CALIBRATION PROCEDURE SCXI -1100 ™ This document contains step-by-step instructions for verifying the performance of National Instruments SCXI-1100 modules. Equipment and Other Test Requirements This section describes the equipment, software, documentation, and test conditions required for verifying the performance of the SCXI-1100. Test Equipment Verification requires a high-precision voltage source with at least 50 ppm accuracy and an E Series data acquisition (DAQ) device. NI recommends you use the following instruments for verifying the performance of the SCXI-1100: • Calibrator—Fluke 5700A • National Instruments E Series DAQ device If these instruments are not available, use the accuracy requirements listed above to select a substitute calibration standard. Notes If you do not have custom connection hardware, you need a connector block such as the National Instruments SCXI-1300, a shielded 68-pin connector cable, and an SCXI-1349 adapter. These components give easy access to the individual pins on the SCXI-1100 front and rear connectors. Do not use an SCXI-1308 terminal block as the current sensing resistors causes false failures. Software and Documentation This section describes the software and documentation required for verifying the performance of the SCXI-1100 module. Software The only software required for this verification procedure is the current version of NI-DAQ, which contains the required calibration functions. Documentation This calibration document contains all the information you need to complete the verification procedure. If you want more information about the product, refer to the SCXI-1100 User Manual, which you can download from ni.com/manuals. If you need more information about the calibration functions, refer to the NI-DAQ Function Reference Help, which you can find by selecting Start»Programs»National Instruments» NI-DAQ»NI-DAQ Help»NI-DAQ Function Reference Help. Test Conditions Follow these guidelines to optimize the connection and the environment during verification. • Keep connections to the SCXI module as short as possible. Long cables and wires act as antennae, picking up extra noise that can affect measurements. • Use shielded copper wire for all cable connections to the module. Use twisted-pair wire to eliminate noise and thermal offsets. • Maintain temperature between 18 and 28 °C. • Keep relative humidity below 80%. • Allow a warm-up time of at least 15 minutes for the SCXI module and 30 minutes for the E Series DAQ device to ensure the measurement circuitry is at a stable operating temperature. Verification Procedures The SCXI-1100 does not maintain user-adjustable calibration constants, so you can only verify the performance of the module. Setting Up the Module Complete the following steps to set up the SCXI-1100 for testing. SCXI-1100 Calibration Procedure 1. Install the SCXI-1100 in slot 1 of the SCXI chassis. 2. Using an SCXI-1349 cable adapter, connect a 68-to-68-pin cable between the SCXI-1100 module and the E Series DAQ device installed in the host computer, as shown in Figure 1. 2 ni.com 8 1 7 2 ® 5 4 3 2 1 ADDRESS 3 6 SC XI 11 00 4 5 1 2 3 4 E Series DAQ Device SH68-68 Cable SCXI-1349 Cable Adapter Thumbscrews 5 6 7 8 SCXI-1100 Module SCXI Terminal Block SCXI Chassis Power Switch SCXI-1000 Chassis Figure 1. Connecting an SCXI Chassis to an E Series DAQ Device 3. Configure the hardware with Measurement & Automation Explorer (MAX). If you need more information on configuring the system, refer to the E Series DAQ device and SCXI-1100 documentation, which is available at ni.com/manuals. 