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1. Lvl Menu item Function 2 INITIAL CONFIG Return instrument to factory default settings 2 POWER ON RECALL Power on state of instrument 3 ON Remembers state at last power down 3 OFF Does not remember state at last power down 2 INPUT RECALL Remember whether load was ON If load was ON prior to turning the power off the ON 3 ON state will be resumed after power on POWER ON RECALL must also be on for this to work 3 OFF After power on the instrument will be in the OFF state 2 KEY SOUND SET 3 ON Enable audible beep when key is pressed 3 OFF No sound when key is pressed 2 KNOB LOCK SET 3 ON Rotary knob is non functional 3 OFF Rotary knob is functional 2 SHORT CUT RECALL ges recall a setup register by pressing a number 3 ON Allows quick recall of a setup by pressing the number key 3 OFF Pressing a number key does not recall a setup 2 RANGE SELECT Change the precision of displayed values Allows the user to select the instrument s range giving 3 ON better voltage and or current resolution Press Shift 4 or Shift v to toggle resolutions 3 OFF Current and voltage measurement resolution are fixed 2 REMOTE SENSE See the Remote sense section 3 ON Remote sensing is on 3 OFF Remote sensing is off 2 ADC UPDATE RATE Set the rate at which the display is updated 3 HIGH 3 LOW 2 TRIGGER SOURCE How the instrument is triggered 3
2. common characteristics for all DC load models FP 0 1 10 Q 1 0 3 FS 0 001 Q ode Regulation 2 9 9 Input current 2FS 10 10 99 O 1 0 3 FS 0 01 0 Input VoltagezFS 10 100 999 O 1 0 3 FS 0 10 1K 4 KO 1 0 8 FS 10 CW Mode Regulation 0 100 W 1 0 1 FS 1 mW Input current 2FS 1096 Input Voltage2FS 10 100 W max Power 1 0 1 FS 100 mW Power Measurement 0 100 W 1 0 1 FS 1 mW Input current 2 FS 10 Input Voltage 2 FS 1096 100 max Power 1 0 1 FS 100 mw Battery testing function RN jm 120 ae Ae B 999 A H esolution 10 m imer range 1 sec Transition Mode Range of Frequency 0 1 Hz 1 kHz Frequency error rate 0 596 NOTE Specifications and information are subject to change without notice Please visit www bkprecision com for the most current product information Environmental Conditions This instrument is intended for indoor use in a pollution degree 2 environment Operating environmental limits are as follows 8500 DC Load Series Version February 4 2009 Page 16 of 76 Parameter Specification Humidity lt 95 relative humidity non condensing Altitude lt 2000 m 220 AV 10 47 63 Hz 110 AV 10 47 63 Hz Operating temperature 0 40 C AC Line voltage Storage temperature 10 60 C Internal Resistances The internal resistances of the DC load models are less than or equal to the following values
3. 8500 DC Load Series Version February 4 2009 Page 49 of 76 Command Group Byte Action Ox3C Set how lists repeat ONCE or REPEAT Ox3D Read how lists repeat Ox3E Set the number of list steps Ox3F Read the number of list steps 0x40 Set one of the step s current and time values 0x41 Read one of the step s current and time values 0x42 Set one of the step s voltage and time values 0x43 Read one of the step s voltage and time values 0x44 Set one of the step s power and time values 0x45 Read one of the step s power and time values 0x46 Set one of the step s resistance and time values 0x47 Read one of the step s resistance and time values 0x48 Set the list file name 0x49 Read the list file name Ox4A Set the memory partitioning for storing lists Ox4B Read the memory partitioning for storing list steps 0x4C Store the list file 0x4D Recall the list file Battery testing 0x4E Set minimum voltage in battery testing 0x4F Read minimum voltage in battery testing LOAD ON 0x50 Set timer value of for LOAD ON 0x51 Read timer value for LOAD ON 0x52 Disable enable timer for LOAD ON 0x53 Read timer state for LOAD ON Address 0x54 Set communication address LOCAL 0x55 Enable disable LOCAL control Remote sensing 0x56 E
4. Keys Display Shift Menu ii Enter MODE SET Enter Select mode This will cause the annunciator to turn on Enter MODE SET VES Enter Enter Select AZN Enter How many steps this list has Enter the number 5 5 Enter Set the current for the first step Enter 3 3 Enter Set the duration for the first step Enter 1000 1000 Enter Repeat the current and duration entry for the following 4 steps Enter The 1 is underlined indicating you can enter a number to specify the file i e block of EEPROM to store this list to Choose a number via the keypad or the knob You can choose any number between 1 8 Enter Esc Esc Standard display First press the On Off key The load will sink the current that is stored as the CC mode parameter set it to O A if you don t want an initial current Then press Shift Trigger to have the list start executing Should you wish to have the list only execute once after the trigger you can edit the list to use He eS instead of Ha sil To exit List mode press the Shift and Trigger key Test files Test files are a generalization of lists they let you generate a sequence of tests using different 8500 DC Load Series Version February 4 2009 Page 37 of 76 modes mode parameters and durations They are useful for executing a set of tests on a device then displaying whether the tests passed or failed We will illustrate how to use test files by a short exam
5. Model Internal Resistance mQ 8500 lt 35 8502 lt 200 8510 lt 15 8512 lt 100 8514 lt 8 8518 lt 5 8520 lt 45 8522 lt 30 8524 lt 6 5 8526 lt 15 Operational power curve The DC load s output follows a power curve illustrated below Rated power A ADVLIOA LNdNI Input current Rated current 8500 DC Load Series Version February 4 2009 Page 17 of 76 The curved portion is where the dissipated power is at the rated power of the instrument and is actually a hyperbolic shape When you use the menu to set lower than maximum power or current the operating region may look like the following Rated voltag z Software Power Limit c Software Current Limit gt o m lt A Input current Rated current Note the gap between the operating region and the current axis for lower voltages More detail is described in the following section Low Voltage Characteristics The following graphs show the voltage current relationships for low voltages 260A 8518 8524 8514 200A 200A 180A Current Current 140A 120A 80A 60A 40A 20A 0 3V 0 6V 0 9V 1 2V 1 5V 1 8V 21V 24V 27V 3 0V 33w 02V 04V 06V 0 8V 10V 12V 14V 16V 1 8V 20V 22V 24V 26V Voltage Voltage 8500 DC Load Series Version February 4 2009 Page 18 of 76 260A 240A 8520 200A 200A 180A 160A Current 140A 120A 100A 80A 60A 40A 20A 12V
6. l set Standard display of voltage and current or you ll be asked to enter a current value 8500 DC Load Series Version February 4 2009 Page 33 of 76 Keys Display Shift S Tran 33T VP 9 You are being prompted for the first current value Press the 5 key for 5 A Enter Enters the 5 A value then displays WAPA NP You re being prompted for the duration of the 5 A load press the 3 key for 3 ms Enter Enters the 3 ms value then displays VS MESS S You are being prompted for the second current value Press the 1 and 0 keys to enter 10 A Enter Enters the 10 A value then displays WAPA ASA You re being prompted for the duration of the 10 A load press the 2 key for 2 ms Enter Enters the 2 ms duration then displays Rede BI Iel E HINT Ni Mec c B Use the 4 or v arrow keys to display Or Enter Returns to the standard display of voltage and current To activate this continuous transient condition press Shift Tran then press On Off The load will begin switching between the two Tran values with the timing you entered Pulse transient operation In pulse transient operation the load operates at the A value that has been entered until a trigger is received At the trigger the load switches to the B value and stays at that level for the B timing value Then the load switches back to the A value and stays there until another trigger is received Here s an exampl
7. The first three lines of the main function set up a serial port to talk to The next five lines construct the string that we will send to the DC load The chr function creates a single character that has the ASCII value of the argument The symbols allow strings to be concatenated The expression chr 0 a number creates a string of ASCII 0x00 characters whose length is a number The last character is the checksum of the previous 25 characters calculated for us by the CalculateChecksum function When a command is sent to the instrument you must always request for return data which will always be another 26 bytes This is also dumped to the screen You can download a complete python program along with detailed documentation from our website at www bkprecision com 8500 DC Load Series Version February 4 2009 Page 47 of 76 Here are the printed results when the above script is ran Set to remote command aa 20 01 cb Response aa 12 80 30 The characters represent the bytes with a value of 0x00 This makes it easier to see the nonzero bytes in the string The first byte of a command is always 0xaa and the second byte is the address of the DC load The address should be set to 0 The third byte identifies the command set to remote and the fourth byte is a 1 which means enable remote mode If the fourth byte was 0 this command would set the DC load to local mode The third byte of the response string is 0x12 whi
8. ere rp neos eter exec heen aa ue A xe aln E dd eR diay ERR aer kv xa E dy E Nerv Eo Y Riu 33 Continuous transient operatioh treni Aa EEEE E RERE EEKEREN 33 Pulse transient OPEratiOn cccccccccseseccceceeeseeceeceeeecceeceseeeeeeeeeseeceeseesseceeseaeaeeeeessaaeeeeeeseneeegaaes 34 Toggled transient NTA NETTO TET 35 Toggle between two IS MCI T NETTE OTT 36 Lists dynamic CO MG TOMI RTT CODI IDOL QE TEE 36 h L Fp ae iL ui lee ED II lE ID DI EI NL EL EIN E RUET 37 8500 DC Load Series Version February 4 2009 Page 3 of 76 MINUS SUING I EE 39 Voltage threshold ale TID 0 2 0 00010 EU 40 lads iE lNB EET QS 40 Protection features eese seteenti nk hne pin tRm areas iima Ell Gali R3 XR R24 lia iP Ria RReRa laf Rie ierif e radraai 40 Over Voltage DIODSCUDEL eoi Lagu sedges ice Sirac andans utu aaa a Nae EPA AARAA aAa eaaa K Eaa nEn nnda tapas 41 Over Current protection ssssssssssssssssseeseeeeeeeee nennen rn nnn nnns ness nne nene na nnn nente nennen 41 Over Poweasl protecHof 5 1 0 nenia Co divo E Pe E rc EEEE Ee ee aeta di iege EN EEEE duedi secre 41 Reverse voltage BIOIBOIOPL uoi een tror bea pax sese dap rca ER CHA HM M Va qna rMM E Ra E RM DEDERE 41 Over Temperature protectio nresnani En Ease e NER XXn a Ee E ERE o RESO REN EEA MIRA M URP To 42 FROMIOLO SOR SIFIG 25528 serere iret rrt naveddsundcasacesnncaithss aunt E d raten aliu e deMantesu
9. 0 1 mA 4 Lower high byte of current 5 Upper low byte of current 6 Upper high byte of current 7 24 Reserved 0x2C Set CV mode voltage Byte offset Meaning 3 Lower low byte of voltage 1 represents 1 mV 4 Lower high byte of voltage 5 Upper low byte of voltage 6 Upper high byte of voltage 7 24 Reserved 0x2D Read CV mode voltage Byte offset Meaning 3 Lower low byte of voltage 1 represents 1 mV 8500 DC Load Series Version February 4 2009 Page 55 of 76 Byte offset Meaning 4 Lower high byte of voltage 5 Upper low byte of voltage 6 Upper high byte of voltage 7 24 Reserved Ox2bE Set CW mode power Byte offset Meaning 3 Lower low byte of power 1 represents 1 mW 4 Lower high byte of power 5 Upper low byte of power 6 Upper high byte of power 7 24 Reserved Ox2F Read CW mode power Byte offset Meaning 3 Lower low byte of power 1 represents 1 mW 4 Lower high byte of power 5 Upper low byte of power 6 Upper high byte of power 7 24 Reserved 0x30 Set CR mode resistance Byte offset Meaning 3 Lower low byte of resistance 1 represents 1 O 4 Lower high byte of resistance 5 Upper low byte of resistance 6 Upper high byte of resistance 7 24 Reserved 0x31 Read CR mode resistance Byte offset Meaning 3 Lower low byte of resistance 1 represents 1 O 4 Lower high byte of resistance 8500 DC
10. 4 2009 Page 10 of 76 not covered by warranty 4 Line voltage selection switch 110 VAC or 220 VAC Display annunciators Annunciator Meaning OFF The load is off UNG The input is unregulated Constant current mode CV Constant voltage mode Constant power mode Constant resistance mode PROT Not used Transient operation is enabled LIST List mode is initiated or running Remote sensing is on m Not used An error has occurred a The instrument is communicating with an IT E131 or IT E132 communications adapter This annunciator will stay lit for approximately 3 seconds after the last remote communication with the DC Load Instrument is in the remote state The only active key is the Local RMT key This is set with the 0x20 remote command see the Remote programming section SHIFT The Shift key has been pressed LOC The keyboard is locked by a password Menus Use Shift Menu to enter the menus Lvl indicates the menu level which is also indicated by the indentation of the menu item text Scroll through the menu items using the and v keys Return to a previous menu level by pressing the Esc key Words in the heavy font such as OFF indicate the default menu selection Lvl Menu item Function 1 CONFIG 8500 DC Load Series Version February 4 2009 Page 11 of 76
