Model 2701 Ethernet-Based DMM / Data Acquisition System Service Manual A GREATER MEASURE OF CONFIDENCE
WARRANTY Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 3 years from date of shipment. Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes, and documentation. During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.
Title Page.fm Page 1 Thursday, July 11, 2002 8:47 PM Model 2701 Ethernet-Based DMM / Data Acquisition System Service Manual ©2002, Keithley Instruments, Inc. All rights reserved. Cleveland, Ohio, U.S.A. First Printing, June 2002 Document Number: 2701-902-01 Rev.
Manual Print History The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The Revision Level letter increases alphabetically as the manual undergoes subsequent updates. Addenda, which are released between Revisions, contain important change information that the user should incorporate immediately into the manual. Addenda are numbered sequentially.
Safety Precautions The following safety precautions should be observed before using this product and any associated instrumentation. Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous conditions may be present. This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury.
bles or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers. Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the voltage being measured.
Table of Contents 1 Performance Verification Introduction ................................................................................ 1-2 Verification test requirements ..................................................... 1-3 Environmental conditions ................................................... 1-3 Warm-up period .................................................................. 1-3 Line power ..........................................................................
Comprehensive calibration ......................................................... 2-5 Calibration cycle .................................................................. 2-5 Recommended equipment ................................................... 2-5 Aborting calibration ............................................................ 2-6 Front panel calibration ........................................................ 2-6 Remote calibration ............................................................
Troubleshooting ....................................................................... Display board checks ........................................................ Power supply checks ......................................................... Digital circuitry checks ..................................................... Analog signal switching states .......................................... 5 4-13 4-13 4-13 4-14 4-14 Disassembly Introduction ............................................................
Optimizing measurement speed ................................................ A-5 DC voltage, DC current, and resistance: ............................ A-5 AC voltage and AC current: ............................................... A-5 Temperature: ....................................................................... A-5 B Calibration Reference Introduction ............................................................................... B-2 Command summary ..................................................
Model 7700 calibration commands ......................................... :CODE .............................................................................. :COUNt? .......................................................................... :DATE? ............................................................................. :INIT ................................................................................ :LOCK .............................................................................. :LOCK? ......
List of Illustrations 1 Performance Verification Figure 1-1 Figure 1-2 Figure 1-3 Figure 1-4 Figure 1-5 Figure 1-15 Figure 1-16 Connections for Model 2701 DC volts verification ............... 1-8 Connections for Model 2701 AC volts verification .............. 1-10 Connections for Model 2701 DC current verification .......... 1-12 Connections for Model 2701 AC current verification .......... 1-13 Connections for Model 2701 resistance verification (100ΩΩ to 10MΩ ranges) ..................................
List of Tables 1 Performance Verification Table 1-1 Table 1-2 Table 1-3 Table 1-4 Table 1-5 Table 1-6 Table 1-7 Table 1-8 Table 1-9 Table 1-10 Table 1-11 Table 1-12 Table 1-13 Table 1-14 Recommended verification equipment .................................. 1-4 DCV reading limits ................................................................ 1-9 ACV reading limits .............................................................. 1-11 DCI limits ..............................................................
4 Troubleshooting Table 4-1 Table 4-2 Table 4-3 Table 4-4 Table 4-5 Table 4-6 Table 4-8 Table 4-7 Table 4-10 Table 4-11 Table 4-9 Table 4-13 Table 4-14 Table 4-12 Table 4-16 Table 4-17 Table 4-15 Table 4-18 Flash memory failure modes .................................................. 4-3 Power supply components ...................................................... 4-6 Display board checks ........................................................... 4-13 Power supply checks ...............................
1 Performance Verification
1-2 Performance Verification Model 2701 Service Manual Introduction Use the procedures in this section to verify that Model 2701 Ethernet Multimeter/Data Acquisition System accuracy is within the limits stated in the instrument’s one-year accuracy specifications. You can perform these verification procedures: • • • Upon receiving the instrument, make sure it was not damaged during shipment and the unit meets factory specifications. If the instrument’s accuracy is questionable. Following calibration.