4. Set all jumpers to their factory-default settings, as shown in Table 1. © National Instruments Corporation 3 SCXI-1100 Calibration Procedure Table 1. Factory-Default Jumper Settings Jumper W1 Description Configuration Factory setting; parking position (used for ground-referenced sources) W5 Factory setting; connects MISO to SERDATOUT W6 Factory setting; do not remove this jumper W7 Factory setting; parking position. Disconnects the front connector from the module output W8 Factory setting; parking position 1 2 3 R0 R1 R2 W9 Factory setting; connects pull-up resistor to SERDATOUT (revision C and later modules only) R0 R1 R2 W10 Factory setting; parking position (used with E Series devices in differential mode) R0 R1 R2 W11 Factory setting (revisions A and B only) R0 R1 R2 SCXI-1100 Calibration Procedure 4 ni.com The SCXI-1100 module has jumpers that you can use to change the filter settings, as shown in Table 2. During the verification procedure, you need to change the filter settings to verify both the 4 Hz and 10 kHz measurement accuracies. You can change the filter settings without powering off the SCXI chassis. Table 2. Jumper Filter Settings Jumper W2 Description Configuration Factory setting is full bandwidth (FBW) and no filtering W3 10 kHz lowpass filter W4 4 Hz lowpass filter 1 2 3 Verifying the Performance of the Module The verification procedure determines how well the SCXI-1100 module is meeting its specifications. You can use this information to select the appropriate calibration interval for your application. All calibration functions are contained in nidaq32.dll. For more information on these functions, refer to the NI-DAQ Function Reference Help, which is available at ni.com/manuals. Note Complete the following steps to verify the performance of the SCXI-1100. 1. Read the Test Conditions section. 2. Refer to the Uncalibrated Offset Limit and Table 4 for the specification limits to test. NI recommends that you verify all ranges and gains, but you can save time by checking only those ranges used in your application. Channel 0 is the only channel requiring verification because the SCXI-1100 module only contains one instrumentation amplifier. 3. Ensure that the E Series DAQ device is connected to the SCXI-1100. NI recommends that you calibrate only the module that is connected to the E Series DAQ device. Do not calibrate the module in multiplexed mode. Note © National Instruments Corporation 5 SCXI-1100 Calibration Procedure 4. 5. Call Calibrate_E_Series to minimize the uncertainty associated with the E Series DAQ device. Set the following parameters: • deviceNumber = The device number assigned by MAX • calOp = ND_SELF_CALIBRATE (32700) • setOfCalConst = ND_USER_EEPROM_AREA (37000) • calRefVolts = 0.0 Call MIO_Config to enable dithering on the E Series DAQ device measurements. Set the following parameters: • deviceNumber = The device number assigned by MAX • dither = 1 • useAMUX = 0 6. Configure the module jumpers for the 4 Hz filter, as shown in Table 2. 7. Call SCXI_Calibrate_Setup. Set the following parameters: 8. 9. • chassisID = The value assigned by MAX • moduleSlot = 1 • calOp = 1 Call SCXI_Single_Chan_Setup to configure the module for single channel measurements. Set the following parameters: • chassisID = The value assigned by MAX • moduleSlot = 1 • moduleChan = 0 • DAQdeviceNumber = The device number for the E Series DAQ device, which is assigned by MAX Call SCXI_Set_Gain to configure the module to the gain value you are testing. Set the following parameters: • chassisID = The value assigned by MAX • moduleSlot = 1 • moduleChan = –1 • gain = The gain value you are testing from Table 4 10. Wait 30 seconds for the input to settle. SCXI-1100 Calibration Procedure 6 ni.com 11. Call DAQ_Op. Set the following parameters: • deviceNumber = The device number assigned by MAX • channel = 0 • gain = 1 for a 16-bit E Series DAQ device or –1 for a 12-bit E Series DAQ device • count = 100 • sampleRate = 100 12. Call SCXI_Scale to convert the reading from binary to voltage. Set the following parameters: • chassisID = The value assigned by MAX • moduleSlot = 1 • channel = 0 • SCXIgain = The gain you are testing • TBgain = 1 • DAQboard = The device number for the E Series DAQ device • DAQChannel = 0 • DAQgain = 1 • numPoints = 100 • binArray = The array returned from the DAQ_Op Average the results and compare this value to the offset limits in the Uncalibrated Offset Limit section. 13. Configure the module jumpers for the filter you are testing, as shown in Tables 1 and 2. 