the design and or manufacturing process By starting with manufacturer qualified high temperature electronic components the design engineer will enjoy a higher percentage of successful HALT testing of new products Perhaps just as important is knowing that the high temperature electronic component manufacture will continue to support a high temperature rating though design cycles which within the electronic industry are normally much shorter than the high temperature high reliability product being designed For example an aircraft engine control system can be in production for extened product life cycles between 20 to 30 years while an electronic component may see a new design cycle every 6 to 10 years For high temperature operation re
11. of six channels dedicated for temperature pressure and accelerometers The OPA211 HT enables accelerometer inputs and all three axis inputs have a buffer amplifier with two poles in a 20 Hz Butterworth filter Temperature sensing is performed with the THS4521 HT and OPA2333 HT devices For pressure sensing a high impedance bridge instrumentation amplifier is used from the THS4521 HT and the OPA2333 HT devices This circuit realizes a high gain and is ideal for measuring pressure in harsh environment applications such as down hole drilling HEATEVM also has dedicated INA333 HT inputs for pressure transducer coupling SN65HVD233 HT CAN Transceiver O Temperature Ch4 Pressure Position O Speed Flow Resistivity Rock Density e chs ADS1278 HT SM470R1B1M HT 8 Ch ADC ARM 7 Micro SN65HVD11 HT 485 Transceiver REF5025 HT 2 5 V Ref O HS4521 H O Figure 1 1 HEATEVM Block Diagram The platform is suited for interfacing with external sensors The user is expected to interface these sensors by means of user generated cabling The HEATEVM is pre loaded with basic firmware layer for the ARM7 microcontroller and source code is provided in this User Manual The data acquired by the system can be extracted by the HEATEVM graphical user interface GUI software The GUI performs SLVU468 June 2011 Overview 7 Submit Documentation Feedback Copyright 2011 Texas I
12. resistor pairs R54 R53 and R56 R55 A small differential RC filter is in between the outputs of IC14 and the ADS1278 SLVU468 June 2011 Hardware Setup 15 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 16 Hardware Setup SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated P Chapter 4 IA TEXAS SLVU468 June 2011 INSTRUMENTS Software Installation The software installation for the HEATEVM system is broken into two sections First Time Installation and Upgrading Existing Installation 4 1 First Time Installation The software installation has several prerequisites that may or may not be already installed on your PC If the software is already installed you can safely proceed to the next step Prerequisites 1 Microsoft NET Framework 3 5 sp1 http Awww microsoft com downloads en details aspx Familyld 333325fd ae52 4e35 b531 508d977d32a6 2 Microsoft Charting This can be found in the in the 3rd Party folder of the program files MSChart exe OR Download from http Awww microsoft com downloads en details aspx Familyld 130F7986 BF49 4FE5 9CA8 910AE6EA442C Installation 1 Install Microsoft NET Framework 3 5 sp1 and follow instructions 2 Install Microsoft Charting and follow instructions 3 Copy the program folder onto the local computer The software can run from the desktop or can be placed in Program Files along with other software
13. supplied as the on board voltage reference The REF5025 HT has a nominal voltage of 2 5 V The on board voltage reference can be replaced by placing a jumper between pins 2 and 3 of JP5 and applying a new external voltage to JP6 with pin 1 as GND and pin 2 as the positive voltage SM470R1B1M HT Connection Options The TI ARM7 is in circuit programmable using either the 20 pin JP20 or the 14 pin JP19 Because the demonstration board can be heated to 200 C a standard gold plated pin header is used in both cases The user must check the pin orientation against the circuit layout Looking at the circuit board with the ARM7 chip toward the user s left hand pin 1 on JP20 and JP19 is on the top left side of each pin header ADS1278 HT Analog Inputs The ADS1278 HT has eight differential inputs to its eight parallel 24 bit analog to digital converters The HEATEVM provides input to all eight channels using the analog circuits described below Channels 1 2 and 3 Inclination Circuits Measuring inclination or tilt is a common measurement in the harsh environment down hole drilling industry For example most drilling tools measure 3 axis inclination to determine what the orientation of the drill bit is The first 3 channels of the ADS1278 HT are examples of a filtered buffer amplifier for use in measuring the 3 axis inclination signals The HEATEVM inclination signals are filtered in an active two pole Butterworth filter using the using the OPA211