Model 2701 Service Manual Performance Verification 1-3 Verification test requirements Be sure that you perform the verification tests: • • • • • Under the proper environmental conditions. After the specified warm-up period. Using the correct line voltage. Using the proper calibration equipment. Using the specified reading limits. Environmental conditions Conduct your performance verification procedures in a test environment that has: • • An ambient temperature of 18° to 28°C (65° to 82°F).
1-4 Performance Verification Model 2701 Service Manual Recommended test equipment Table 1-1 summarizes recommended verification equipment. You can use alternate equipment as long as that equipment has specifications at least as good as those listed in Table 1-1. Keep in mind, however, that calibrator uncertainty will add to the uncertainty of each measurement. Table 1-1 Recommended verification equipment Fluke 5700A Calibrator: DC voltage AC voltage (1kHz, 50kHz) 100mV ±14ppm 1.
Model 2701 Service Manual Performance Verification 1-5 Verification limits The verification limits stated in this section have been calculated using only the Model 2701 one-year accuracy specifications, and they do not include test equipment uncertainty. If a particular measurement falls slightly outside the allowable range, recalculate new limits based on both Model 2701 specifications and pertinent calibration equipment specifications.
1-6 Performance Verification Model 2701 Service Manual Performing the verification test procedures Verification test summary Verification tests can be performed either through the Model 2701 front panel terminals or through plug-in modules. This section contains the following procedures: • • Model 2701 verification — Use this procedure to test Model 2701 accuracy through the front panel terminals.
Model 2701 Service Manual Performance Verification 1-7 Test considerations When performing the verification procedures: • • • • • Be sure to restore factory defaults as outlined above. Make sure that the equipment is properly warmed up and connected to the correct input terminals. Also, make sure that the INPUTS switch is in the correct position. Do not use autoranging for any verification tests, because autorange hysteresis may cause the Model 2701 to be on an incorrect range.
1-8 Performance Verification Model 2701 Service Manual Model 2701 verification Perform these tests to verify accuracy using the Model 2701 front panel terminals. Verifying DC voltage Check DC voltage accuracy by applying accurate voltages from the DC voltage calibrator to the Model 2701 INPUT jacks and verifying that the displayed readings fall within specified limits. CAUTION Do not exceed 1000V peak between front terminals INPUT HI and INPUT LO because instrument damage may occur.
Model 2701 Service Manual 2. 3. 4. 5. Performance Verification 1-9 Select the DC volts function by pressing the DCV key and set the Model 2701 to the 100mV range. Set the calibrator output to 0.00000mV DC and allow the reading to settle. Enable the Model 2701 REL mode. Leave REL enabled for the remainder of the DC volts verification tests. Source positive and negative and full-scale voltages for each of the ranges listed in Table 1-2.
1-10 Performance Verification Model 2701 Service Manual Verifying AC voltage Check AC voltage accuracy by applying accurate AC voltages at specific frequencies from the AC voltage calibrator to the Model 2701 inputs and verifying that the displayed readings fall within specified ranges. CAUTION Do not exceed 1000V peak between front terminals INPUT HI and INPUT LO, or 8 × 107 V•Hz input, because instrument damage may occur. Follow these steps to verify AC voltage accuracy: 1.
Model 2701 Service Manual 2. 3. 4. Performance Verification 1-11 Select the AC volts function by pressing the ACV key. Set the Model 2701 for the 100mV range; make sure that REL is disabled. Source 1kHz and 50kHz AC voltages for each of the ranges summarized in Table 1-3 and make sure that the respective Model 2701 readings fall within stated limits.
1-12 Performance Verification Model 2701 Service Manual Verifying DC current Check DC current accuracy by applying accurate DC currents from the DC current calibrator to the AMPS input of the Model 2701 and verifying that the displayed readings fall within specified limits. Follow these steps to verify DC current accuracy: 1. Connect the Model 2701 AMPS and INPUT LO jacks to the calibrator as shown in Figure 1-3. Be sure the INPUTS switch is in the FRONT position.