14. Call SCXI_Calibrate_Setup. Set the following parameters: • chassisID = The value assigned by MAX • moduleSlot = 1 • calOp = 1 15. Call SCXI_Single_Chan_Setup to configure the module for single channel measurements. Set the following parameters: © National Instruments Corporation • chassisID = The value assigned by MAX • moduleSlot = 1 • moduleChan = 0 • DAQdeviceNumber = The device number for the E Series DAQ device, which is assigned by MAX 7 SCXI-1100 Calibration Procedure 16. Call SCXI_Set_Gain to configure the module to the gain value you are testing. Set the following parameters: • chassisID = The value assigned by MAX • moduleSlot = 1 • moduleChan = –1 • gain = The gain value you are testing from Table 4 17. Wait for input to settle (1 s if you are testing the 4 Hz filter, 10 ms if you are testing the 10 kHz filter). 18. Call DAQ_Op. Set the following parameters: • deviceNumber = The device number assigned by MAX • channel = 0 • gain = 1 for a 16-bit E Series DAQ device or –1 for a 12-bit E Series DAQ device • count = 100 • sampleRate = 100 19. Call SCXI_Scale to convert the reading from binary to voltage. Set the following parameters: • chassisID = The value assigned by MAX • moduleSlot = 1 • channel = 0 • SCXIgain = The gain you are testing • TBgain = 1 • DAQboard = The device number for the E Series DAQ device • DAQChannel = 0 • DAQgain = 1 • numPoints = 100 • binArray = The array returned from the DAQ_Op Average the results and save the average for later calculations. This value is the zero offset that you subtract from subsequent measurements. 20. Call SCXI_Calibrate_Setup. Set the following parameters: SCXI-1100 Calibration Procedure • chassisID = The value assigned by MAX • moduleSlot = 1 • calOp = 0 8 ni.com 21. Call SCXI_Single_Chan_Setup to configure the module for single channel measurements. Set the following parameters: • chassisID = The value assigned by MAX • moduleSlot = 1 • moduleChan = 0 • DAQdeviceNumber = The device number for the E Series DAQ device, which is assigned by MAX 22. Call SCXI_Set_Gain to configure the module to the gain value you are testing. Set the following parameters: • chassisID = The value assigned by MAX • moduleSlot = 1 • moduleChan = –1 • gain = The gain value you are testing from Table 4 23. Input the test voltage listed in Table 4 into Channel 0 of the SCXI-1100 module. 24. Wait for input to settle (1 s if you are testing the 4 Hz filter, 10 ms if you are testing the 10 kHz filter). 25. Call DAQ_Op. Set the following parameters: • deviceNumber = The device number assigned by MAX • channel = 0 • gain = 1 for a 16-bit E Series DAQ device or –1 for a 12-bit E Series DAQ device • count = 100 • sampleRate = 100 26. Call SCXI_Scale to convert the reading from binary to voltage. Set the following parameters: © National Instruments Corporation • chassisID = The value assigned by MAX • moduleSlot = 1 • channel = 0 • SCXIgain = The gain you are testing • TBgain = 1 • DAQboard = The device number for the E Series DAQ device • DAQChannel = 0 • DAQgain = 1 9 SCXI-1100 Calibration Procedure • numPoints = 100 • binArray = The array returned from the DAQ_Op The result is a set of scaled voltages you read from the SCXI-1100 module. 27. Average the results returned from the SCXI_Scale. Subtract the zero offset that you calculated in step 12 from this averaged value. Compare the result to the upper and lower limits in Table 4. 28. Repeat steps 14 through 27 for the remaining test points and gains. 29. Repeat steps 6 through 28 for the remaining filter settings. You have finished verifying the performance of the SCXI-1100 module. If the module fails to meet its required specifications, contact NI for repair or replacement. Front and Rear Connector Pin Assignments Table 3 shows the pin assignments for the SCXI-1100 module front signal connector. Figure 2 shows the pin assignments for the SCXI-1100 rear signal connector. SCXI-1100 Calibration Procedure 10 ni.com Table 3. Front Signal Pin Assignments Front Connector Diagram Pin Number Column A Column B Column C 32 CGND CH0– CH0+ 31 NC CH1– CH1+ 30 NC CH2– CH2+ 