14. the data frame being sent from the electronics or if the electronics themselves report an error 1 Electronics error if the analog to digital circuit is not responding to the processor it will flash in red IADC communication failure 2 Communications error if the software is unable to interpret the data frame Cannot parse Index value There are log files saved with non critical exceptions but can be useful in identifying issues Temperature Data Low max and current temperatures are displayed here These are reported from a built in RTD on the board See calibration section on how to calibrate the values Axis Data Line Charts The initial demonstration of the Demo Board is to have an accelerometer transmitting data from all three axes X Y Z These values are demonstrated here in degrees See calibration section for how to calibrate the values Four Miscellaneous A D Channels Not Visible on GUI There are four additional channels in the eight channel A D converter that are not displayed but are still recorded in the output file These values do not have a calibration applied to them but the data is accessible via Excel or other comma separated values csv software See the section on the output file Software Application Overview SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated Chapter 6 ho OMENS SLVU468 June 2011 Output File The output file conta
15. 0F ECPCOS is ON divide by 16 1 25MHz ECPCTRL ECPCOS 0x1F ECPCOS is ON divide by 32 633KHz A ECPCTRL ECPCOS 0x3F ECPCOS is ON divide by 64 ECPCTRL ECPCOS 0x7F ECPCOS is ON divide by 128 28 Firmware Code SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS www ti com ECPCTRL ECPEN f SPI setup A A DC 1278 HT DOUT changes on falling SCLK Therefore TMS470 should use Polarity 1 Phase 0 mode SPI EN gt GPIO In lt DRDY gt SPI CS gt GPIO Out lt scope trigger gt void setupSPI void SPIICTRL1 0 CHARLEN 8 1 SYSCLK 40MHz ICLK 20MHz SPIICTRL1 PRESCALE 2 A SPIICTRLI PRESCALE 4 SPIICTRLI PRESCALE 8 A SPIICTRLI PRESCALE 16 if SPIICTRLI PRESCALE 32 A SPIICTRLI PRESCALE 64 swapping SPI CS and SPI EN setup CS for A DC SYNCN sync SPIIPC1 ENA DIR default EN is set already for input SPI1PCI amp SCS_DIR SPILCTRL2 MASTER SPILCTRL2 CLKMOD SPIICTRE2 POLARITY SPILCTRL2 PHASE SPIIPC6 CLK_FUN SPIIPC6 SIMO FUN SPIIPC6 SOMI FUN Sync ing input from SPIENA 4 pin mode iI SPIICTRL3 ENABLE HIGHZ enable SPIICTRL2 SPIEN PortA 0 add a FLAG output to assert SYNC Convert GIODIRA 0 X0 Dy GIODIRD 0 X4 PortD 5 adda READY sensor input GIODIRD amp X5
16. 3 95 With a base layer PCB thickness of 0 093 inches the 8 layer HEATEVM has a reasonable amount of stiffness to reduce strain on solder joints For prolonged 210 C elevated testing periods the polyimide PCB needs to be kept dry and best results are obtained when testing is conducted inside a dry pressure chamber In general this is the case with many harsh environment high temperature drilling and logging tools The surface copper traces and pads are protected with a nickel gold finish The nickel isolates the gold from the copper while the gold provides for good solder bonding This type of system prevents the tin found in most solders from forming intermetalic bronze with the copper traces For short term exposure at elevated temperatures or temperatures below 98 C the nickel gold finish may not be required however this added margin safeguards against the intermetaic bronz formations 2 1 2 Layout Guidelines and Recommendations Power and ground plains are suggested for optimizing the performance of the ADS1278 Decoupling capacitance should be physically placed as close as possible to the power pins of the ADS1278 and the SN470R1B1M HT ARM7 microcontroller to minimize capacitance and gain optimized performance The location of these decoupling capacitors becomes even more critical in high temperature operations since in addition to the higher costs larger valued capacitors become the life limiting component in many high temperature systems