11. Displays B35 M LP 9 e 9 6 You are being prompted for the second current value Press the 1 and 0 keys to enter 10 A Enter Enters the 10 A value then displays jM PS You re being prompted for the duration of the 10 A load In the toggled mode of operation this width is ignored so enter any convenient value Enter Displays Hele iub ee s HATE or giejcic B d Use the or v arrow keys to display Enter Returns to the standard display of voltage and current To activate this toggled transient condition press Shift Tran then press On Off The load will start at the value you entered for A 5 A Then press Shift Trigger to cause the load to switch to the B level of current 10 A The next trigger will cause the load to shift back to the A level 5 A Subsequent triggers repeat this behavior NOTE This example requires the CONFIG TRIGGER menu item be set to IMMEDIATE If set to EXTERNAL you d trigger the instrument with a high TTL level signal on the trigger terminals on the rear panel If set to BUS you d trigger the instrument with a software trigger Toggle between two test values When you have entered A and B values through the Shift S Tran menu those values are available to you at the front panel Suppose you set the instrument to operate in CC mode at a current of 1 A If the transient A level was 5 A and the transient B level was 10 A you can set the instrument to the A level by pre
12. IMMEDIATE Triggered from the Shift Trigger key Sl ee NN SADS 3 BUS Triggered from a serial bus command 2 CONNECT MODE 3 MAXTIPLEXING uS T this hardware Should actually say 3 SEPARATE 8500 DC Load Series Version February 4 2009 Page 12 of 76 Lvl Menu item Function 2 BAUDRATE SET Set the serial bus connection speed 3 4800 3 9600 3 19200 3 38400 2 COMM PARITY SET Serial connection parity 3 NONE 3 EVEN 3 ODD Set the instrument s address Must be an integer S ADDRESS SET between 0x00 and OxFE inclusive Set the instrument s password to 1 4 digits Press the Enter key without any data entry to remove the 2 KEY LOCK SET password If you accidentally locked the keyboard follow instructions at the end of this manual chapter in case of trouble to unlock the keypads 2 EXIT Return to prior menu level 1 SYSTEM SET Set the maximum allowed current Exceeding this 2 MAX CURRENT SET value will cause the load to shut off This value also becomes the maximum current you can set Set the maximum allowed power Exceeding this value 2 MAX POWER SET will cause the load to shut off This value also becomes the maximum power you can set Set the maximum allowed voltage Exceeding this 2 MAX VOLTAGE SET value will cause the load to shut off This value also becomes the maximum voltage you can set Used to set an ON voltage thresho
13. Load Series Version February 4 2009 Page 56 of 76 Byte offset Meaning 5 Upper low byte of resistance 6 Upper high byte of resistance 7 24 Reserved 0x32 Set CC mode transient current and timing Byte offset Meaning 3to6 Value A of current in units of 0 1 mA Little endian 4 byte number 7to8 Time for A current in units of 0 1 ms Little endian 2 byte number 9to 12 Value B of current in units of 0 1 mA Little endian 4 byte number 13 to 14 Time for B current in units of 0 1 ms Little endian 2 byte number 15 Transient operation 0 is CONTINUOUS 1 is PULSE 2is TOGGLED 16 24 Reserved 0x33 Read CC mode transient parameters Byte offset Meaning 3to6 Value A of current in units of 0 1 mA Little endian 4 byte number 7to8 Time for A current in units of 0 1 ms Little endian 2 byte number 9to 12 Value B of current in units of 0 1 mA Little endian 4 byte number 13 to 14 Time for B current in units of 0 1 ms Little endian 2 byte number 15 Transient operation 0 is CONTINUOUS 1 is PULSE 2is TOGGLED 16 24 Reserved 0x34 Set CV mode transient voltage and timing Byte offset Meaning 3to6 Value A of voltage in units of 1 mV Little endian 4 byte number 7to8 Time for A voltage in units of 0 1 ms Little endian 2 byte number 9to 12 Value B of voltage in units of 1 mV Little endian 4 byte number 13 to 14 Time for B voltage in unit
14. Mel message on the display if the voltage is too high To change back to the lower voltage resolution press Shift again Short When a test mode is on you may press Shift Short to emulate a short This will draw maximum current from the DC supply in any of the four operation modes CC CV CW or CR In CC CV or CR mode you may press Shift Short to stop the short The DC Load will return to its previous operation However in CW mode the short current will continue to be drawn to stop the short you must press the On Off key Note When emulating a Short while in CV mode the current software limit may trigger the DC load Input to turn Off provided the current limit is reached This does not affect the programmed settings and the DC load will restore the previously programmed values once the Short condition is removed Battery test The battery test feature measures the time it takes for a battery voltage to drop to a specified value while drawing a constant current from the battery When the voltage at the DC Load s terminals reaches the specified voltage the test is ended and the integrated current i e charge supplied by 8500 DC Load Series Version February 4 2009 Page 32 of 76 the battery in ampere hours A hrs of the battery is calculated and displayed To run a battery test follow these steps Key presses Display l set enter current value with Set the DC Load to constant current mode and set the nume
15. Passwords If you enter the menu CONFIG KEY LOCK SET you can set a one to four digit password This password will be required when changing settings from the front panel The only operations allowed without entering the password are Shift A Shift B Shift Short Shift Tran Shift Trigger On Off To remove the password enter the menu CONFIG KEY LOCK SET and do not press any number keys then press Enter Protection features To protect external hardware when using the DC Load you can set the maximum allowed values for current voltage and power These settings will override any settings subsequently made from the front panel using the l set V set P set or R set keys 8500 DC Load Series Version February 4 2009 Page 40 of 76 To set these protection values use the following keystrokes Keys Display Shift Menu CONFIG v SYSTEM SET Enter Select between using the 4 and v arrow keys then press Enter Enter the desired value then press Enter to accept it Esc Esc Exit from the menu Example Suppose you are measuring current vs voltage characteristics of a 1 watt resistor You could set the maximum allowed power to 1 1 watts to test the resistor s rating yet not go over the maximum rating by more than 10 to ensure you don t destroy the resistor If you tried to use the P set key to set the power to more than 1 1 W the instrument will limit the set value to 1 1 W Ove
16. Reserved 0x53 Read timer state for LOAD ON Byte 3 0 is disable timer 1 is enable timer 4 24 Reserved 0x54 Set communication address Byte 3 2 byte little endian integer specifying the address Must be between 0 and OxFE inclusive 4 24 Reserved 0x55 Enable disable LOCAL control Byte 3 0 means to disable the Local key on the front panel 8500 DC Load Series Version February 4 2009 Page 64 of 76 Byte 0x5A offset Meaning 1 means to enable the Local key on the front panel 4 24 Reserved 0x56 Enable disable remote sensing Byte offset Meaning 3 0 means to disable remote sensing 1 means to enable remote sensing 4 24 Reserved 0x57 Read the state of remote sensing Byte offset Meaning 3 0 means remote sensing is disabled 1 means remote sensing is enabled 4 24 Reserved 0x58 Select trigger source Byte offset Meaning 3 Trigger 0 means immediate trigger i e triggered from the front panel 1 means external trigger from the rear panel connector 2 means a bus software trigger the 0x5A command 4 24 Reserved 0x59 Read trigger source Byte offset Meaning 3 Trigger 0 means immediate trigger i e triggered from the front panel 1 means external trigger from the rear panel connector 2 means a bus software trigger the 0x5A command 4 24 Reserved Trigger the ele
17. are in base 10 number system unless otherwise indicated 3 Byte numbering is zero based meaning numbering starts with 0 The structure of each 26 byte packet is Byte 0 Byte 1 Byte 2 Byte 3 to 24 Byte 25 OxAA Address Command Command s data Checksum Thus the first byte of any command packet or returned packet is always OxAA Address must be a byte that is between 0x00 and OxFE Setting of the address is optional It is not required to communicate with the instrument The address can be set from the front panel and is stored in non volatile memory This feature is useful when communicating via USB and connecting several instruments e g via a USB hub In this scenario Windows assigns a virtual COM port to each device which is unknown prior to establishing communications with the instrument could be different each time In this case the user can correlate each virtual COM port randomly assigned by Windows with a user defined address Command is a byte that identifies which DC Load command is used The area for the command s data contains parameter information for the command or the data that is requested via a previous command Some commands have no data at all It is a good programming practice to set all unused bytes to 0x00 8500 DC Load Series Version February 4 2009 Page 45 of 76 The checksum number is the arithmetic sum of each of the bytes modulo 256 Status packets When you send a comma
18. cece taco net 75 8500 DC Load Series Version February 4 2009 Page 4 of 76 Notation l set Represents a key on the front panel Note that some of these may be accessed in combination with the Shift key OFF Annunciator value or message shown on the vacuum fluorescent display CONFIG Menu item OFF Default menu item 8500 DC Load Series Version February 4 2009 Page 5 of 76 Quick reference Model numbers covered by this document The B amp K Precision DC Loads covered by this manual are 8500 8502 8510 8512 8514 8518 8520 8522 8524 8526 Unless otherwise noted this document will refer to all of these instruments as the DC Load Instrument differences where appropriate will be noted Options and accessories The items included with the instrument are Power cord User manual Installation CD with application software PV8500 and USB driver for optional TTL to USB adapter 4 TTL to RS232 serial converter IT 131 5 Test report Optional accessories are 6 T rack mount kit IT E151 TTL to USB serial adapter IT 132 Overview of instrument The DC Load is a two terminal device that can be connected to DC sources Here a DC source is a voltage that is always positive on the DC Load s terminal referenced to the terminal DC Electronic Loads are used for design manufacturing and evaluation of DC power supplies batteries and power components Other a
19. from the menu The following diagram shows the remote sensing terminals on the back of the instrument The following shows a wiring diagram for remote sensing 8500 DC Load Series Version February 4 2009 Page 42 of 76 Wiring diagram for remote sense Example A power supply is connected to the DC load with 72 5 cm of 20 gauge solid copper wires The constant current i set to 5 A The power supply s output meter reads 27 0 V and the DC Load s voltage display reads 26 71 V with a power dissipation of 133 70 W This is without remote sensing enabled With remote sensing turned on and the remote sensing terminals connected to the power supply output terminals the DC Load reads 26 98 V and indicates 134 95 W of power dissipation This demonstrates that 134 95 133 70 1 25 W is dissipated in the 20 gauge wires From the resistance per unit length of 20 gauge wires the expected dissipated power at 5 A can be calculated as 1 21 W Saving and Recalling settings The DC Load provides 25 non volatile registers to save instrument settings for recall later To save the instrument s settings to a register press Shift Store You ll be prompted for a register number Enter a number between 1 and 25 then press the Enter key The settings are saved Note that this will overwrite any values previously saved in that register To recall the instrument s settings from a register press Shift Recall You ll be prompted for a r
20. to be sent in the command packet byte 2 Command Group Byte Action Return data 0x12 Indicates a packet that returns the status of the last command you sent to the DC Load Remote 0x20 Set the DC Load to remote operation ON OFF 0x21 Turn the load ON or OFF 0x22 Set the maximum voltage allowed 0x23 Read the maximum voltage allowed Maximum parameter 0x24 Set the maximum current allowed values 0x25 Read the maximum current allowed 0x26 Set the maximum power allowed 0x27 Read the maximum power allowed 0x28 Set CC CV CW or CR mode 0x29 Read the mode being used CC CV CW or CR Ox2A Set CC mode current Ox2B Read CC mode current Ox2C Set CV mode voltage Ox2D Read CV mode voltage Ox2E Set CW mode power Ox2F Read CW mode power 0x30 Set CR mode resistance Operation mode Mode parameters Ox31 Read CR mode resistance 0x32 Set CC mode transient current and timing 0x33 Read CC mode transient parameters 0x34 Set CV mode transient voltage and timing Transient 0x35 Read CV mode transient parameters parameters 0x36 Set CW mode transient power and timing 0x37 Read CW mode transient parameters 0x38 Set CR mode transient resistance and timing 0x39 Read CR mode transient parameters Ox3A Select the list operation CC CV CW CR Ox3B Read the list operation CC CV CW CR List operations