Model 2701 Service Manual Performance Verification 1-13 Verifying AC current Check AC current accuracy by applying accurate AC voltage current at specific frequencies from the AC current calibrator to the Model 2701 input, verifying that the displayed readings fall within specified limits. Follow these steps to verify AC current. 1. Connect the Model 2701 AMPS and INPUT LO jacks to the calibrator as shown in Figure 1-4. Be sure the INPUTS switch is in the FRONT position.
1-14 Performance Verification Model 2701 Service Manual Verifying resistance Check resistance by connecting accurate resistance values to the Model 2701 and verifying that its resistance readings are within the specified limits. CAUTION Do not apply more than 1000V peak between front terminals INPUT HI and LO or more than 350V peak between SENSE HI and LO, or instrument damage could occur. Follow these steps to verify resistance accuracy: 1.
Model 2701 Service Manual 6. Performance Verification 1-15 Source the nominal full-scale resistance values for the 100Ω-10MΩ ranges summarized in Table 1-6 and verify that the readings are within calculated limits. Connect the Model 2701 INPUT and SENSE jacks to the calibrator as shown in Figure 1-6. Disable external sense on the calibrator. Set the Model 2701 for the 100MΩ range. Source a nominal 100MΩ resistance value and verify that the reading is within calculated limits for the 100MΩ range. 7. 8.
1-16 Performance Verification Model 2701 Service Manual Verifying temperature Thermocouple, thermistor, and RTD temperature readings are derived from DC volts and resistance measurements respectively. For that reason, it is not necessary to independently verify the accuracy of temperature measurements. As long as the DC volts and resistance functions meet or exceed specifications, temperature function accuracy is automatically verified.
Model 2701 Service Manual Performance Verification 1-17 RTD temperature 1. 2. 3. 4. Connect the precision decade resistance box (listed in Table 1-1) to the Model 2701 INPUT and SENSE jacks using four-wire connections. (See Figure 1-5 for similar connecting scheme.) Be sure the INPUTS switch is in the FRONT position. Configure the Model 2701 temperature function for °C units and RTD temperature sensor (α=0.00385) as follows: a.
1-18 Performance Verification Model 2701 Service Manual Verifying frequency Follow the steps below to verify the Model 2701 frequency function: 1. Connect the function generator to the Model 2701 INPUT jacks. (See Figure 1-7.) Be sure the INPUTS switch is in the FRONT position. Set the function generator to output a 1kHz, 1V RMS sine wave. Select the Model 2701 frequency function by pressing the FREQ key. Verify that the Model 2701 frequency reading is between 999.9Hz and 1.0001kHz. 2. 3. 4.
Model 2701 Service Manual Performance Verification 1-19 Follow these steps to verify DC voltage accuracy: 1. Connect the Model 7700 CH1 H and L INPUT terminals to the DC voltage calibrator as shown in Figure 1-8. NOTE Use shielded, low-thermal connections when testing the 100mV and 1V ranges to avoid errors caused by noise or thermal effects. Connect the shield to the calibrator’s output LO terminal.
1-20 Performance Verification Model 2701 Service Manual Verifying AC voltage Check AC voltage accuracy by applying accurate AC voltages at specific frequencies from the AC voltage calibrator to the Model 7700 inputs and verifying that the displayed readings fall within specified ranges. CAUTION Do not exceed 300V RMS between plug-in module INPUT H and L terminals or between adjacent channels, or 8 × 107 V•Hz input, because instrument damage may occur.
Model 2701 Service Manual 2. 3. 4. 5. 6. Performance Verification 1-21 Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position. Select the AC volts function by pressing the ACV key. Close Channel 1 by pressing the CLOSE key and then keying in 101. Set the Model 2701 for the 100mV range, make sure that REL is disabled.
1-22 Performance Verification Model 2701 Service Manual Verifying DC current Check DC current accuracy by applying accurate DC currents from the DC current calibrator to the input terminals of the Model 7700 and verifying that the displayed readings fall within specified limits. Follow these steps to verify DC current accuracy: 1. Connect the Model 7700 CH21 H and L terminals to the calibrator as shown in Figure 1-10.