17. HT Low Pass filters of 20 Hz to reduce 60 Hz noise picked up by the cable running between the HEATEVM inside an oven and the inclination sensor board located outside of the oven When the cable is not connected a precision resistor network provided a fixed DC voltage to the three inclination inputs on the HEATEVM This allows operation without the inclination circuit An RTD circuit can be added to the HEATEVM to provide a differential signal to the THS4521 HT and will need to use the REF5025 HT to bias the circuit The OPA211 HT can be used to buffer the REF5025 HT to the circuit The REF5025 HT will also provide the reference voltage to the ADS1278 HT Figure 3 2 illustrates the block diagram of the inclination circuits oO ng 5 0V DC from tool CC D gt Tool 5 0V DC EH 1 Pole 5Hz 2 Pole 20 Hz ees ga S g Filter Koc Filter OPA211 HT TT i MEMs 3 Axis 3G tpt i Accel amp Tilt ADS1278 Sensor H Analog Devices ml f j 1 Pole 5Hz 2 Pole 20 Hz Los Fa e Filter CL Filter OPA211 HT KH ADXL330 ee ai vee Koc Filter OPAZIL HT ke gt HT i Buffer for P Zero G Ref V S ees gt RC Filter ps EEN w REF5025 TH Ke UE Twisted Pairs ina 200C cable Figure 3 2 Inclination Block Diagram 3 5 2 Channel 4 Simple Amplifier Using the OPA211 HT A simple amplifier c
18. Harsh Environment Acquisition Terminal H E A T System EVM User s Guide User s Guide di TEXAS INSTRUMENTS Literature Number SLVU468 June 2011 SLVU468 June 2011 f Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated IJ TEXAS INSTRUMENTS Contents OVO VIOW ee EEN ee 7 2 System Design Guidelines 9 2 1 PGB Details sssscmmanmmsssenss semence cus ete SS ewe sweet cans EEN EENS ONS ce ceed vende ENN EEN cee 9 SL PCB Materials ss cscs gege geu gea EES SSES dee SEENEN 9 2 1 2 Layout Guidelines and Recommendations 9 2 2 Derating of Integrated Circuits and Passive Components cceeeeeee eee eee ence eee ee seen sees eee eeeeeeeeeeeeeeeeee 9 3 Hardware Setup WE 11 3 1 Power Up Requirements Sequence EE 12 3 2 ADS1278 HT Connection Options ege cen EENS ENEE NEE EEN EE ENEE REENEN EEN ENEE ene sesp eee 12 3 3 Voltage Reference saviicvicnciwannucwanevenanenen vena NENNEN ENNEN oe NENNEN ENK NEEN ENKEN ENNEN ENK EEN EH wave ENKEN vannes 13 3 4 SM470R1B1M HT Connection Options AEN 13 3 5 ADSTt278 HT Analog IMPUS E 13 3 5 1 Channels 1 2 and 3 Inclination Circuits NENNEN 13 3 5 2 Channel 4 Simple Amplifier Using the OPA211 HT e 13 35 3 Channels RTD DEE 14 8 5 4 Channel 6 INA333 HT Instrumentation Amplifier AN 15 3 5 5 Channel 7 THS4521 HT Differential Amplifier eee eee e ee eee eee eeeeeeeeeeeeeeneee 15 3 5 6 Channel 8 Discrete Differential Amplifier Circuit AN 15 4
19. P Products DSP Clocks and Timers Interface Logic Power Mgmt Microcontrollers RFID RF IF and ZigBee Solutions www ti com audio amplifier ti com dataconverter ti com www dip com www ti com clocks interface ti com logic ti com power ti com microcontroller ti com www ti rfid com www ti com lprf Applications Communications and Telecom Computers and Peripherals Consumer Electronics Energy and Lighting Industrial Medical Security Space Avionics and Defense Transportation and Automotive Video and Imaging Wireless TI E2E Community Home Page www ti com communications www ti com computers www ti com consumer apps www ti com energy www ti com industrial www ti com medical www ti com security www ti com space avionics defense www ti com automotive www ti com video www ti com wireless apps Mailing Address Texas Instruments Post Office Box 655303 Dallas Texas 75265 Copyright 2011 Texas Instruments Incorporated
20. com 3 1 Power Up Requirements Sequence The HEATEVM has split power inputs supporting the ARM7 and the ADS1278 HT Both the ARM7 and the ADS1278 HT have 3 3V IO and 1 8V core voltages Splitting the supply inputs allows for differing power up sequences for each chip All voltages reference a common ground The GND is tied to a ground plane located on layer 2 of the PCB The ARM7 power input and its reset PORRSTN pin 68 of the ARM7 is on JP24 The SM470R1B1M HT document SPNS155C requires that the 3 3V IO voltage is greater than 1 1V before the 1 8V core voltage is greater than 0 6V Specific timing requirements for the PORRSTN input are also outlined in SPNS155C Pin 1 on JP24 has a square pad JP24 Pin 1 3 3V This is the VIO for the ARM7 JP24 Pin 2 GND JP24 Pin 3 PORRSTN This is the power on or off reset for the ARM7 JP24 Pin 4 1 8V This is the ARM7 core voltage JP24 Pin 5 GND The power input for the ADS1278 is on JP2 The 5V supply needed by the analog input circuits and the ADS1278 HT analog voltage AVDD is on JP25 For detailed information on the power up sequence of the ADS1278 HT see SBAS447B In general core voltage should reach a nominal 1V before the IO voltage reaches 1V The analog voltage must be last with a nominal 3 Volts triggering an internal reset to the chip Note the power up sequence is different than the ARM7 so tying supply inputs together is not recommended Pin 1 on JP2 has a square pad JP2 Pin 1 3 3V Th