21. 20 V 0 60 V Input rating Current 0 120A 0 30A 0 240A 0 240A Power 600 W 1200 W 8510 8512 8514 8518 common characteristics CV Mode 0 1 18 V 0 05 0 02 FS Regulation 0 1 V to Vmax 0 05 0 025 FS 10 mV CC Mode 0 12 A 0 3 A 0 24 A 0 1 0 1 FS 1mA Regulation 0 max Current 0 2 0 15 FS 10 mA 0 12A 0 3A 0 24 A 0 1 0 196 FS 1 mA USQUE 0 max Current 0 2 0 15 FS 10 mA 8510 8514 US 0 02 0 025 FS Voltage Measurement Dol 8512 8518 Dd 0 02 0 0296 FS 0 Vmax 0 02 0 025 FS 10 mV 8500 DC Load Series Version February 4 2009 Page 15 of 76 Models 8520 8522 8524 8526 2400W amp 5000W Voltage 0 120V 0 500 V 0 60 V 0 500 V Input rating Current 0 240A 0 120A 0 240 A 0 120 A Power 2400 W 5000 W 8520 8522 8524 8526 common characteristics eter CV Mode l 0 1 18 V 0 05 0 02 FS 1 mV Regulation 0 1 V to Vmax 0 05 0 025 FS 10 mV CC Mode 0 24 A 0 12 A 0 24 A 0 12 A 0 1 0 1 FS 1mA Regulation 0 max Current 0 2 0 15 FS 10 mA 0 12A 0 3A 0 24 A 0 12A 0 196 0 196 FS 1 mA Curent Measurement 0 max Current 0 2 0 15 FS 10 mA 8522 8526 M 0 02 0 0296 FS Voltage Measurement Ye S 0 8520 8524 Uno 0 02 0 02596 FS 0 Vmax 0 02 0 025 FS 10 mV All DC load models
22. 24V 36V 48V 60V 72V 84V 9 6V 10 8V 120V 13 2V 14 4V 15 6V Voltage Slew rate The slew rate for each DC load varies from model to model The variations are also dependent on the different regions measured for each individual load In general the slew rate for low current transitions say 0 to 0 5 A is significantly lower than slew rate for current transitions from 30 to 70 A The provided table below indicates measured slew rates based on the maximum range of current transition of the models are capable of For example model 8500 s slew rate would be measured with current transition from O A to 30 A Note The graph below illustrates slew rate measurements In general the indicated slew rates in the table below are measured based on the maximum current range each model is able to handle Between the 10 and 90 region the slew rate can be measured by observing the steepest slope portion The indicated measured time would be used to calculate the slew rate Hence the slew rate calculation is simply rated max current 0 A T where T is the measured time from 10 to 90 region and rated max current is the specified maximum current of each load 8500 DC Load Series Version February 4 2009 Page 19 of 76 Voltage Current or Resistance Change Slew Rate f Measured Time Actual Time As a reference below is a table of slew rates for their respective models Model Sl
23. 6 Models 8510 8512 8514 amp 8518 Dimension 429mmW x88 2mm H x 354 6mm D Outline Diagram Unit mm Models 8520 8522 448 185 538 20 52 70 8500 DC Load Series Version February 4 2009 Page 24 of 76 Models 8524 amp 8526 Unit mm Unt IH UT UT l N IIH T MIN T IHI 8500 DC Load Series Version February 4 2009 Page 25 of 76 Model number Dimensions in mm Mass in kg 8500 215Wx88Hx355D 5 2 8502 215Wx88Hx355D 5 2 8510 429Wx88Hx355D 14 8512 429Wx88Hx355D 14 8514 429Wx88Hx355D 14 8518 429Wx88Hx355D 14 8520 444Wx180Hx539D 30 8522 444Wx180Hx539D 30 8524 444Wx357Hx539D 67 8526 490Wx357Hx539D 67 Bench operation The 8500 DC Load is provided with a carrying handle The following pictures demonstrate various ways to use the handle Ss c i c c a The handle may be removed if desired A rack mounting kit IT E151 is also available 8500 DC Load Series Version February 4 2009 Page 26 of 76 First turn on checkout Ensure that the line voltage selector switch on the CAUTION back panel is set to match your line voltage Failure to do so could result in damage to the instrument Connect an appropriate IEC power cord to the DC Load and plug the power cord into an AC power outlet Ensure that nothing is connected to the INPUT terminals Turn the instrument on by pushing the Power butto
24. BK PPaIC MmaAr Pie iwi USER MANUAL 8500 SERIES DC ELECTRONIC LOADS Models 8500 8502 8510 8512 8514 8518 8520 8522 8524 amp 8526 Safety The following general safety precautions must be observed during all phases of operation of this instrument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument B amp K Precision assumes no liability for the customer s failure to comply with these requirements Verify that all safety precautions are taken Note the instrument s external markings described under Safety Symbols This product is a Safety Class 1 instrument which means it is provided with a protective earth terminal To minimize shock hazard the instrument chassis and cover must be connected to an electrical ground The instrument must be connected to the AC line power through a grounded power cable with the ground wire firmly connected to an electrical ground safety ground at the power outlet Note Any interruption of the protective grounding conductor or disconnection of the protective earth terminal will cause a potential shock hazard that could result in personal injury DO NOT OPERATE THE INSTRUMENT IN AN EXPLOSIVE ATMOSPHERE OR IN THE PRESENCE OF FUMES OR FLAMMABLE GASES KEEP AWAY FROM LIVE CIRCUITS Operating personnel must not remove instrument covers Component replacement and inte
25. Condition Trigger The key that causes an immediate trigger V set Configure the instrument for constant voltage mode VFD Vacuum fluorescent display the technology used for the instrument s display 8500 DC Load Series Version February 4 2009 Page 22 of 76 Installation Inspection Items you should have received When you open the box containing the instrument you should find the following items 1 The DC Load instrument Power cord User manual Installation CD with application software PV8500 TTL to RS 232 serial converter IT 131 Calibration report QUE ONT Instrument location This instrument is intended for indoor use in a pollution degree 2 environment Please refer to the specifications table for the allowable environment operating limits Significant power may be dissipated in the DC Load which includes one or more thermostatically operated fans The fans draw air through the bottom and sides and exhaust it out the back It is important to allow at least 25 mm 1 inch of clearance on all sides of the instrument so adequate cooling airflow can be maintained CAUTION Do not block the fan exhaust at the rear of the load Outline Drawings All dimensions are in millimeters mm Models 8500 amp 8502 Dimension 214 5mmW x 88 2mm H x 254 6mm D Terminal length 29 4mm Feet height 17 5mm Outline Diagram Unit mm 8500 DC Load Series Version February 4 2009 Page 23 of 7
26. Contents OEM Uy M TE Peageaanaaesneaece 2 Safety Symbols crier x nea dats i Ea e Ea XXe uer hp dep eR Ve E ER da er sn Fa d ope RR DURER da Rie FR ERE R EX RE ER k 2 eiue NA TERCERO 5 Quick reference 6 Model numbers covered by this document sss sese eee 6 Options and ACCESSOMICS ccccececeeeeeecceceeeaeeeeeeseeeeeeeeeceeeeaaaaeasaaaeeeeeeeeeeeeeeaaaaaadeeeeeeeeeesesesaaaanaeess 6 Overview of TT L dioec oete erecto ec cure added ese oce ti ro Eee ete i ead ch lame adtidianes Leste sec Shue Pe FEE EE EP EUR 6 Typical tasks secet Er E NY FEAR ER S Vea UR EFE ACE AN VE AR RENE RV ME puG HU I A PAR XR ERE EREER OUR 7 Frontpanelen eie DITIONES 7 Suis Erico Sl Beran decade TR TETTE EE mmm 9 Front panel TENERO 9 Ixear panel eee E E ET 10 Display a n nciatorS esise ner a a a Qu desea CEA SERES EE Aa Ea CR RE wk EKT 11 EAEE I e AN ARRE E A PEA EAA M PEE AE AA A E LL dU E AAA 11 SPSCMICAUONS iiir TTC ELDER RTIDRUREE 15 Environmental Conditong iced toe eto an toto douce eso doeet eet eese ese ed cu tee te nean tete een ne eRI RI RI ERI RARES 16 intemal FReSIStalC8B dernier da rocteeec e eere ie Gace erectos ree bte Beets die leue AMA he 17 Operational power C tve iesus cim ece cse ue pera In pns e ska Dinan R wr em OR Pa asap cA MR RR EP D Ma PR RA D RR a DR Rar I RRR 17 Low Voltage Characteristics 5 eere tr neo deep dr re x ne nde DIR doe ER n E
27. It will stay lit for approximately 3 seconds after the last command was received A list is a stored sequence of test parameter and test duration values These are used for dynamic load profiles Returns control to the front panel Show the top level item of the instrument s menus Mode of operation of the instrument The four modes are CC CV CW and CR Parameter values for CC CV CW and CR modes On Off Manually toggle the instrument between its set mode and an infinite impedance state P set Configure the instrument for constant power mode Power Power switch to turn the instrument on and off 8500 DC Load Series Version February 4 2009 Page 21 of 76 R set Configure the instrument for constant resistance mode Recall Recall instrument state from non volatile memory Remote sensing Allows the instrument to measure the load power properly in case of large currents by sensing the voltage at the source rather than at the instrument s terminals This removes the effect of the resistance of long leads S Tran Set parameters A B and transition times for transient mode Shift Shift key which allows access to the functions written beneath the number keys Short Toggles between normal operation and a low resistance short Store Allows the user to save the instrument state in non volatile memory Test file A sequence of different test modes used for automated testing Tran Set to transient condition Transient condition See
28. R EYE CREE CER dias 18 LS TEE EE 19 COET EEA E ETERNA IPC 21 EEEE S 1 E EEE A E EE E AE E E anand EEE TE AT E T A TE 23 T 9 Te fore sroin C M 23 items vou should have TORCEIVBEL Ae ee ee eres 23 instrument ea 23 Outline IDFAWINGS cccaceccaceecessnsecdececsedeannctdceasenseadevadcnchdcondagadnaweuceddeasidecndeadsataudugadesdaess vesandaaecnabeneaertecie 23 Bench OPERA LST 26 Freio E CME CK OU Es as eco deae orae ee oed Food edo retos reet ee ioni pec RI e Bi RER P03 b3 0136 27 Operationalmttoduetlohi cui athens petet ito mute tender cen tine d eret been o dud reete dea et ee Ae ao 28 POWGISOPCSIalG ceci eet etre iet sveltom EE DI sareeitendeses 29 Constant current mote asen aay gaan ertet anaa Vah aA ee g tem ER clad at ga een OLLI ELEM R aL an Shoals ead 29 Constant voltage mode sss 30 Gonstarit power mocle reser eiaa r serere eta phe a deiae Ai EREIRPKrai b ERAEN SPORE 30 Constant resistance mote tte re teret tees exten tei tme NES ERE cies ti c enden i ve KESAS a nac 31 WEG eoo ESI DTE k DTI ELLE 31 Changing display resolution ovd eror Por khe e avg e Fed Ya FEY XY ke Ven IE ley E gn ARE YR PR ER CR E NF AR ET 32 Increasing current resolution sees ex exe eee eee 32 Increasing voltage SUNN 55 55sec cans sees ccacigtsncssoucadbseidace ceccespascantcedd siiacsddsnecdusueeeescvendonaledic 32 NE EET m H 32 SZT L d L RM ETE 32 Transient operation 2
29. R test Constant current mode Constant voltage mode Constant power mode Constant resistance mode Timed on off CC CV CW or CR test Constant current mode Constant voltage mode Constant power mode Constant resistance mode Timed operation Triggered CC CV CW or CR test Constant current mode Constant voltage mode Constant power mode Constant resistance mode Triggering Constant load with one transient Transient operation Load with multiple transients Lists dynamic condition Determine A hr characteristic of battery Battery test Run a sequence of tests Test files Front panel The following picture is the front panel for the 8510 DC Load All models have the same front panel only the terminal section will vary based on the model 8500 DC Load Series Version February 4 2009 Page 7 of 76 Button Function s E 16 character display shows voltage and current measurements Rotary knob Turn to adjust a setting value Press in to toggle between setting the currently selected mode s value and reading the voltage and current as shown in the above picture IS lel Power switch to turn the instrument on or off Numeric keypad Numeric entry keys Secondary key functions Di Keypad Enable disable input Set up the current voltage power and resistance modes Scroll through menus and options lel Input terminals Depending on the model
30. a eoi Rede tore eee desides desee ida 32 Draw a constant power eeeeeeeeeeeeee 6 e eI IT 10 12 22 32 Draw a constant voltage ssssussssss 6 Standard display sssssssssess 34pp Dynamic condition sss sss sese eee QA e TTT 10 22 EET toco pole teinte Seances 10 159 PESE cece eeeoccic c toc ee coc ice ie eo eee fte t eot Pos eot tede ee tote 22 lf ct 10 12 Transient condition eene 22 S6 nec Ati ee RU ie en en te 21 Transient mode eene 21 LSU men 11 13p 21 36 Tigger seene 11pp 22 39 Eorc i Em SANE MEC 22 MERU msc Saree A ta oe X ox 8221 2x8 D cni CDS Eae ce n a EI foe 32 Menu SVSIGIL cip Ro ob un eno tee oo cent atc es TO Nic Sets dieses tee eats bale eran Salad A E E 21 ModE eee ee a EET 21 8500 DC Load Series Version February 4 2009 Page 75 of 76 BX PSY 22820 Savi Ranch Parkway Yorba Linda CA 92831 Printed in China 8500 DC Load Series Version February 4 2009 Page 76 of 76