Model 2701 Service Manual 2. 3. 4. 5. 6. Performance Verification 1-23 Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position. Select the DC current measurement function by pressing the DCI key. Set the Model 2701 for the 20mA range. Close Channel 21 by pressing the CLOSE key and keying in 121.
1-24 Performance Verification Model 2701 Service Manual Verifying AC current Check AC current accuracy by applying accurate AC voltage current at specific frequencies from the AC current calibrator to the Model 7700 input terminals and verifying that the displayed readings fall within specified limits. Follow these steps to verify AC current: 1. Connect the Model 7700 CH21 H and L terminals to the calibrator as shown in Figure 1-11.
Model 2701 Service Manual Performance Verification 1-25 Verifying resistance Check resistance by connecting accurate resistance values to the Model 7700 and verifying that its resistance readings are within the specified limits. CAUTION Do not apply more than 300V between plug-in module INPUT or SENSE H and L terminal, or between any adjacent channels, or instrument damage could occur. Follow these steps to verify resistance accuracy: 1.
1-26 Performance Verification 2. 3. 4. 5. 6. 7. Model 2701 Service Manual Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position. Set the calibrator for 4-wire resistance with external sense on. Select the Model 2701 4-wire resistance function by pressing the Ω4 key. Close Channel 1 by pressing the CLOSE key and keying in 101.
Model 2701 Service Manual 8. 9. 10. 11. 12. Performance Verification 1-27 Connect the Model 7700 CH1 and CH11 terminals to the calibrator as shown in Figure 1-13. Disable external sense on the calibrator. Set the Model 2701 for the 100MΩ range. Source a nominal 100MΩ resistance value and verify that the reading is within calculated limits for the 100MΩ range. Press the OPEN key to open Channel 1.
1-28 Performance Verification Model 2701 Service Manual Verifying temperature Thermocouple, thermistor, and RTD temperature readings are derived from DC volts and resistance measurements respectively. For that reason, it is not necessary to independently verify the accuracy of temperature measurements. As long as the DC volts and resistance functions meet or exceed specifications, temperature function accuracy is automatically verified.
Model 2701 Service Manual Performance Verification 1-29 Figure 1-14 Connections for Model 7700 thermocouple temperature verification Twisted Thermocouple Wire CH1 Calibrator (Output DC Voltage) INPUT SENSE CH1 CH2 H L H L H L H L CH3 CH4 CH5 CH6 H L H L H L H L CH7 CH8 CH9 CH10 H L H L H L H L Output HI INPUT (V, 2 WIRE) SENSE (OHMS, 4 WIRE) LO H L H L CH21 CH22 AMPS H L H L H L H L CH17 CH18 CH19 CH20 Output LO H L H L H L H L H L H L CH11 CH12 CH13 CH14 CH15 CH16 Model 7700 Low Thermal C
1-30 Performance Verification Model 2701 Service Manual RTD temperature 1. 2. 3. 4. 5. Connect the precision decade resistance box (listed in Table 1-1) to the Model 7700 CH1 and CH11 H and L terminals using four-wire connections. (See Figure 1-12 for similar connecting scheme.) Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position.
Model 2701 Service Manual Performance Verification 1-31 Verifying frequency Follow the steps below to verify the Model 2701 frequency function: 1. 2. 3. 4. 5. Connect the function generator to the Model 7700 CH1 H and L INPUT terminals. (See Figure 1-15.) Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for one hour before proceeding. Be sure the front panel INPUTS switch is set to the REAR position.
1-32 Performance Verification Model 2701 Service Manual Verifying ratio and average Follow the procedure below to verify ratio and average. CAUTION 1. 2. 3. 4. 5. 6. 7. Exceeding 300V between plug-in module INPUT or SENSE H and L terminals may cause instrument damage. Connect the Model 7700 CH1 and CH11 H and L terminals to the DC calibrator, as shown in Figure 1-16.
2 Calibration
2-2 Calibration Model 2701 Service Manual Introduction Use the procedures in this section to calibrate the Model 2701. Calibration procedures include: • • • Comprehensive calibration: Usually the only calibration required in the field. Manufacturing calibration: Usually only performed at the factory (unless the unit has been repaired). Model 7700 calibration: Covers calibration procedures specific to Model 7700 cards.