21. current for a 1000 Q RTD The reference voltage is 2 5 V This voltage is buffered IC7 OPA2333 B with a resistor divider network of R25 and R26 The resistor divider is used to reduce the reference voltage to 0 45 V This voltage is used to create a DC bias to the positive input to INA of IC7 Hardware Setup SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS www ti com ADS1278 HT Analog Inputs The A amplifier of IC7 OPA2333 HT has the 1000 Q RTD in its feedback This amplifier holds the voltage across R24 to the bias value of 0 45 V This sets the current in the feedback RTD resistor to laor 0 45 R24 As R24 is a fixed high precision resistor equal to 1000 Q Ikpr 0 0045 A and the voltage across the RTD at 0 C is 0 45 V As the temperature increases the voltage across the RTD increases at 0 0173 V C IC8 THS4521 is used to amplify the differential signal across the RTD The gain of IC8 is fixed by R19 R18 R20 R21 3 09 At 0 C the differential output is 3 09 x 0 45 1 39 V The output is then 0 0535 V C The differential amplifier IC8 THS4521 HT has its VOCM pin either as an open circuit or tied back to the ADS1278 VCOM pin using jumper block JP9 In the case of the RTD circuit a zero temperature creates a differential voltage of 0 45 V so an offset is accounted for in the display software 3 5 4 Channel 6 INA333 HT Instrumentat
22. epending on whether or not you re currently connected and receiving data from the electronics The HEATEVM uses serial port COM communication This is frequently provided by USB to Serial connectors in recent computers If the computer has only a single COM port installed the Connect button will automatically try to connect to that port If there are more than one COM port available a window will pop up allowing you to choose which COM port is connected to the TI Demo hardware Output Stop This button is labeled Output or Stop depending on whether or not the real time data is being saved to a file The output button allows the saving of the real time data into a file By selecting the output file all data from that point begins to be saved Data that was received prior to setting an output file is not retroactively saved SLVU468 June 2011 Software Application Overview 19 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS Status Label www ti com 5 3 5 4 5 5 5 6 20 Status Label The file name label below and to the right of the Output button is a status label here it shows O of 4 MB When saving data to an output file this counter will demonstrate how much raw binary data is being saved This correlates to the future version of a memory demonstration where the 200 C memory will be 4 MB It will also report errors if it cannot successfully interpret
23. es SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated This document outlines the basic steps and functions that are required to ensure proper operation of the Harsh Environment Acquisition Terminal H E A T system evaluation module EVM kit The HEATEVM is a high temperature development platform that provides a complete signal acquisition system for operating temperature environments of 200 C All of the high temperature semiconductor devices are qualified and characterized from 55 C to 210 C operation for 1 000 hour operating life thus eliminating the need for expensive up screening components or using commercial products who s temperature range falls outside the datasheet specifications SLVU468 June 2011 List of Tables Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 5 6 List of Tables Copyright 2011 Texas Instruments Incorporated SLVU468 June 2011 Submit Documentation Feedback e Chapter 1 IA TEXAS SLVU468 June 2011 INSTRUMENTS Overview HEATEVM platform contains a signal chain consisting of an eight channel analog input which conditions digitizes and processes all of these signals The EVM has six channels dedicated for temperature pressure and accelerometers and two are general purpose channels i e fully differential and single ended Figure 1 1 shows the HEATEVM block diagram The analog inputs channels are comprised