31. ain The 2195 annunciator will be displayed On Off Turns the constant power load on The annunciator will be on orv Momentarily display the power level and the set power value On Off Turns the load off To operate the DC Load in CW mode in a transient condition see the Transient operation section To operate the DC Load in CW mode in a dynamic condition see the Lists section Constant resistance mode In constant resistance mode the DC load will behave as a fixed resistance value To set up the DC Load to operate in constant resistance mode and in the steady state condition use the following keystrokes Key Display R set If you press this key after powering up and there is no currently stored constant resistance value you ll be prompted for the desired resistance If there was a resistance value already stored it will be momentarily displayed and the instrument will be in CR mode If ou wish to change the resistance setting press R set again The annunciator will be displayed On Off Turns the constant resistance load on The 99 annunciator will be on or v Momentarily display the power level and the set resistance value On Off Turns the load off To operate the DC Load in CR mode in a transient condition see the Transient operation section To operate the DC Load in CR mode in a dynamic condition see the Lists section Timed operation The DC Load can be set to allow timed operatio
32. ation points for voltage These would typically span the full range of the instrument s voltage range 0x63 Send the actual voltage to the calibration program Byte 3to6 4byte little endian integer representing the voltage in units of mV 7 24 Reserved 0x64 Set current calibration point index Byte 3 Current calibration point Valid values are 0x01 to 0x04 4 24 Reserved The DC Load has four calibration points for current These would typically span the full range of the instrument s current range 0x65 Send the actual current to the calibration program Byte offset Meaning 3to6 4 byte little endian integer representing the current in units of 0 1 mA 7 24 Reserved 0x66 Store the calibration data to EEPROM Byte offset Meaning 3 24 Reserved 8500 DC Load Series Version February 4 2009 Page 68 of 76 The stored calibration data will be used the next time the DC Load is power cycled 0x67 Set calibration information Byte 3 to 22 ASCII information representing the calibration Example you might wish to store the date and time of the calibration and the initials of the person who performed the calibration 23 24 Reserved 0x68 Read calibration information Byte 3 to 22 ASCII information representing the calibration 23 24 Reserved 0x69 Restore the factory default calibration data Byte 3 24 Res
33. ay time is how long to wait before making the readback measurement If you set it to 25 5 seconds the test will halt at this point requiring you to press Shift Trigger to continue the test We ll use 1 second 1 Enter ole meets We re being prompted for the mode to use for the next step We ll again use constant current so we ll press Enter this step will also be a short so the mode doesn t really matter Enter SS UY We ll set the current to 2 5 A which is the maximum current we ve allowed for this test 8500 DC Load Series Version February 4 2009 Page 38 of 76 Keys Display 2 5 Enter We select short on and then press Enter v Enter We want to readback the current so we press Enter Enter Our minimum value is 2 0 A 2 Enter We choose 2 5 A as the maximum value 2 5 Enter We ll wait 2 seconds for the maximum current 2 Enter The 1 is underlined meaning you can choose which test file number to store this test to You can choose any number between 1 8 Here we will use 1 so just press Enter Enter Esc Esc Exit the menu The normal display is shown V and A The test file has been created and saved in file position 1 Now we will run the test on the device Keys Display Shift Menu CONFIG vy LIST SE Enter MODE SET vyv CALL TEST FILE Enter ade MEI We re being prompted for which file number to recall Since we saved to file nu
34. back to the A level 5 A NOTE This example requires the CONFIG TRIGGER menu item be set to IMMEDIATE If set to EXTERNAL you d trigger the instrument with a high TTL level signal on the trigger terminals on the rear panel If set to BUS you d trigger the instrument with a software trigger Toggled transient operation In toggled transient operation the load starts at the stored parameter for the mode When a trigger is received the load switches to the B value When another trigger is received the load switches to the A value It stays at the A value until another trigger is received at which point it switches to the B value Further triggers cause the load to switch between the A and B values Here s an example TRG Toggled Transient Operation Here are the keystrokes needed to setup this example Keys Display l set Standard display of voltage and current Enter a value of 5 A you may need to press the I set key again Press Enter Enter Enters the CC mode s value The standard display is shown Shift S Tran BSS EP 9 9 You are being prompted for the first current value Press the 5 key for 5 A Enter Enters the 5 A value then displays WAPA SS You re being prompted for the duration of the 5 A load In the toggled mode of operation this width is ignored so enter any convenient value 8500 DC Load Series Version February 4 2009 Page 35 of 76 Keys Display Enter
35. ch means this is a packet that gives the status of the last command sent The fourth byte is 0x80 which means the command completed successfully On the DC load you should see the Rmt annunciator turned on immediately after running the script You will also see the Link annunciator light up while communications are going on then blink out after a few seconds Press Shift Local to set the DC load back to local mode We ve learned two key things about the DC load 1 Commands are always sent as 26 byte packets 2 For any command you send to the DC load you must also request the return of a 26 byte packet This returned packet will either be a status packet or an information packet containing data you requested for example the power level currently set Get in the habit of looking at the LEDs on the IT E131 or IT E132 interfaces Every command you send to the DC load should result in both the RX and TX LEDs blinking once If this does not happen something is wrong with the code interface or instrument Chapter organization The remainder of this chapter contains a reference on the syntax of DC Load commands and some 8500 DC Load Series Version February 4 2009 Page 48 of 76 example programs The Summary of commands section is a list of the commands but without details The Command details section explains how to use each command Summary of commands The Byte values in the following table are used to identify the commands
36. ctronic load Byte offset Meaning 3 24 Reserved 0x5B Save DC Load s settings 8500 DC Load Series Version February 4 2009 Page 65 of 76 Byte 3 Storage register a number between 1 and 25 inclusive 4 24 Reserved 0x5C Recall DC Load s settings Byte 3 Storage register a number between 1 and 25 inclusive 4 24 Reserved Ox5D Select FIXED SHORT TRAN LIST BATTERY function Byte 3 Function 0 means FIXED 1 means SHORT 2 means TRANSIENT 3 means LIST 4 means BATTERY 4 24 Reserved Ox5E Get function type FIXED SHORT TRAN LIST BATTERY Byte 3 Function 0 means FIXED 1 means SHORT 2 means TRANSIENT 3 means LIST 4 means BATTERY 4 24 Reserved Ox5F Read input voltage current power and relative state Byte offset Meaning 3to6 4byte little endian integer for terminal voltage in units of 1 mV Tto 10 4 byte little endian integer for terminal current in units of 0 1 mA 11 to 14 4 byte little endian integer for terminal power in units of 1 mW 15 Operation state register see bit list below 16 to 17 2 byte little endian integer for demand state register see bit list below 18 24 Reserved 8500 DC Load Series Version February 4 2009 Page 66 of 76 The operation state register s bit meanings are Bit Meaning Calculate the new demarcation coefficient Waiti
37. d the newly selected mode s setting will be displayed for about 3 seconds Pressing the same mode button again will prompt for the new constant value for the selected mode There are three operational conditions for the instrument in these modes steady state transient and dynamic Condition Behavior The selected mode parameter is maintained at a constant value For example Steady state if you selected constant current mode and set the current value to 1 A the instrument would maintain this current indefinitely when the load is 0N There are two mode parameters and the load switches between these two Transient settings with user specified timing An example of a transient load in constant resistance mode would be a load of 10 O for 1 second and 20 O for 3 seconds Similar to the transient condition but capable of emulating more complex time Dynamic dependent loads The dynamic condition uses lists to specify the time dependent behavior Examples of the three conditions of operation are illustrated in the following diagram 8500 DC Load Series Version February 4 2009 Page 28 of 76 Steady state B Transient A Dynami es Repeat Time Power on state The default power on instrument state is to not remember the instrument mode settings before the last power down If you wish to have the mode settings remembered across a power down power up cycle use the following keys
38. e TWD TWD TS pms l TRIG TRIG Pulsed Transient Operation Here are the keystrokes needed to set up this example Keys Display l set Standard display of voltage and current or you ll be asked to enter a current value Shift S Tran BUI VP 9 S6 You are being prompted for the first current value Press the 5 key for 5 A Enter Enters the 5 A value then displays WAPA SS You re being prompted for the duration of the 5 A load In the pulse mode of operation this width is ignored so enter any convenient value Enter Displays BUI lt P 9 9 You are being prompted for the second 8500 DC Load Series Version February 4 2009 Page 34 of 76 Keys Display current value Press the 1 and 0 keys to enter 10 A Enter Enters the 10 A value then displays WAPA Ii NP SA You re being prompted for the duration of the 10 A load press the 1 and 0 key for 10 ms Enter Enters the 10 ms duration then displays Rede BED eteles Hale Es aiejcic B 8 Use the 4 or v arrow keys to display BaP Es 3 Or Enter Returns to the standard display of voltage and current To activate this pulse transient condition press Shift Tran then press On Off The load will start at the A level of current you entered 5 A Press Shift Trigger to cause the load to switch to the B level of current 10 A The 10 A current will last for the designated 10 ms then switch
39. egister number Enter a number between 1 and 25 then press the Enter key The stored settings are saved Note that this will overwrite all values currently set in the instrument If you try to recall a register with no data in it you will get a else B AYES error message 8500 DC Load Series Version February 4 2009 Page 43 of 76 Remote operation Communication cables The DC Load has a DB9 connector on the rear panel that allows remote communication Do not connect the DC Load s DB9 connector to a standard RS 232 instrument Doing so may damage the instrument as the instrument requires TTL logic signals not standard RS 232 voltages Two adapters are available to perform the correct level shifting RS232 to TTL serial converter cable IT 131 standard Connect the INSTRUMENT side of the adapter to the DC load DB9 connector Connect the COMPUTER end to an RS 232 port on your computer IT E131 communication The LEDs in the adapter will blink when information is sent through the adapter This is a good way to tell if your communication link is active USB to TTL serial converter cable IT 132 option The IT E132 adapter allows you to talk to the DC load via your Windows computer s USB interface To use this interface you must install the software driver that came with the IT E132 adapter To install the driver run the PL 2303 Driver Installer exe file that comes on the CD This will instal
40. endian integer specifying which step number in the list 5t08 4 byte little endian integer specifying the power in units of 1 mW 9to10 2 byte little endian integer specifying the step timing in units of 0 1 ms 11 24 Reserved 0x46 Read one of the step s resistance and time values Byte offset Meaning 3to4 2 byte little endian integer specifying which step number in the list 5108 4 byte little endian integer specifying the resistance in units of 1 Q 9to 10 2 byte little endian integer specifying the step timing in units of 0 1 ms 11 24 Reserved 7 Read one of the step s resistance and time values Byte offset Meaning 3to4 2 byte little endian integer specifying which step number in the list 5108 4 byte little endian integer specifying the resistance in units of 1 Q 9to 10 2 byte little endian integer specifying the step timing in units of 0 1 ms 11 24 Reserved 0x48 Set the list file name Byte offset Meaning 3to 12 Listfile name ASCII characters 13 24 Reserved 0x49 Read the list file name Byte offset Meaning 3to 12 Listfile name ASCII characters 13 24 Reserved 0x4A Set the memory partitioning for storing lists 8500 DC Load Series Version February 4 2009 Page 62 of 76 0x4 offset Meaning 3 Partition scheme 1 means 1 file of 1000 list steps 2 means 2 files of 500 list steps 4 means 4 files of 250 list steps 8 means 8 files of 120 list steps 4 24 Reserved Ox4B Read the memory partitioning for st