Model 2701 Service Manual Calibration 2-3 Calibration considerations When performing the calibration procedures: • • • • Make sure that the equipment is properly warmed up and connected to the appropriate input jacks. Also make sure that the correct front or rear terminals are selected with the INPUTS switch. Make sure the calibrator is in OPERATE before you complete each calibration step. Always let the source signal settle before calibrating each point.
2-4 Calibration Model 2701 Service Manual Calibration code Before performing comprehensive calibration, you must first unlock calibration by entering the appropriate calibration code. Front panel calibration code For front panel calibration, follow these steps: 1. 2. 3. 4. Access the calibration menu by pressing SHIFT then TEST, then use the up or down range key to display TEST: CALIB.
Model 2701 Service Manual Calibration 2-5 Comprehensive calibration The comprehensive calibration procedure calibrates the DCV, DCI, ACV, ACI, and ohms functions. You can also choose to calibrate only the DCV/DCI and resistance or ACV/ACI functions. These procedures are usually the only calibration required in the field. Manufacturing calibration is normally done only at the factory, but it should also be done in the field if the unit has been repaired.
2-6 Calibration Model 2701 Service Manual Aborting calibration You can abort the front panel calibration process at any time by pressing EXIT. The instrument will then ask you to confirm your decision to abort with the following message: ABORT CAL? Press EXIT to abort calibration at this point or press any other key to return to the calibration process. NOTE The Model 2701 will not respond to any remote programming commands while the ABORT CAL? message is displayed.
Model 2701 Service Manual Calibration 2-7 Table 2-2 Comprehensive calibration procedures Procedure Menu choice Procedures Full calibration DCV, DCI, and ohms ACV and ACI ALL DC AC All comprehensive calibration steps (DC and AC) DC voltage, DC current, and resistance calibration AC voltage and AC current calibration Front panel short and open calibration At the Model 2701 prompt for a front panel short, perform the following: 1.
2-8 Calibration Model 2701 Service Manual DC voltage calibration After the front panel short and open procedure, the unit will prompt you for the first DC voltage: +10V. Do the following: 1. Connect the calibrator to the Model 2701 as shown in Figure 2-2. Wait three minutes to allow for thermal equilibrium before proceeding.
Model 2701 Service Manual NOTE Calibration 2-9 If your calibrator cannot output the values recommended in Table 2-3, use the left and right arrow keys and the up and down range keys to set the Model 2701 display value to match the calibrator output voltage. Table 2-3 DC volts calibration summary Calibration step Calibrator voltage Allowable range +10V -10V 100V +10.00000V -10.00000V +100.
2-10 Calibration Model 2701 Service Manual DC current calibration After the 1MΩ resistance point has been calibrated, the unit will prompt you to apply 10mA. Follow these steps for DC current calibration: 1. Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2701 as shown in Figure 2-3.
Model 2701 Service Manual Calibration 2-11 AC voltage calibration Follow these steps for AC voltage calibration: 1. Connect the calibrator to the Model 2701 INPUT HI and LO terminals as shown in Figure 2-4.
2-12 Calibration Model 2701 Service Manual AC current calibration After the 700VAC at 1kHz point has been calibrated, the unit will prompt you for 100mA at 1kHz. Follow these steps for AC current calibration: 1. 2. Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2701 as shown in Figure 2-3. Perform the calibration steps summarized in Table 2-7. For each step: • Set the calibrator to the indicated current and frequency, make sure the unit is in OPERATE.
Model 2701 Service Manual Calibration 2-13 Remote calibration Follow the steps in this section to perform comprehensive procedures via remote. See Appendix B for a detailed list and description of remote calibration commands. When sending calibration commands, be sure that the Model 2701 completes each step before sending the next command. You can do so either by observing the front panel CALIBRATING message or by detecting the completion of each step via remote.