24. ig Open this file with a text editor such as Notepad and you ll see something similar to below lt xml version 1 0 encoding utf 8 gt lt configuration gt lt appSettings gt lt To fake serial data for GUI testing make the value Fake below gt lt add key COMPort value Fake gt lt To allow the chart axis to show all possible values 24bit int rather than the axis 90 degrees set value True below gt lt add key FullRange value False gt lt Temp Coefficients Match Cal Function y x a x b gt lt add key TempCoeff1 value 0 0000357632473028550992430112654229 gt lt add key TempCoeff2 value 0 gt lt Axis Coefficients Match Cal Function y x a x b gt lt add key AxisCoeff1 value 0 0000107288360595703125 gt lt add key AxisCoeff2 value 0 gt lt appSettings gt lt configuration gt The TempCoeff1 and TempCoeff2 correspond to the a and b variables of the point slope function y x a x x b respectively When the AD counts x are evaluated the result is the RTD s temperature The AxisCoeff1 and AxisCoeff2 do the same thing for the axes calibration into degrees By changing Coeff1 value to 1 and Coeff2 value to 0 for both Temp and Axis the resulting output will be the raw AD data just like the other 4 channels which have no calibrations applied If this is done or any calibration applied that would result in a range greater
25. ins time data 4 calibrated channels and 4 non calibrated channels in a comma separated file The 4 calibrated correspond to the 4 displayed data in the software temperature x axis y axis and z axis TI 200C Demonstration Output File Below is a CSV file of the data seen while Recording started 4 19 2011 8 55 02 AM running the demonstration Time Temp F X Axis Y Axis Z Axis AD4 AD6 AD7 AD8 55702 70 185 97 79 27 34 21 78 29 8388608 8388608 8388608 8388608 55 02 90 189 55 78 2 33 14 79 36 8388608 8388608 8388608 8388608 55 03 20 193 12 77 13 32 06 80 44 8388608 8388608 8388608 8388608 The other four channels can be raw data as well if the calibration is changed to pass through the value rather than modifying it See calibration section The four non calibrated channels cannot be calibrated via the demonstration software SLVU468 June 2011 Output File 21 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 22 Output File SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated e Chapter 7 ho OMENS SLVU468 June 2011 Calibration Calibration applies coefficients and functions to obtain an accurate representation of a sensor s measurement To do this to the analog to digital converter the coefficients can be entered into a text file prior to running the software Within the program s folders there is a file TIDemo exe conf
26. ion Amplifier Channel 6 of the ADS1278 HT is setup as a differential channel and is a user illustrated circuit based on the INA333 HT and pins 6 and 5 of JP26 R42 is used to set the gain value of the INA333 HT The gain is calculated by Gain 1 1000K R42 for R42 400 O the gain is 251 A simple RC filter is placed between the amplifier and the ADS1278 Test point PT10 is available to monitor the amplifiers output 3 5 5 Channel 7 THS4521 HT Differential Amplifier Channel 6 of the ADS1278 HT is setup as a differential channel and a differential amplifier circuit for user input signals based on the THS4521 HT Full access to the THS4521 input pins are available at JP26 pins 1 4 The amplifier has a fix gain of 1 set by R47 R48 and R51 R52 This amplifier is operating from the 3 3 V supply 3 5 6 Channel 8 Discrete Differential Amplifier Circuit Channel 8 of the ADS1278 HT is setup as a differential channel and is left for the users discretion It can be used for simulating the measurement of a standard 4 wire bridge type pressure transducer In this case the pressure transducer cable would be connected to JP8 IC10 OPA211 HT is used to bias the bridge circuit to 2 5 V The bridge differential voltage is input is buffered by 1C11 OPA2333 HT The OPA2333 HT is precision amplifier well suited for this type of application 1C14 THS4521 HT is used to amplify the buffered signals coming from 1C11 The gain of this circuit is 251 set by the