41. erved Ox6A Get product s model serial number and firmware version Byte 3to7 ASCII model information 8 Low byte of firmware version number 9 High byte of firmware version number 10 to 19 Instrument s serial number in ASCII 20 24 Reserved 0Ox6B Read the bar code information Note the bar code information is to be interpreted as ASCII data Byte offset Meaning 3to5 Identity 6to7 Sub 7to9 Version 10 to 11 Year 8500 DC Load Series Version February 4 2009 Page 69 of 76 Byte offset Meaning 12 24 Reserved 8500 DC Load Series Version February 4 2009 Page 70 of 76 Serial number and firmware version To find out the serial number and firmware version of the DC load turn the instrument on While the S a message is displayed quickly press and hold down the Shift key By pressing the and v keys you will see the following information 120V 30A 320 Instrument s capabilities SN XXX XXX XX Serial number VER X X Firmware version Press the Esc key to return to normal operation of the instrument 8500 DC Load Series Version February 4 2009 Page 71 of 76 In case of trouble Instrument won t turn on If the instrument won t turn on when the POWER switch is pressed in please ensure the power cord is plugged into the back of the instrument and the other end of the cord is plugged into a live AC power outlet If the instrument still won t turn on rem
42. ew rate 8500 0 5A u S 8502 0 5A u S 8510 1A u S 8512 0 5A u S 8514 1A u S 8518 1A u S 8520 1A u S 8522 1A u S 8524 1A u S 8526 1A u S 8500 DC Load Series Version February 4 2009 Page 20 of 76 A B Battery CC Condition CR CV CW Dynamic condition Enter Esc l set Knob click Link List Local Menu Mode Mode settings Glossary Up arrow key Used to scroll through the menu or cause the temporary display of the alternate standard display Down arrow key Used to scroll through the menu or cause the temporary display of the alternate standard display Value for first setting of transient mode Value for second setting of transient mode Select battery testing mode See Battery test section Constant current Steady state transient or dynamic Steady state condition means the load mode is operated in a steady state Transient condition means the load mode is switched between two values with user selectable timing Dynamic means multiple levels and timings are available and are gotten by using lists Constant resistance Constant voltage Constant power See Condition Choose the indicated value or setting Stop current entry and go to previous menu level Configure the instrument for constant current mode Press the knob in until it clicks This is an alternate method for changing settings This annunciator will light up when communications are coming in across the serial interface
43. ion February 4 2009 Page 59 of 76 Byte offset Meaning 3 is constant resistance CR 4 24 Reserved Ox3B Read the list operation CC CV CW CR Byte offset Meaning 3 List operation mode 0 is constant current CC 1 is constant voltage CV 2 is constant power CW 3 is constant resistance CR 4 24 Reserved Ox3C Set how lists repeat ONCE or REPEAT Byte offset Meaning 3 How lists repeat 0 is ONCE 1 is REPEAT 4 24 Reserved 0x3D Read how lists repeat ONCE or REPEAT Byte offset Meaning 3 How lists repeat 0 is ONCE 1 is REPEAT 4 24 Reserved 0x3E Set the number of list steps Byte offset Meaning 3to4 2 byte little endian integer for number of steps 5 24 Reserved 0x3F Read the number of list steps Byte offset Meaning 3to4 2 byte little endian integer for number of steps 5 24 Reseved 8500 DC Load Series Version February 4 2009 Page 60 of 76 0x40 Set one of the step s current and time values 0x4 Byte offset Meaning 3to4 2 byte little endian integer specifying which step number in the list 5to8 4 byte little endian integer specifying the current in units of 0 1 mA 9to 10 2 byte little endian integer specifying the step timing in units of 0 1 ms 11 24 Reserved 1 Read one of the step s current and time values Byte offset Meaning 3to4 2 b
44. l the driver After installation right click on My Computer and select Manage Click on Device Manager in the left hand pane then click on Ports in the right hand pane You should see an entry named Prolific USB to Serial Comm Port IT E132 communication Once the driver software is installed on your system it will appear as if you have a new COM port 8500 DC Load Series Version February 4 2009 Page 44 of 76 This COM port can then be accessed as if it were a regular RS 232 port The LEDs in the adapter will blink when information is being sent through the adapter This is a good way to tell if your communication link is active RS 232 settings In order for the computer to communicate with the DC Load both must be set to the same RS 232 settings These communication settings are 1 Baud rate must be one of 4800 9600 19200 or 38400 2 8 data bits 3 One stop bit 4 No parity Overview of DC Load programming Packet structure The DC Load is programmed using packets of bytes A packet always contains 26 bytes either going to or coming from the instrument The basic programming rule is You send a 26 byte packet to the instrument You then read a 26 byte packet back from the DC Load to either e Get the status of your submitted packet or e Get the data you requested The following are conventions we will follow in this chapter 1 Hexadecimal integers will be represented by the prefix Ox 2 Numbers
45. ld See the Voltage 2 VOLTAGE ON SET threshold section Used to set an OFF voltage threshold See the E Lai Ch SET Voltage threshold section 2 EXIT Return to prior menu level 1 LIST SET Lists are programmed sequences of load values 2 MODE SET 3 FIXED MODE Load characteristics set by front panel 3 LIST MODE Load characteristics are dynamic and controlled by a list stored in memory 2 CALL LIST FILE Recall an existing list from nonvolatile memory 3 RECALL N N is list number Note that each list file has four lists one for each 2 POES TFIEE operation mode CC CV CW CR 3 CURRENT LIST 4 ONCE List is executed once per trigger 8500 DC Load Series Version February 4 2009 Page 13 of 76 Lvl Menu item Function 4 REPEAT List is repeatedly executed after the trigger is received 3 VOLTAGE LIST 4 ONCE List is executed once per trigger 4 REPEAT List is repeatedly executed after the trigger is received 3 POWER LIST 4 ONCE List is executed once per trigger 4 REPEAT List is repeatedly executed after the trigger is received 3 RESISTANCE LIST 4 ONCE List is executed once per trigger 4 REPEAT List is repeatedly executed after the trigger is received 2 CALL TEST FILE Recalls a stored test file see Test files section 3 RECALL N N is file number 2 EDIT TEST FILE See Test files section for more details Set how the nonvolatile memory is partitio
46. ll see Connect on the display 2 Press Enter locate menu Key Lock set press Enter Enter 8512 confirm with Enter press 8500 DC Load Series Version February 4 2009 Page 72 of 76 Enter again Now the password is cleared Press Esc to exit the menu To unlock the other DC load models use the following unlock keys Model number Unlock key code 8500 8512 8502 8512 8510 8513 8512 8513 8514 8514 8518 8518 8520 8516 8522 8516 8524 8518 8526 8518 8500 DC Load Series Version February 4 2009 Page 73 of 76 Appendix Service and warranty information SERVICE INFORMATION Warranty Service Please go to the service and support section on our website www bkprecision com to obtain an RMA Return the product in the original packaging with proof of purchase to the address below Clearly state on the RMA form the performance problem and return any leads probes connectors and accessories that you are using with the device Non Warranty Service Please go to the service and support section on our website www bkprecision com to obtain an RMA Return the product in the original packaging to the address below Clearly state on the RMA form the performance problem and return any leads probes connectors and accessories that you are using with the device Customers not on open account must include payment in the form of a money order or credit card For the most current repair charge
47. mber 1 we just press Enter Enter V a Seas The test file is now loaded so we return to the normal display Esc Esc Exit the menu The normal display is show V and A Shift I set NUMEN IRI We ve entered automatic testing mode The display is showing which test file we re using Shift Trigger This starts the test You ll see the values sequentially displayed Then you ll either see BYES or WAVE You can press Shift Trigger again for another test run or press Esc to return to the normal display Esc Return to the normal display Triggering Triggering is used with the transient and dynamic conditions to allow synchronization of the DC Load s behavior with other events There are three types of triggers you may use set in the CONFIG TRIGGER SOURCE menu Trigger Type Explanation IMMEDIATE An immediate trigger is created by pressing Shift Trigger on the 8500 DC Load Series Version February 4 2009 Page 39 of 76 Trigger Type Explanation front panel keys EXTERNAL An external trigger is a TTL high signal applied to the Trigger connection on the back panel This TTL signal must last for more than 5 ms A trigger applied to this input can be used to change settings voltage current resistance toggle between settings in transient toggle mode or generate a pulse in pulse mode BUS The instrument will be triggered if a 5AH command is sent via the RS 232 interface See the Remote operation section f
48. n When you turn the load on it stays on for the specified time then turns itself off To set up timed operation use the following keystrokes Key Display Shift Menu CONFIG LOAD ON TIMER 8500 DC Load Series Version February 4 2009 Page 31 of 76 Key Display Enter TIMER STATE Enter Use arrow keys to set to KONN v TIMER SET Enter AURRAK Enter desired time interval Valid values are 1 to 60000 seconds 1000 minutes Enter TIMER SET Esc Esc Standard display Now when you turn a load on it will stay on for the designated time then turn off To turn off timed operation enter the menu Hefe a lem Rey Re Ma Sea Sea WS and set it to OF FE Changing display resolution The DC Load has two ranges of current and voltage see the specifications You can enable higher resolution for voltages and currents on the lower range Enter the menu with Shift Menu and set the menu element CONFIG RANGE SELECT to ON Increasing current resolution To increase the current resolution and change to the lower range press Shift v If the DC Load is sinking a current higher than the top end of the lower range it will be reset to the top end of the lower range To change back to the lower current resolution press Shift Y again Increasing voltage resolution To increase the voltage resolution and change to the lower range press Shift 4 You may see SUIS Ae
49. n in The instrument should MM acu ME then display OVARY A small annunciator will display in the upper left corner of the display If you do not see this display please consult the n case of trouble chapter The following test will verify the DC Load can operate properly in constant current mode Press the l set button you may have to press it twice and use the numeric keypad to set the current to 0 1 A To do this press the decimal point 1 Enter Alternatively you can adjust the current level with the knob then click the knob or press Enter Connect a power supply or battery to the DC Load observing the polarity Turn the power supply on and set a voltage of 1 volt On the DC Load press the On Off button You should see approximately 0 1 A of current flowing as shown by the instrument s ammeter and approximately 1 volt The ccf mode BK PRECISION 8500 300W Programmable DC Electronic Load annunciator should be displayed showing that the instrument is in the constant current CR The instrument s voltage display may read a bit less than the power supply s output this may be due to a voltage drop in the wires connecting the power supply to the DC Load Press the or v keys to see the power that is being consumed by the load BK PRECISION 8500 300W Programmable DC Electronic Load ik I I Press the V set button you may have to press it twice Note the load is turned off Set the power supply to 10V and the
50. nable disable remote sensing 0x57 Read the state of remote sensing 0x58 Select trigger source Triggering 0x59 Read trigger source Ox5A Trigger the electronic load Store Recall Ox5B Store DC Load s settings Ox5C Recall DC Load s settings Function Ox5D Select FIXED SHORT TRAN LIST BATTERY function 8500 DC Load Series Version February 4 2009 Page 50 of 76 Command Group Byte Action Ox5E Get function type FIXED SHORT TRAN LIST BATTERY Read display values Ox5F Read input voltage current power and relative state 0x60 Enter instrument calibration state 0x61 Get the instrument calibration state 0x62 Set voltage calibration point index 0x63 Send the actual voltage to the calibration program 0x64 Set current calibration point index Calibration 0x65 Send the actual current to the calibration program 0x66 Store the calibration data to EEPROM 0x67 Set calibration information 0x68 Read calibration information 0x69 Restore the factory default calibration data Ox6A Get product s model serial number and firmware version Product information Ox6B Read the bar code information Ox6C Set the bar code information Command details In the following please remember that the word mode only refers to one of the four operational modes of the DC Load constant current CC constant v