2-14 Calibration Model 2701 Service Manual Short and open calibration 1. NOTE 2. 3. NOTE Connect the Model 8610 low-thermal short to the instrument INPUT and SENSE terminals as shown in Figure 2-1. Make sure the INPUTS button is not pressed in so that the front inputs are active. Wait at least three minutes before proceeding to allow for thermal equilibrium. Be sure to connect the low-thermal short properly to the HI, LO, and SENSE terminals.
Model 2701 Service Manual NOTE Calibration 2-15 Ensure the calibrator has settled to the final value. You can do so by verifying that the “Settled” indicator is off or by using the *OPC? (operation complete) query. Table 2-8 DC voltage calibration programming steps Calibration step Calibrator voltage Calibration command* Parameter range +10V -10V 100V +10.00000V -10.00000V 100.
2-16 Calibration Model 2701 Service Manual DC current calibration After the 1MΩ resistance point has been calibrated, follow these steps for DC current calibration: 1. 2. Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2701 as shown in Figure 2-3. Perform the calibration steps listed in Table 2-10. For each step: • Set the calibrator to the indicated current and make sure the unit is in operate. (Use the recommended current if possible.) • Send the indicated programming command.
Model 2701 Service Manual Calibration 2-17 AC voltage calibration Follow these steps for AC voltage calibration: 1. 2. Connect the calibrator to the Model 2701 INPUT HI and LO terminals as shown in Figure 2-4. Perform the calibration steps summarized in Table 2-11. For each step: • Set the calibrator to the indicated voltage and frequency, make sure the unit is in operate. (You must use the stated voltage and frequency.) • Send the indicated programming command.
2-18 Calibration Model 2701 Service Manual AC current calibration Follow these steps for AC current calibration: 1. 2. Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2701 as shown in Figure 2-3. Perform the calibration steps summarized in Table 2-12. For each step: • Set the calibrator to the indicated current and frequency, make sure the unit is in operate. (You must use the stated current and frequency.) • Send the indicated programming command.
Model 2701 Service Manual Calibration 2-19 Manufacturing calibration The manufacturing calibration procedure is normally performed only at the factory, but the necessary steps are included here in case the unit is repaired and the unit requires these calibration procedures. NOTE If the unit has been repaired, the entire comprehensive calibration procedure should also be performed in addition to the manufacturing calibration procedure.
2-20 Calibration Model 2701 Service Manual Measuring function generator signal amplitude The 3Hz function generator signal amplitude must be accurately measured using the digital multimeter listed in Table 2-13. Proceed as follows: 1. 2. 3. Connect the function generator output to the digital multimeter INPUT jacks. (See Figure 2-5 for typical connections.) Turn on the function generator and multimeter, allow a two-hour warm-up period before measuring.
Model 2701 Service Manual 8. 9. Calibration 2-21 After the last AC current calibration step, the instrument will prompt you to enter 3Hz at 1V RMS and 1kHz with the following prompts: • Low-frequency cal — Set the function generator to output a 1V RMS, 3Hz sine wave. Use the left and right arrow keys and the range keys to adjust the display to agree with the generator amplitude you measured previously, then press ENTER. • Frequency cal — Set the function generator to output a 1V RMS, 1kHz sine wave.
2-22 Calibration Model 2701 Service Manual Model 7700 calibration The following procedures calibrate the temperature sensors on the Model 7700 plug-in modules. NOTE For additional information about the Keithley modules, refer to the appropriate appendix in the Model 2701 User’s Manual. Recommended test equipment In order to calibrate the Model 7700, you will need equipment summarized in Table 2-14. Table 2-14 Recommended equipment for Model 7700 calibration Digital Thermometer: 18° to 28°C, ±0.
Model 2701 Service Manual 5. 6. 7. Calibration 2-23 Press SHIFT then TEST, then display TEST:CALIB with the up or down range key. Press ENTER, select RUN, then enter the appropriate calibration code (default: 002701). Using the up or down range key, select CARD at the CAL:RUN prompt, then press ENTER. Set the display value to the cold calibration temperature (°C) you measured in Step 3, then press ENTER to complete Model 7700 calibration. Remote Model 7700 calibration 1. 2. 3. 4. 5. 6. 7. 8.