27. ion point is an error frame and the cause of the error is contained in the text following it Table A 2 Data Frame Example Breakdown 9E58BE BD8D85 800071 BD07F2 C9D0CE 7FFDE9 80005C 80006C 9E58BE 24 bit channel x axis BD8D85 24 bit channel x axis 800071 24 bit channel x axis BDO7F2 24 bit channel spare C9DOCE 24 bit channel temperature 7FFDE9 24 bit channel spare 80005C 24 bit channel spare 80006C 24 bit channel spare SLVU468 June 2011 Establishing Tool Communication Via Terminal 35 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 36 Establishing Tool Communication Via Terminal SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated IA TEXAS INSTRUMENTS Appendix B SLVU468 June 2011 Hexadecimal Hexadecimal is the number format output by the electronics For quick reference hexadecimal base 16 is counted as follows with decimal base 10 Decimal Base 10 012345678910 11 12 1314 15 16 17 18 19 20 24 25 26 27 0 1 2 3 4 5 6 7 8 9 A B c D E F 10 11 12 13 14 18 19 1A 1B Hexadecimal Base 16 SLVU468 June 2011 Hexadecimal 37 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries Tl reserve the right to make corrections modifications enhancements improvements a
28. ircuit using the OPA211 HT with a fixed gain of 10 The user can supply an input signal to pin 7 of JP26 The amplifier has a 1 25 V reference at the in pin PT8 is a test point for monitoring the amplifiers output SLVU468 June 2011 Hardware Setup 13 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated I TEXAS INSTRUMENTS ADS1278 HT Analog Inputs www ti com 3 5 3 Channel 5 RTD 14 Channel 5 of the ADS1278 HT is setup to measure board temperature using an onboard 1000 Q RTD located at JP8 An external RTD can be used by removing the onboard RTD and the two jumpers on JP8 and replacing them with the standard 4 wire RTD In Well Logging systems it is typical to detect relative temperature changes of 0 001 C so the 24 bit accuracy associated with the ADS1278 HT is necessary in order to facilitate this measurement The RTD has a nearly flat response of 3 850 C starting with a nominal 1000 Q at 0 C At 20 C room temperature the RTD is 1077 Q and 1385 Q at 100 C The use of 3 85 Q per degree will create 1 2 C error at 200 C Use of a typical second degree polynomial curve fit will improve this measurement while also correcting for small circuit offsets However for demonstration purposes these small errors are negligible for a board mounted sensor and no system calibration unique to each board was per formed The RTD measurement circuit uses the voltage reference IC6 REF5025 HT to create a bias
29. is is the VIO for the ADS1278 HT JP2 Pin 2 GND JP2 Pin 3 NC JP2 Pin 4 1 8V This is the core voltage for the ADS1278 JP2 Pin 5 GND Pin 1 on JP25 has a square pad JP25 Pin 1 5V Analog voltage JP25 Pin 2 GND 3 2 ADS1278 HT Connection Options The ADS1278 HT has a several pin assigned options To provide the user with maximum flexibility the following jumper blocks connected to the following pin assignment pins of the ADS1278 HT In all cases a jumper installed results in a low setting e JP10 pins set the AD Format Options e JP11 pins set the AD Mode Options e JP12 pins enable the AD Channels For running the demonstration board at 200 C some jumpers are hardwired The user can change these setting by removing or adding a solders jumper These jumpers are of the same board layout as the other jumper blocks as such all the hardwired jumpers can be replaced with jumper blocks if so desired e JP13 is jumper to set CLKDIV to low input e JP16 are jumpers to interface the ADS1278 to SM470R1B1M ARM7 The ADS1278 is connecting to the ARM7 as a SPI device e JP1 is a hardwire to select running the ADS1278 pin 37 CLK from either the ARM7 pin 80 ECLK or the system 7 5 MHz clock 12 Hardware Setup SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated l TEXAS INSTRUMENTS www ti com Voltage Reference 3 3 3 4 3 5 3 5 1 Voltage Reference The REF5025 HT is
30. lb1m_bit_definitions h include Icd h comment the following line if program for TOOL decomment for DEVKIT board define LCD_EXISTS 1 comment the following line ifno timeout wanted for testing transmit define NO TIMEOUT 1 280 mSec outer loop define TIMER MAXVAL 0x00800000 17 6 mSec outer loop define TIMER MAXVAL 0x00080000 2 outer loop define TIMER MAXVAL 0x00400000 SLVU468 June 2011 Firmware Code 25 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated I TEXAS INSTRUMENTS www ti com void setupECP void A CLKOUT A DC oscillator drive setup void setupSPI void SPI setup void setupSCI void RS 232 setup char read24SPI char buf void timerAlign void wait for 8msec boundary char timerCheck void 8msec passed 0x00 less than OxFF more than void main void char szASCbuf 64 ps char cBrk 0x00 int iTime iDelay short iCtr 0 ifdef LCD_EXISTS int x_pos 0 cd display int x_pos_old 0 endif LCD_EXISTS the following values are based on 7 5MHz oscillator SYSCLK 8 x fOSC 60 0MHz GCR amp ZPLL_MULT4 GCR amp ZPLL_CLK_DIV_PREI GCR amp ZPLL_CLK_DIV_PRE2 GCR amp ZPLL_CLK_DIV_PRE3 A GCR ZPLL CLK DIV PRE 1 A GCR ZPLL CLK DIV PRE 4 A PCR CLKDIV 16 ICLK SYSCLK 16 3 75MHZ A PCR CLKDIV 8 ICLK SYSCLK 8 7 50MHz 7 PCR CLKDIV 4 ICLK SYSCLK 4 15