51. nd that does not cause the DC Load to send requested information back to you you will receive a status packet back The structure of a status packet is ByteO Byte 1 Byte 2 Byte 3 Byte 4 to 24 Byte 25 OxAA Address 0x12 Status byte Reserved Checksum The meaning of the return status byte is defined below 0x90 Checksum incorrect OxAO Parameter incorrect OxBO Unrecognized command O0xCO Invalid command 0x80 Command was successful Example program As you have seen the native programming interface to the DC loads is fairly low level It involves sending 26 byte commands and receiving 26 byte responses from the instrument To demonstrate how to write your own source code to remotely control the DC load we provide a custom program written in python which translates well into other text based languages like C C About Python Python is a dynamic object oriented programming language that can be used for various kinds of software development It offers strong support for integration with other languages and tools comes with extensive standard libraries and is easy to learn in a few days time Python is distributed under an OSI approved open source license that makes it free to use You can download a complete python program along with detailed documentation from our website at www bkprecision com Also available under the download area is a high level library which will make p
52. ned to store 2 LIST STORE MODE lists You can choose between numerous short lists or fewer longer lists 3 8 X 120 STEPS 3 4 X 250 STEPS 3 2 X 500 STEPS 3 1X 1000 STEPS 2 EXIT Return to prior menu level 1 LOAD ON TIMER Enable a timed load 2 TIMER STATE When the load timer is enabled by this menu element 3 ON the load is turned on when the On Off key is pressed After the set time period has elapsed the load is turned off 3 OFF When the load is turned on via the On Off key the load stays ON indefinitely 2 TIMER SET x the time period from 1 to 60000 s for the load to be 2 EXIT Return to prior menu level 1 EXIT Return to standard display 8500 DC Load Series Version February 4 2009 Page 14 of 76 Specifications Models 8500 amp 8502 300 W Voltage 0 to 120 V 0 to 500V Input rating Current 1 mA to 30A 1mAto 15A Power 300W 8500 8502 common characteristics 1mV CV Mode 0 1 18 V 0 05 0 02 FS Regulation 0 1 120 V 0 1 500 V 0 05 0 025 FS 10 mV CC Mode 0 3A 0 3A 0 1 0 1 FS 0 1mA Regulation 0 30A 0 15A _ 0 2 0 15 FS 1mA 0 3A 0 3A 0 1 0 195 FS 0 1 mA Current Measurement 8500 _ 0 2 0 15 FS HUP 0 15A 8502 0 2 0 3 FS TRA 0 18 V 0 02 0 02 FS 1 mV Voltage Measuremeni 0 120 V 0 500V 3 0 0296 0 025 FS 10 mV Models 8510 8512 8514 8518 1200 amp 2400 W Voltage 0 120 V 0 500 V 0 1
53. ng for a trigger signal Remote control state 1 means enabled Output state 1 means ON Local key state 0 means not enabled 1 means enabled Remote sensing mode 1 means enabled LOAD ON timer is enabled NSO a Rl wl NUN gt O Reserved The demand state register s bit meanings are Bit Meaning Reversed voltage is at instrument s terminals 1 means yes Over voltage 1 means yes Over current 1 means yes Over power 1 means yes Over temperature 1 means yes Not connect remote terminal Constant current Constant voltage co dO 0c BACON o Constant power e Constant resistance 0x60 Enter instrument calibration state Byte offset Meaning 3 Calibration state 0 means disable 1 means enable 4 0x85 low byte of calibration password 5 0x11 or 0x12 high byte of calibration password 6 24 Reserved 0x61 Get the instrument calibration state 8500 DC Load Series Version February 4 2009 Page 67 of 76 Byte offset Meaning 3 Calibration protection state Bit 0 value of 0 means the calibration state is not protected Bit 0 value of 1 means the calibration state is protected 4 24 Reserved 0x62 Set voltage calibration point index Byte 3 Voltage calibration point Valid values are 0x01 to 0x04 4 24 Reserved The DC Load has four calibr
54. of the corresponding transient operation See the Transient operation section This key does not work when the annunciator is on Shift Store Store the DC Load state in non volatile memory You may store 25 different states Shift Recall Recall the DC Load state from non volatile memory You may recall 25 different states Shift B 8500 DC Load Series Version February 4 2009 Page 9 of 76 Shift Batte Turn on or off battery testing function measures battery ry capacity in ampere hours Shift S Tran Set transient condition parameters On Off Mee DC Load ON or OFF OFF is high impedance INN ee al key indicated by the word under the key Swoldomky 3 e Dedmapon O O 5 The escape key It can be used to exit keyboard entry or move up a level in the menu Enter e Enter the selected value or setting Rear panel Your instrument s rear panel may look different from the following figure but the same functionality will be present EIL EE C s2 I mI ATO os Sas S amp S CSD EXT 1 3 pin IEC320 AC input connector 4 pin trigger and remote sensing connector 9 Pin serial port interface connector NOTE This port s terminals utilize 5 volt TTL logic signals Do NOT connect an RS 232 cable with standard RS 232 voltages on the cables connectors Doing so may damage the instrument and is EE 8500 DC Load Series Version February
55. oid if the serial number is altered defaced or removed B amp K Precision Corp shall not be liable for any consequential damages including without limitation damages resulting from loss of use Some states do not allow limitations of incidental or consequential damages So the above limitation or exclusion may not apply to you This warranty gives you specific rights and you may have other rights which vary from state to state B amp K Precision Corp 22820 Savi Ranch Parkway Yorba Linda CA 92887 www bkprecision com 714 921 9095 8500 DC Load Series Version February 4 2009 Page 74 of 76 23 Index rM isa os TRN ee la Ae ea 21 Mode SCHINGS re eed rer droites 29 Battery test 121 532 i tere LEE NU MAD S 21 poH 21 Present a constant resistance 6 ConaitiQt zv eso dm non euet N 24 RESCUE A ete AA ETET 22 Constant current 9 11 21 29 Recall ient 10 12 22 43 Constant power eeseeeessees 9 11 21 30 Remote sensing 11p 22 42 Constant resistance 9 11 21p 31 amp Resistance ostentans 31 Constant voltage 9 11 21p 30 Resistance T 31 OR usc utr ed Lac OH oed d cer 24 SSShPaba ds E O does iate e 22 oM RCM ene 241 Shift cte cba ecce eec Tete fe toL Dee 11 22 CM het iste oer bro stades oed tal st ote diu PANE La RRER 32 Draw a constant current 6 Sit Y
56. ollowing keystrokes Key Display V set If you press this key after powering up and there is no currently stored constant voltage value you ll be prompted for the desired voltage level If there was a voltage value already stored it will be momentarily displayed and the instrument will be in CV mode If ou wish to change the voltage setting press V set again The annunciator will be displayed On Off Turns the constant voltage load on The 4 annunciator will be on orv Momentarily display the power level and the set voltage value On Off Turns the load off To operate the DC Load in CV mode in a transient condition see the Transient operation section To operate the DC Load in CV mode in a dynamic condition see the Lists section Constant power mode In constant power mode the DC load will cause a constant power to be dissipated in the load To set up the DC Load to operate in constant power mode and in the steady state condition use the following keystrokes Key Display P set If you press this key after powering up and there is no currently stored constant power value you ll be prompted for the desired 8500 DC Load Series Version February 4 2009 Page 30 of 76 Key Display power level If there was a power value already stored it will be momentarily displayed and the instrument will be in CW mode If you wish to change the power setting press P set ag
57. oltage CV constant power CW or constant resistance CR Notation for tables In the following sections we abbreviate the details of the commands Since the first three bytes of a command are i the constant OxAA ii the instrument address and iii the command we will not show those for each command In addition the 26th byte the checksum will also not be shown The table includes a column for Byte offset This is the zero based index of the byte in the packet Note the offset numbers are in decimal A table entry of Reserved means the data are currently unused or reserved for future use Good programming practice is to set these bytes to 0x00 Some commands require two byte and four byte integers to represent parameter settings These integers are stored in the command packet in little endian format Little endian is a byte ordering format in which bytes with lower addresses have lower significance We will refer to the individual bytes as follows For a two byte integer the least significant byte will be called the low byte and the most significant byte will be called the high byte For a four byte integer we will use the following notation Least significant two bytes least significant byte Lower low byte Least significant two bytes most significant byte Lower high byte Most significant two bytes least significant byte Higher low byte 8500 DC Load Series Version February 4 2009 Page 51 of 76 Most significant t
58. or more details Voltage threshold operation The DC Load can be set to only turn on if the voltage is at or above a set value Additionally the load will turn off if the voltage drops below a second set value This feature works for any mode An example of use would be to ensure an electronic system under test will not have power applied unless the supply voltage is above a certain value The DC Load would be put in series with the power supply Remote sensing would be turned on and the remote sensing connector on the back would be used to connect to the power supply s output voltage Use the menu items SYSTEM SET VOLTAGE ON SET and SYSTEM SET VOLTAGE OFF SET to set the on and off voltage thresholds respectively Example 1 set the VOLTAGE ON SET and SYSTEM SET VOLTAGE OFF SET both to 1 0 V Set the instrument to constant current mode with the I set key and set the current level to 0 1 A Turn the load on by pressing the On Off key When power is applied to the DC Load the voltage must rise above 1 0 V before the load draws current from the source If the voltage drops below 1 0 V on the load s terminals the load will stop drawing current from the source Example 2 Same as the previous example except set the VOLTAGE ON SET to 1 0 V and the SYSTEM SET VOLTAGE OFF SET 0 0 V As before the load will turn on only when the voltage exceeds 1 0 V but once it is triggered on it will now stay on even if the voltage drops to zero
59. oring list steps Byte offset Meaning 3 Partition scheme 1 means 1 file of 1000 list steps 2 means 2 files of 500 list steps 4 means 4 files of 250 list steps 8 means 8 files of 120 list steps 4 24 Reserved C Save the list file Byte offset Meaning 3 Storage location a one byte integer from 1 to 8 This number must be consistent with the number of list files allowed as set by the OX4A command 4 24 Reserved Ox4D Recall the list file Byte offset Meaning 3 Storage location a one byte integer from 1 to 8 4 24 Reserved Ox4E Set minimum voltage in battery testing Byte offset Meaning 3to6 4byte little endian integer specifying the minimum voltage in units of 1 mV 7 24 Reserved Byte Ox4F Read minimum voltage in battery testing Byte 3to6 4 byte little endian integer specifying the minimum voltage in units of 1 mV 8500 DC Load Series Version February 4 2009 Page 63 of 76 Byte offset Meaning 7 24 Reserved 0x50 Set timer value of for LOAD ON Byte 3to4 2 byte little endian integer specifying the time in units of 1 second 5 24 Reserved 0x51 Read timer value for LOAD ON Byte 3to4 2 byte little endian integer specifying the time in units of 1 second 5 24 Reserved 0x52 Disable enable timer for LOAD ON Byte offset Meaning 3 0 is disable timer 1 is enable timer 4 24