29 NC CH3– CH3+ 28 NC CH4– CH4+ 27 NC CH5– CH5+ 28 26 NC CH6– CH6+ 27 25 NC CH7– CH7+ 24 CGND CH8– CH8+ 23 NC CH9– CH9+ 23 22 NC CH10– CH10+ 22 21 NC CH11– CH11+ 21 20 NC CH12– CH12+ 19 NC CH13– CH13+ 18 18 NC CH14– CH14+ 17 17 NC CH15– CH15+ 16 16 CGND CH16– CH16+ 15 NC CH17– CH17+ 14 NC CH18– CH18+ 12 13 NC CH19– CH19+ 11 12 NC CH20– CH20+ 11 NC CH21– CH21+ 10 NC CH22– CH22+ 7 9 NC CH23– CH23+ 6 8 OUTPUT CH24– CH24+ 5 7 AOREF CH25– CH25+ 6 GUARD CH26– CH26+ 2 5 CGND CH27– CH27+ 1 4 DTEMP CH28– CH28+ 3 MTEMP CH29– CH29+ 2 CGND CH30– CH30+ 1 +5V CH31– CH31+ A Column B C 32 31 30 29 26 25 24 20 19 15 14 13 10 9 8 4 3 Note: NC means no connection. © National Instruments Corporation 11 SCXI-1100 Calibration Procedure AO GND CH0+ OUT REF SER DAT IN DAQ D*/A SLOT 0 SEL DIG GND SER CLK RSVD 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 AO GND CH0– DIG GND SER DAT OUT AI HOLD RSVD Figure 2. SCXI-1100 Rear Connector Pin Assignments Specifications This section contains test specifications for the SCXI-1100 module. The test point value should fall between the upper limit and lower limit values. Uncalibrated Offset Limit Gain ........................................................1 Filter........................................................4 Hz Offset ......................................................±(3 mV + E Series DAQ device offset) SCXI-1100 Calibration Procedure 12 ni.com Table 4. SCXI-1100 Filter Specifications 4 Hz Filter Test Point (V) Gain Range (V) 1 10.000 9.5000 9.505015 9.494985 9.505015 9.494985 1 10.000 0.0000 0.000265 –0.000265 0.000265 –0.000265 1 10.000 –9.5000 –9.494985 –9.505015 –9.494985 –9.505015 2 5.000 4.5000 4.506940 4.493060 4.506940 4.493060 2 5.000 0.0000 0.000190 –0.000190 0.000190 –0.000190 2 5.000 –4.5000 –4.493060 –4.506940 –4.493060 –4.506940 5 2.000 1.9000 1.902965 1.897035 1.902965 1.897035 5 2.000 0.0000 0.000115 –0.000115 0.000115 –0.000115 5 2.000 –1.9000 –1.897035 –1.902965 –1.897035 –1.902965 10 1.000 0.9500 0.951510 0.948490 0.951511 0.948489 10 1.000 0.0000 0.000085 –0.000085 0.000086 –0.000086 10 1.000 –0.9500 –0.948490 –0.951510 –0.948489 –0.951511 20 0.500 0.4500 0.450750 0.449250 0.450751 0.449249 20 0.500 0.0000 0.000075 –0.000075 0.000076 –0.000076 20 0.500 –0.4500 –0.449250 –0.450750 –0.449249 –0.450751 50 0.200 0.1900 0.190345 0.189655 0.190346 0.189654 50 0.200 0.0000 0.000060 –0.000060 0.000061 –0.000061 50 0.200 –0.1900 –0.189655 –0.190345 –0.189654 –0.190346 100 0.100 0.0950 0.095198 0.094803 0.095199 0.094802 100 0.100 0.0000 0.000055 –0.000055 0.000056 –0.000056 100 0.100 –0.0950 –0.094803 –0.095198 –0.094802 –0.095199 200 0.050 0.0450 0.045123 0.044878 0.045124 0.044877 200 0.050 0.0000 0.000055 –0.000055 0.000056 –0.000056 200 0.050 –0.0450 –0.044878 –0.045123 –0.044877 –0.045124 500 0.020 0.0190 0.019079 0.018922 0.019080 0.018921 500 0.020 0.0000 0.000050 –0.000050 0.000051 –0.000051 © National Instruments Corporation Upper Limit (V) 13 Lower Limit (V) 10 kHz Filter Upper Limit (V) Lower Limit (V) SCXI-1100 Calibration Procedure Table 4. SCXI-1100 Filter Specifications (Continued) 4 Hz Filter Test Point (V) Upper Limit (V) Lower Limit (V) 10 kHz Filter Gain Range (V) 500 0.020 –0.0190 –0.018922 –0.019079 –0.018921 –0.019080 1000 0.010 0.0095 0.009560 0.009440 0.009561 0.009439 1000 0.010 0.0000 0.000046 –0.000046 0.000047 –0.000047 1000 0.010 –0.0095 –0.009440 –0.009560 –0.009439 –0.009561 2000 0.005 0.0045 0.004552 0.004448 0.004553 0.004447 2000 0.005 0.0000 0.000046 –0.000046 0.000047 –0.000047 2000 0.005 –0.0045 –0.004448 –0.004552 –0.004447 –0.004553 National Instruments™, NI™, ni.com™, NI-DAQ™, and SCXI™ are trademarks of National Instruments Corporation. Product and company names mentioned herein are trademarks or trade names of their respective companies. For patents covering National Instruments products, refer to the appropriate location: Help»Patents in your software, the patents.txt file on your CD, or ni.com/patents. © 2000–2003 National Instruments Corp. All rights reserved. Upper Limit (V) Lower Limit (V) *370155D-01* 370155D-01 Sep03