3 Routine Maintenance
3-2 Routine Maintenance Model 2701 Service Manual Introduction The information in this section deals with routine type maintenance and includes procedures for setting the line voltage, replacing the Model 2701 line and front terminal AMPS fuses, and replacing the amps fuses for the Model 7700 plug-in module. Replacement of the Model 2701 non-volatile RAM battery and module relay closure count is also covered.
Model 2701 Service Manual Routine Maintenance Figure 3-1 Power module Model 2701 WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY. 10bT DIGITAL I/O (EXT. TRIG.) TRIG. LINK 100bT CAT I MADE IN U.S.A. ETHERNET ! 10/100 BaseT RS232 ! SLT 1 KEITHLEY SLOT COVER SLT 2 Line Voltage Selector CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.
3-4 Routine Maintenance Model 2701 Service Manual Replacing the front terminal AMPS fuse The front terminal AMPS fuse protects the Model 2701 current input from an over-current condition. Follow the steps below to replace the AMPS fuse. WARNING 1. 2. 3. Make sure the instrument is disconnected from the power line and other equipment before replacing the AMPS fuse. Turn off the power and disconnect the power line and test leads.
Model 2701 Service Manual Routine Maintenance 3-5 Replacing Model 7700 plug-in module amps fuses WARNING The information in this section is intended only for qualified service personnel. Do not perform these procedures unless you are qualified to do so. Make sure that all plug-in module connections are de-energized and disconnected before replacing module amps fuses. 1. Turn off the power and disconnect the power line and external connections from the Model 7700. Open the Model 7700 top cover.
3-6 Routine Maintenance 8. 9. Model 2701 Service Manual Carefully clean the repaired area of the circuit board with a foam tipped swab or brush dipped in pure water, then blow dry the board with dry nitrogen gas. Allow the board to dry for several hours in a 50°C low-humidity environment before use. Re-install the circuit board into the plastic housing, then close the top cover. Replacing non-volatile RAM battery The Model 2701 has a rechargeable lithium ion battery for non-volatile RAM.
Model 2701 Service Manual Routine Maintenance 3-7 Plug-in module relay closure count The Model 2701 keeps an internal count of the number of times each module relay has been closed. This count will help you determine if and when any relays require replacement (see module contact life specifications). The count can be read or reset only via remote as outlined below. Closure count commands Table 3-2 summarizes closure count commands.
3-8 Routine Maintenance Model 2701 Service Manual Resetting relay closure count NOTE The Model 2701 must be in the manufacturing calibration mode to reset the closure count. To do so, press and hold the OPEN key while turning on the power, then send the :CAL:PROT:CODE “code” to unlock calibration (default code: KI002701). After resetting relay counts, send :CAL:PROT:LOCK to lock out calibration.
4 Troubleshooting
4-2 Troubleshooting Model 2701 Service Manual Introduction This section of the manual will assist you in troubleshooting and repairing the Model 2701. Included are self-tests, test procedures, troubleshooting tables, and circuit descriptions. It is left to the discretion of the repair technician to select the appropriate tests and documentation needed to troubleshoot the instrument. Refer to the disassembly procedures in Section 5 and the parts lists in Section 6 for further information.
Model 2701 Service Manual Troubleshooting 4-3 Power-on self-tests RAM and EPROM tests During the power-on sequence, the Model 2701 will perform a checksum test on its EPROM and test its RAM. If the RAM tests fails, the instrument will lock up. Flash memory tests After the RAM and EPROM tests, the instrument will perform a checksum test on flash memory. If a failure occurs, the unit will perform the comprehensive tests summarized in Table 4-1.
4-4 Troubleshooting Model 2701 Service Manual Front panel tests There are two front panel tests: one to test the functionality of the front panel keys and one to test the display. In the event of a test failure, refer to “Display board checks” on page 4-13 for details on troubleshooting the display board. KEY test The KEY test allows you to check the functionality of each front panel key. Perform the following steps to run the KEY test: 1. 2. 3. 4.
Model 2701 Service Manual Troubleshooting 4-5 Principles of operation The following information is provided to support the troubleshooting tests and procedures covered in this section of the manual.