60. ove the power cord from the instrument Open the fuse container on the rear panel and check the fuse for continuity If the fuse is an open circuit replace it with the proper fuse indicated in the following table Model Fuse specification for 110 Fuse specification for 220 VAC operation VAC operation 8500 T0 5A 250 VAC T0 3A 250 VAC 8502 T0 5A 250 VAC T0 3A 250 VAC 8510 T0 5A 250 VAC T0 3A 250 VAC 8512 T2 5A 250 VAC T0 1 25A 250 VAC 8514 T2 5A 250 VAC T0 1 25A 250 VAC 8518 T2 5A 250 VAC T0 1 25A 250 VAC 8520 T2 5A 250 VAC T0 1 25A 250 VAC 8522 T2 5A 250 VAC T0 1 25A 250 VAC 8524 T5A 250 VAC T2 5A 250 VAC 8526 T5A 250 VAC T2 5A 250 VAC Ensure that the fuse is rated for 250 VAC operation Lower voltage rated fuses are not suitable for this instrument Error messages during power up EEPROM ERROR means the calibration data have been lost or the EEPROM is not functional ERROR CAL DATA means that the calibration data have been lost If you experience these error messages the instrument should be returned to B amp K Precision for service Keypad unlock procedure Keypad was accidentally locked If you accidentally locked the keyboard follow this procedure to unlock The procedure below shows how to unlock a model 8500 using 8512 as the unlock key 1 Press Shift Menu You will see PASSWORD displayed on the screen Enter 8512 then press the Enter key Now you wi
61. ple Suppose we have a small AC to DC power supply a wall wart and we want to set up an acceptance test for a number of these devices Our test will consist of two steps 1 Set the DC load to constant current mode to draw the rated current of 0 35 A from the device The output voltage of the device at the rated current must be between 4 4 volts and 4 6 volts 2 When the device operates into a short the supplied current must be larger than 2 0 A Keys Display Shift Menu CONFIG vv LIST SE Enter MODE SET vvvv EDIT TEST FILE Enter UAM Sm Set the maximum current to 2 5 A 2 5 Enter WAV ce SERA Set the maximum voltage to 5 V 5 Enter uA Me eA Set the maximum power to 15 W 15 Enter UAM PEERS Our test wil consist of two steps so we enter 2 You can enter up to 20 steps 2 Enter oe Mesi al Since our first test is in constant current mode we ll just press Enter to select this mode Enter SSE At This is the prompt for the constant current value We set it to 0 35 A 35 Enter Siela Rela We can turn a short on or off at this step Here we want short off so we just press Enter Enter S STA A We re being prompted for what parameter to read back and check We want voltage so we press Enter Enter MIN We want the minimum voltage read back to be at least 4 4 V 4 4 Enter WAV GER mE The maximum value we ll allow is 4 6 V 4 6 Enter Pam LEMMA This del
62. pplications include fuel cell and photovoltaic cell test The DC Load can operate under the following modes Draw a constant voltage from a DC source Draw a constant current from a DC source Draw a constant power from a DC source Present a constant resistance to the DC source this behavior simulates a perfect resistor 8500 DC Load Series Version February 4 2009 Page 6 of 76 whose resistance doesn t change as a function of current or voltage The DC Load can present dynamically changing loads to the DC source with millisecond switching times The DC Load can be remotely programmed via a serial interface RS 232 or USB Versatile triggering options allow the dynamic load behavior to be synchronized with other events A battery test mode is provided that will measure the ampere hour A hr characteristic of a battery Shorts can be simulated by either the front panel or custom programming The DC source or other components can be protected from excessive voltage current or power which will cause the DC Load to shut down if excessive levels or reverse polarity are detected Dynamic profiles and last instrument states can be stored in non volatile memory The DC Load is a versatile instrument for static and dynamic testing of power supplies batteries DC to DC converters and battery chargers Typical tasks To perform the following tasks consult the indicated sections Task Section s Manual on off CC CV CW or C
63. r Voltage protection If input voltage exceeds the voltage limit set by the user the DC load will turn the input OFF and the buzzer will sound The display will Show OVER VOLTAGE The maximum voltage limit value is equal to the maximum rated voltage for each model For the over voltage protection state to be activated the voltage level presented to the load terminal must exceed the limit set value by approximately 5 Over Current protection When operating in CR CC or CW mode the load current will be limited by a current limit value set by the user The maximum current limit value is equal to the maximum rated current for each model Once the maximum current limit is reached the DC Load will enter the over current protection state and the current will be limited to the set value The input will not turn off If the DC load previously operated CR or CW mode the DC load will automatically revert to CC mode and the VFD display will indicate CC When the DC load operates in a combined CV transition mode or CV List mode the buzzer will sound if the input current exceeds the current limit and the display will show a flashing current value Over Power protection If the input power exceeds the power limit in the normal operation mode the DC load will enter the over power protection state The display will show CW If the input power exceeds the limit when in transition mode or list mode the buzzer will sound and the display will flash the c
64. rdered in little endian format 0x6A would be the 3 byte Ox3F the 4 byte 0x00 as 5 byte and 0x00 as the 6 byte 0x23 Read the maximum voltage allowed Byte offset Meaning 3 Lower low byte of maximum voltage 1 represents 1 mV 4 Lower high byte of maximum voltage 5 Upper low byte of maximum voltage 6 Upper high byte of maximum voltage 7 24 Reserved 0x24 Set the maximum current allowed Byte offset Meaning 3 Lower low byte of maximum current 1 represents 0 1 mA 4 Lower high byte of maximum current 5 Upper low byte of maximum current 6 Upper high byte of maximum current 7 24 Reserved Example Suppose you want to set the maximum current to 3 12A Since 1 represents 0 1mA 3 12A translates to 31 200 in decimal With 4 bytes in Hex that would be 0x000079EO0 Since the bytes are ordered in little endian format OXEO would be the 3 byte 0x79 the 4 byte 0x00 as 5 byte and 0x00 as the 6 byte 0x25 Read the maximum current allowed Byte 3 Lower low byte of maximum current 1 represents 0 1 mA 4 Lower high byte of maximum current 8500 DC Load Series Version February 4 2009 Page 53 of 76 Byte offset Meaning 5 Upper low byte of maximum current 6 Upper high byte of maximum current 7 24 Reserved 0x26 Set the maximum power allowed Byte offset Meaning 3 Lower low byte of maximum power 1 represent
65. rical keys then press current you want to draw from the battery You may have Enter to press the I set key twice to be able to set the current value Shift Battery UU Ae SEA This indicates you re being asked for the voltage level where the battery test will be over Enter voltage level and press When you press Enter the test will start The Enter annunciator will be on orv Shows the power level and the ampere hours A hrs accumulated so far When the battery voltage drops below the specified value the test will turn off and you will see the sIdglannunciator orv Display the total charge delivered by the battery in ampere hours A hrs Shift Battery Turns battery testing mode off NOTE you must make sure that you press Shift Battery at the end of the test Otherwise the instrument will not respond to any key presses except or v Transient operation The transient condition allows switching between two different load values There are three different types of transient operation Continuous transient operation In continuous transient operation the load is continuously switched between two load values An example is shown in the following figure 2 0ms 3 0ms Continuous Transient Operation Note that this transient behavior works with any of the operation modes CC CV CW or CR Here are the keystrokes used to setup this continuous transient condition Keys Display
66. rnal adjustments must be made only by qualified service personnel Do not replace components with the power cable connected Under certain conditions dangerous voltages may exist even with the power cable removed To avoid injuries always disconnect power discharge circuits and capacitors and remove external voltage sources before touching components DO NOT SERVICE OR ADJUST ALONE Do not try to perform internal service or adjustment unless another person capable of rendering first aid and resuscitation is present Safety Symbols Note the instrument s external markings as follows a Direct current Alternating current Both direct and alternating current Protective earth ground terminal Caution refer to accompanying documents m The WARNING sign denotes a hazard It calls attention to a procedure practice or the like which if not correctly performed or adhered to could result in personal injury Do not proceed beyond a WARNING sign until the indicated conditions are fully understood and met The CAUTION sign denotes a hazard It calls attention to an operating procedure or the like which if not correctly performed or adhered to could CAUTION result in damage to or destruction of part or all of the product Do not proceed beyond a CAUTION sign until the indicated conditions are fully understood and met 8500 DC Load Series Version February 4 2009 Page 2 of 76 Table of
67. rogramming much easier as it does the low level bit manipulation for you Instead of sending a 26 byte string you can send a high level command such as SetMaxCurrent current Example script Set DC load to remote mode import serial length packet 26 Number of bytes in a packet def DumpCommand bytes assert len bytes length packet header 3 print header for i in xrange length packet if i 10 0 and i 0 print print header if i 5 8500 DC Load Series Version February 4 2009 Page 46 of 76 print W W y s 02x ord bytes i if s 00 S chr 250 2 DEINE ey print def CalculateChecksum cmd assert len cmd length packet 1 or len cmd length packet checksum 0 for i in xrange length packet 1 checksum ord cmd il checksum 256 return checksum def main port 3 COM4 for my computer baudrate 38400 sp serial Serial port baudrate Open a serial connection Construct a set to remote command cmd chr 0xaa chr 0x00 chr 0x20 First three bytes cmd chr 0x01 chr 0x00 length_ packet 1 4 cmd chr CalculateChecksum cmd assert len cmd length packet Send command to DC load sp write cmd print Set to remote command DumpCommand cmd Get response from DC load response sp read length packet assert len response length packet print Response DumpCommand response main
68. s please refer to the service and support section on our website Return all merchandise to B amp K Precision Corp with prepaid shipping The flat rate repair charge for Non Warranty Service does not include return shipping Return shipping to locations in North American is included for Warranty Service For overnight shipments and non North American shipping fees please contact B amp K Precision Corp B amp K Precision Corp 22820 Savi Ranch Parkway Yorba Linda CA 92887 www bkprecision com 714 921 9095 Include with the returned instrument your complete return shipping address contact name phone number and description of problem LIMITED ONE YEAR WARRANTY B amp K Precision Corp warrants to the original purchaser that its products and the component parts thereof will be free from defects in workmanship and materials for a period of one year from date of purchase B amp K Precision Corp will without charge repair or replace at its option defective product or component parts Returned product must be accompanied by proof of the purchase date in the form of a sales receipt To obtain warranty coverage in the U S A this product must be registered by completing a warranty registration form on our website www bkprecision com within fifteen 15 days of purchase Exclusions This warranty does not apply in the event of misuse or abuse of the product or as a result of unauthorized alterations or repairs The warranty is v
69. s 1 mW 4 Lower high byte of maximum power 5 Upper low byte of maximum power 6 Upper high byte of maximum power 7 24 Reserved Example Suppose you want to set the maximum power to 213 45W Since 1 represents 1mW 213 45W translates to 213 450 in decimal With 4 bytes in Hex that would be 0x000341CA Since the bytes are ordered in little endian format OXCA would be the 3 byte 0x41 the4 byte 0x03 as 5 byte and 0x00 as the 6 byte 0x27 Read the maximum power allowed Byte offset Meaning 3 Lower low byte of maximum power 1 represents 1 mW 4 Lower high byte of maximum power 5 Upper low byte of maximum power 6 Upper high byte of maximum power 7 24 Reserved 0x28 Set CC CV CW or CR mode Byte offset Meaning 3 Mode 0 is CC 1 is CV 2is CW 3 is CR 4 24 Reserved 0x29 Read the mode being used CC CV CW or CR 8500 DC Load Series Version February 4 2009 Page 54 of 76 Byte offset Meaning 3 Mode 0 is CC 1 is CV 2 is CW 3 is CR 4 24 Reserved 0x2A Set CC mode current Byte offset Meaning 3 Lower low byte of current 1 represents 0 1 mA 4 Lower high byte of current 5 Upper low byte of current 6 Upper high byte of current 7 24 Reseved 0x2B Read CC mode current Byte offset Meaning 3 Lower low byte of current 1 represents