31. nd other changes to its products and services at any time and to discontinue any product or service without notice Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete All products are sold subject to Tl s terms and conditions of sale supplied at the time of order acknowledgment TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with Tl s standard warranty Testing and other quality control techniques are used to the extent Tl deems necessary to support this warranty Except where mandated by government requirements testing of all parameters of each product is not necessarily performed TI assumes no liability for applications assistance or customer product design Customers are responsible for their products and applications using TI components To minimize the risks associated with customer products and applications customers should provide adequate design and operating safeguards TI does not warrant or represent that any license either express or implied is granted under any TI patent right copyright mask work right or other TI intellectual property right relating to any combination machine or process in which TI products or services are used Information published by TI regarding third party products or services does not constitute a license from TI to use such products or services or a
32. nstruments Incorporated I TEXAS INSTRUMENTS www ti com auto scrolling of data provides a temperature display illustrates actual minimum and maximum values and provides data logging capability for all eight channels This GUI software is optional and the user can program their own firmware into the ARM7 microcontroller by means of the JTAG port on the HEATEVM The optional software runs on a PC terminal and proper serial interfacing is required The optional software is available for downloading through http focus ti com docs toolsw folders print heatevm htm The HEATEVM kit includes one EVM board All power supply requirements sequencing need to be provided externally and are outlined in the Power Up Requirements Sequencing section 3 1 of this manual Please refer to the HEATEVM schematic Gerber and BOM files for component use and their locations and references from this user guide The schematics gerbers and BOM files are available at http focus ti com docs toolsw folders print heatevm html Overview SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated e Chapter 2 IA TEXAS SLVU468 June 2011 INSTRUMENTS System Design Guidelines 2 1 PCB Details The PCB in the HEATEVM is built from P95 polyimide material and has very good mechanical stability up to temperatures in excess of 210 C 2 1 1 PCB Materials The dielectric constant of the polymide varies between 3 74 and
33. r assume 7 5MHz oscillator PLL multiple of 8 60MHz SYSCLK 11 bit modulus timer has rate of 6 OMHz 2048 29296 875 Hz 11 bit modulus timer has overflow period of 34uSec 21 bit upcounter rate is 34uSec 11111111 1111 1111 1111 1 0 0 1 34uSec 00 0800 112 68uSec 00 1000 W I 140uSec 00 2000 18 280uSec 00 4000 110 560uSec 00 8000 20 1 1mSec 01 0000 40 2 2mSec 02 0000 80 4 4mSec 04 0000 100 8 8mSec 08 0000 200 17 6mSec 10 0000 full word mask 0004 0000 Sms 0008 0000 17ms 0010 0000 34ms 0020 0000 68ms 0040 0000 140ms 0080 0000 280ms void timerAlign void int iTime iDelay iTime RTICNTR wait for 0 to 1 transition while iTime amp TIMER MAXVAL 0x00000000 f H for iDelay 0 iDelay lt 8 iDelay iTime RTICNTR 32 Firmware Code SLVU468 June 2011 f Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS www ti com SLVU468 June 2011 Submit Documentation Feedback wait for 1 to 0 transition while Time amp TIMER MAXVAL 0x00000000 for iDelay 0 iDelay lt 8 iDelay iT ime RTICNTR J check for timer 17ms overrun char timerCheck void int iTime char cRetVal 0x00 iTime RTICNTR if iTime amp TIMER MAXVAL 0x00000000 cRet Val OxFF J ifdef NO_TIMEOUT cRetVal 0x00
34. r all legal regulatory and safety related requirements concerning their products and any use of TI products in such safety critical applications notwithstanding any applications related information or support that may be provided by TI Further Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety critical applications TI products are neither designed nor intended for use in military aerospace applications or environments unless the TI products are specifically designated by TI as military grade or enhanced plastic Only products designated by TI as military grade meet military specifications Buyers acknowledge and agree that any such use of TI products which TI has not designated as military grade is solely at the Buyer s risk and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO TS 16949 requirements Buyers acknowledge and agree that if they use any non designated products in automotive applications TI will not be responsible for any failure to meet such requirements Following are URLs where you can obtain information on other Texas Instruments products and application solutions Products Audio Amplifiers Data Converters DL
35. sistors are choosen for their temperature drift and hydrogen sensitivity The HEATEVM uses low temperature drift ceramic resistors with a temperature drift of 25ppm C System Design Guidelines SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated j Chapter 3 IA TEXAS SLVU468 June 2011 INSTRUMENTS Hardware Setup The HEATEVM system is controlled by the SN470R1B1M HT ARM7 microcontroller in conjunction with ADS1278 HT Octal 24 Bit 128KSPS Analog to Digital Converter ADC 3 3V1 1 8V1 RST 3 3 V2 1 8 V2 DRDY SM470R1B1M HT SPICLK ADS1278 HT Octal ARM7 Micro controller 24 Bit 128 KSPS Analog to Digital Converter Figure 3 1 HEATEVM ARM7 ADC Communications The communications between the SM470R1B1M HT ARM7 Microcontroller and the ADS1278 HT Octal 24 Bit 128KSPS Analog to Digital Converter is established by using the oscillate signal The ARM7 microcontroller reads the ADS1278 HTdata stream using the SPI1 interface on the ARM 7 The data ready line ADSync Pin 39 of the ADS1278 HT signals the ARM7 that data is ready for reading on its pin 1 which is defined as a general I O pin in software The three SPI1CLK SPI1DO SPI1DI signals from the ARM7 SPI1 are used The software setup for the SPI1 interface is polarity 1 and phase 0 and the ADS1278 HT data changes on the negative SPI1CLK The ADS1278 HT requires an external clock for operation In the default case the ARM7 generates
36. than 90 the FullRange value can be set to True so that the data can still be visible in the line charts Changes to this file are only interpreted at the application start So if a change has been made here the software must be closed and re opened to recognize it SLVU468 June 2011 Calibration 23 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated 24 Calibration SLVU468 June 2011 Submit Documentation Feedback Copyright 2011 Texas Instruments Incorporated Chapter 8 IA TEXAS SLVU468 June 2011 INSTRUMENTS Firmware Code Listed below is a printout of the Firmware code supplied with the HEATEVM This code is written in C programming language using the IAR Workbench for the SM470R1B1M HT ARM7 Master file for ARM7 Tool firmware Platform IAR Workbench MS Windows Target TMS470R1B 1M Master Oscillator speed 7 500MHz Send a 1 25 MHz clock to drive the A DC conversions Send SPI CLK to A DC SPI system SPIch1 Read SPI MISO from A DC Send SCI RS 232 data out to retrieval device COM 1 New tool version no Icd no Port D Febrary 2011 Alastair Black Charles D Normann ei Ka Notes for tool characteristics REF OSC from Experimenter Board SMHz SYSCLK REF OSC x 8 40MHz ICLK SYSCLK 2 20MHz CLKDIV 2 CLKOUT ICLK 16 1 25MHz EPCON 16 RS232 57600 00 01 45 include lt intrinsic h gt include iotms470rlb1 m h include tms470r
37. warranty or endorsement thereof Use of such information may require a license from a third party under the patents or other intellectual property of the third party or a license from TI under the patents or other intellectual property of TI Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties conditions limitations and notices Reproduction of this information with alteration is an unfair and deceptive business practice TI is not responsible or liable for such altered documentation Information of third parties may be subject to additional restrictions Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice TI is not responsible or liable for any such statements TI products are not authorized for use in safety critical applications such as life support where a failure of the TI product would reasonably be expected to cause severe personal injury or death unless officers of the parties have executed an agreement specifically governing such use Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications and acknowledge and agree that they are solely responsible fo
Download Pdf Manuals
Related Search