70. s of 0 1 ms Little endian 2 byte number 15 Transient operation 8500 DC Load Series Version February 4 2009 Page 57 of 76 Byte offset Meaning 0 is CONTINUOUS 1 is PULSE 2 is TOGGLED 16 24 Reserved 0x35 Read CV mode transient parameters Byte offset Meaning 3to6 Value A of voltage in units of 1 mV Little endian 4 byte number 7108 Time for A voltage in units of 0 1 ms Little endian 2 byte number 9to 12 Value B of voltage in units of 1 mV Little endian 4 byte number 13 to 14 Time for B voltage in units of 0 1 ms Little endian 2 byte number 15 Transient operation 0 is CONTINUOUS 1 is PULSE 2 is TOGGLED 16 24 Reserved 0x36 Set CW mode transient power and timing Byte offset Meaning 3to6 Value A of power in units of 1 mW Little endian 4 byte number 7to8 Time for A power in units of 0 1 ms Little endian 2 byte number 9to 12 Value B of power in units of 1 mW Little endian 4 byte number 13 to 14 Time for B power in units of 0 1 ms Little endian 2 byte number 15 Transient operation 0 is CONTINUOUS 1 is PULSE 2 is TOGGLED 16 24 Reserved 0x37 Read CW mode transient parameters Byte offset Meaning 3to6 Value A of power in units of 1 mW Little endian 4 byte number 7to8 _ Time for A power in units of 0 1 ms Little endian 2 byte number 9to 12 Value B of power in units of 1 mW Little endian 4 by
71. ssing Shift A The load has to be on and cannot be in transient condition i e the annunciator must not be lit Otherwise the A value will be stored as the CC mode s current Similarly Shift B causes the B value to be stored as the CC mode s current The load can be on or off for this to work Lists dynamic condition Transient operation is used for simple step changes in load values More complicated dynamic behavior of the load can be obtained through the use of lists Lists are a sequence of load value and duration pairs Lists are the logical extension of transient operation To illustrate the use of a list we ll create a list that runs the following constant current profile on a power supply Trigger oi 1 2i 34 5 M Listcounte1 gt lt List count 2 List sequence This list is characterized by the following current duration pairs 8500 DC Load Series Version February 4 2009 Page 36 of 76 Current A Duration ms Between times 3 1000 0 and 1 0 800 1and2 2 500 2 and 3 0 300 3 and 4 6 500 4 and 5 This list has 5 steps located at the transitions 1 through 5 The first duration 1000 ms occurs after the triggered event Subsequent durations are from the previous transition to the current transition Here are the keystrokes to set up this list
72. supply s current to a very low level e g 0 1 A Set the DC Load voltage level well below the supply voltage level e g 1 V Press the On Off key Verify the proper voltage level 1 V is shown on the display Press the or v keys to see the power being dissipated Press the P set button you may have to press it twice Note the load is turned off Set the power level to 0 1 watt Press the On Off key Press the or v keys to verify that the power is about 0 1 8500 DC Load Series Version February 4 2009 Page 27 of 76 watt Press the R set button you may have to press it twice Set the resistance to 100 O Press the On Off key Verify that the current is approximately the displayed voltage in V divided by 100 You can cycle between the four modes by pressing the I set V set P set and R set buttons Note that the previously set values are remembered If the instrument worked as explained above you ve demonstrated that the four operating modes of the instrument are working Please refer to the next section for detailed operation instructions Operational introduction There are four operational modes of the instrument constant current constant voltage constant power and constant resistance we will abbreviate these as CC CV CW and CR respectively These are selected by the I set V set P set and R set buttons respectively If you press a mode button different than the currently set mode the load will be set to 27959 an
73. te number 13 to 14 Time for B power in units of 0 1 ms Little endian 2 byte number 8500 DC Load Series Version February 4 2009 Page 58 of 76 Byte offset Meaning 15 Transient operation 0 is CONTINUOUS 1 is PULSE 2 is TOGGLED 16 24 Reserved 0x38 Set CR mode transient resistance and timing Byte offset Meaning 3Qto6 Value A of resistance in units of 1 Q Little endian 4 byte number 7to8 Time for A resistance in units of 0 1 ms Little endian 2 byte number 9to 12 Value B of resistance in units of 1 Q Little endian 4 byte number 13 to 14 Time for B resistance in units of 0 1 ms Little endian 2 byte number 15 Transient operation 0 is CONTINUOUS 1 is PULSE 2 is TOGGLED 16 24 Reserved 0x39 Read CR mode transient parameters Byte offset Meaning 3Qto6 Value A of resistance in units of 1 Q Little endian 4 byte number 7t08 Time for A resistance in units of 0 1 ms Little endian 2 byte number 9to 12 Value B of resistance in units of 1 Q Little endian 4 byte number 13 to 14 Time for B resistance in units of 0 1 ms Little endian 2 byte number 15 Transient operation 0 is CONTINUOUS 1 is PULSE 2 is TOGGLED 16 24 Reserved Ox3A Select the list operation CC CV CW CR Byte offset Meaning 3 List operation mode 0 is constant current CC 1 is constant voltage CV 2 is constant power CW 8500 DC Load Series Vers
74. trokes Key Display Shift Menu Enter Y Y Enter NA Enter Esc CONFIG Esc Standard voltage current display Constant current mode In constant current mode the DC load will sink a constant current regardless of the voltage at its terminals To set up the DC Load to operate in constant current mode and in the steady state condition use the following keystrokes 8500 DC Load Series Version February 4 2009 Page 29 of 76 Key Display l set If you press this key after powering up and there is no currently stored constant current value you ll be prompted for the desired current level If there was a current value already stored it will be momentarily displayed and the instrument will be in CC mode If you wish to change the current setting press I set again The annunciator will be displayed On Off Turns the constant current load on The annunciator will be on orv Momentarily display the power level and the set current value On Off Turns the load off To operate the DC Load in CC mode in a transient condition see the Transient operation section To operate the DC Load in CC mode in a dynamic condition see the Lists section Constant voltage mode In constant voltage mode the DC load will cause a constant voltage to appear at its terminals To set up the DC Load to operate in constant voltage mode and in the steady state condition use the f
75. ur bd cubana eK C MENU RUE FEE 42 Saving and Recalling SSM oO OTT OTT 43 Remote ODOTFALlOri 225 eor ciune reap Eran a tropa ka pt cRU dea aeta E eo Dk ue hs rU kd AAE AEREA AE DA TERR EARR dA KE a ERR CRI SR EAE 44 Communication Cables e um e eee tret e deer te de eee de vehe bete NINENA ye VEENAS NAAI cree Eee Creta ege ru ev bei sed 44 RS232 to TTL serial converter cable IT 131 standardi 44 USB to TTL serial converter cable 11 132 Opti yes ses niano e trn khoa xa me sEanbo e ruun 44 Siem EP DS NEN DOE RE 45 Overview of DC Load programming sss see eee 45 PACKER SURI HUE uec oeste ecco te ete he eee E exe ode Lan nie aee tee des edet eder need eden 45 Stas PACK GUS 7 5 6 EET PM M 46 Chapter orgatilzatiorni oneri re tee er er e E E YR VR ENEE A y ek ETO a 48 Summary f cO Tnts iiciin RE AER Ne UE FERAE Fe Ben e aA SORA oamtdeeauaoaseanadcedenetereasswcevenaeancaadenes 49 Lo eR TRUE ULL La SES LS RETRO 51 Serial number and firmware VersloD deiecit eene ses esee ree hr nanna nnan ex ctu iulfif rema iiixt i fexgWe xe take eases 71 Incase of Tei men a ne ee ene ue Det 72 insiument wont TUR OD caeco eee Sees an ciao yak area Eo ee ee eon SNL ECESANTA REETA EAEN ARANAN ANa tele Tae eeu eere ds 72 Error messages during pDOWE UD ice icio tue xen rotto eue tien aini Eens En r NENE NE EENEN KATSON ETNEA TEE 72 Keypad unlock procedure Keypad was accidentally locked 72 Appendix Service and warranty Information 74 Ws eee
76. urrent value and voltage value Reverse voltage protection This feature protects the load module in case the DC input terminals are connected to a power source with reversed polarity If a reverse voltage condition is detected the buzzer will sound and REVERSE VOLTAGE will be displayed on screen 8500 DC Load Series Version February 4 2009 Page 41 of 76 Over Temperature protection If internal temperature exceeds safety limits 80 C 176 F the Over temperature circuitry will be activated The DC Load will turn off the input the buzzer will sound and the display will show OVERHEAT Remote sensing Remote sensing is used to counteract the effect of lead resistance For example if you connect a power supply to the DC Load the voltage at the power supply s terminals will not be the same as the voltage at the DC Load s terminals if there is a current flowing because of the finite resistance from the wires Using remote sensing you can sense the voltage at the power supply s terminals effectively removing the effect of the voltage drop in the connection wire When using remote sensing the power displayed by the instrument includes both the power dissipated inside the instrument and the power dissipated in the leads from the power supply to the DC Load s input terminals To turn remote sensing on Keys Display Shift Menu Enter v 8 times Enter Y ON Enter and annunciator shows Sense Esc Esc Exit
77. wo bytes most significant byte As an example for the integer 0xX23A749F5 we d have Higher high byte 1st byte OxF5 Lower low byte 2nd byte 0x49 Lower high byte 3rd byte 0xA7 Higher low byte Ath byte 0x23 Higher high byte 0x12 Indicates a return packet for a command sent to the DC Load Byte 3 Status byte i e status of last command sent to DC Load 4 24 Reserved Below is a table of all possible status byte values and their corresponding indication 0x90 Checksum incorrect OxAO Parameter incorrect OxBO Unrecognized command 0xCO Invalid command 0x80 Command was successful 0x20 Setthe DC Load to remote operation Byte offset Meaning 3 0 means front panel operation 1 means remote operation 4 24 Reserved 0x21 Turn the load ON or OFF Byte offset Meaning 3 0 is OFF 1 is ON 4 24 Reserved 0x22 Setthe maximum voltage allowed Byte offset Meaning 3 Lower low byte of maximum voltage 1 represents 1 mV 4 Lower high byte of maximum voltage 8500 DC Load Series Version February 4 2009 Page 52 of 76 Byte 5 Upper low byte of maximum voltage 6 Upper high byte of maximum voltage 7 24 Reserved Example Suppose you want to set the maximum voltage to 16 23V Since 1 represents 1mV therefore 16 23V translates to 16 230 in decimal With 4 bytes in Hex that would be 0x0003F6A Since the bytes are o
78. you will have different types and numbers of input terminals Models 8500 8502 come with one plus and one minus terminal Models 8510 8512 come with two positive and two negative terminals however each terminal is able to sink the maximum current supported by the instrument Thus it is not necessary to double up on the wires when sinking a high current unless you wish to Models 8514 8518 also come with two positive and two negative terminals however it is required to double up on the wires when sinking a current exceeding 120A s Models 852x come with a screw terminal block to connect the wires 8500 DC Load Series Version February 4 2009 Page 8 of 76 Standard display The standard display for the instrument is the voltage and current at the instrument s terminals You may press the or v keys to see the instantaneous power and the mode s parameter setting Standard display BK PRECISION 8500 300W Programmable DC Electronic Load Front panel keys D 2 3 esc L I set_ V set ran B Tran CP set R set ENTER Store Recall S Tran Menu C Shift nput onlof A Local Battery Short Trigger Set the current mode s load value from the A value of the corresponding transient operation See the Transient operation section This key does not work when the annunciator is on Shift A Set the current mode s load value from the B value
79. yte little endian integer specifying which step number in the list 5to8 4 byte little endian integer specifying the current in units of 0 1 mA 9to 10 2 byte little endian integer specifying the step timing in units of 0 1 ms 11 24 Reserved 0x42 Setone of the step s voltage and time values Byte offset Meaning 3to4 2 byte little endian integer specifying which step number in the list 5108 4byte little endian integer specifying the voltage in units of 1 mV 9to 10 2 byte little endian integer specifying the step timing in units of 0 1 ms 11 24 Reserved 0x43 Read one of the step s voltage and time values Byte offset Meaning 3to4 2 byte little endian integer specifying which step number in the list 5108 4byte little endian integer specifying the voltage in units of 1 mV 9to 10 2 byte little endian integer specifying the step timing in units of 0 1 ms 11 24 Reserved 0x44 Set one of the step s power and time values Byte offset Meaning 3to4 2 byte little endian integer specifying which step number in the list 5t08 4byte little endian integer specifying the power in units of 1 mW 9to 10 2 byte little endian integer specifying the step timing in units of 0 1 ms 11 24 Reserved 8500 DC Load Series Version February 4 2009 Page 61 of 76 0x45 Set one of the step s power and time values 0x4 Byte offset Meaning 3to4 2 byte little

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