4-6 Troubleshooting Model 2701 Service Manual AC power is applied to the AC power module receptacle. Power is routed through the line fuse and line voltage selection switch of the power module to the power transformer. The power transformer has a total of four secondary windings for the various supplies. AC voltage for the display filaments is taken from a power transformer secondary at F1 and F2, then routed to the display board.
Model 2701 Service Manual Troubleshooting 4-7 Figure 4-2 Digital circuitry block diagram Li Ion Battery Battery Control/ Charger U4, U16 XADTX Analog Circuitry XADCLK XADTS (See Figure 4-3) XADRX U13 U21 U22 Slot Control Real Time Clock Flash Memory U7 U6 SDRAM U3 Keypad O P T O ADTX ADCLK I S O ADTS U150 U155 U175 Main Processor MCF5407 Display Board Controller U401 U1 Display DS401 ADRXB 50 MHz XTAL Y1 RX RS-232 U15 RS-232 Port TX FPGA Digital I/O U9 U23, U24 IN OUT SDRAM
4-8 Troubleshooting Model 2701 Service Manual Display DS401 is the display module, which can display up to 12 alpha-numeric characters and includes the various annunciators. The display uses a common multiplexing scheme with each character refreshed in sequence. U402 and U403 are the drivers for the display characters and annunciators. Note that data for the drivers are serially transmitted from the microcontroller (MOSI and PC1).
Model 2701 Service Manual Troubleshooting 4-9 RS-232 interface Serial data transmission and reception is performed by the TXD and RXD lines of the MPU. U15 provides the necessary voltage level conversion for the RS-232 interface port. Trigger circuits Buffering for Trigger Link input and output is performed by U14 and U20. Trigger input and output is controlled by FPGA U9 under MPU supervision. Digital I/O U23 and U24 make up the digital input/output.
4-10 Troubleshooting Model 2701 Service Manual Analog circuitry Refer to Figure 4-3 for the following discussion on analog circuitry. INPUT HI INPUT HI protection is provided by the SSP (Solid State Protection) circuit. The SSP is primarily made up of Q101 and Q102. An overload condition opens Q101 and Q102, which disconnects the analog input signal from the rest of the analog circuit. Note that for the 100VDC and 1000VDC ranges, Q101 and Q102 of the SSP are open.
Model 2701 Service Manual Troubleshooting 4-11 Figure 4-3 Analog circuitry block diagram Front Terminals S101 Scanner Outputs AMPS Current Shunts K103, R158, R205, R338 DCA ACA AC Switching & Gain K102, U102, U103, U105, U112, U118, U111, U110 Front Terminals S101 K101 Scanner Outputs ACV, FREQ DCV OHMS SSP* Q101, Q102 INPUT HI DCV DCV/100 Divider R117, Q109, Q114, Q136 DCV & Ohms Switching Q104, Q105 Q108, Q113 X1 Buffer U113 BUFCOM A/D MUX & Gain U129, U132 U163, U166 ADC U165 Q120, CR114
4-12 Troubleshooting Model 2701 Service Manual Ohms open-lead sense detection There are two types of open sense lead detect (Figure 4-4). The first is for the INPUT HI and INPUT LO leads. For these leads, the open sense detection is implemented in hardware. A comparator circuit monitors the voltage at the INPUT HI lead output and will trip the OVLD detect circuit when the voltage level exceeds an appropriate value for the particular range.
Model 2701 Service Manual Troubleshooting 4-13 Troubleshooting Troubleshooting information for the various circuits is summarized below. See “Principles of operation” on page 4-5 for circuit theory. Display board checks If the front panel DISP tests show a failure, troubleshoot the display board using Table 4-3.
4-14 Troubleshooting Model 2701 Service Manual Digital circuitry checks Digital circuit problems can be checked using Table 4-5. Table 4-5 Digital circuitry checks Step Item/component 1 2 3 4 5 6 7 8 9 10 11 12 Power-on test J1, pin 3 J1, pin 9 U4, pin 9 J900, pin 1 U1, pin 149 U1, lines A0-A24 U1, lines D0-D31 U1, pin 174 U15, pin 13 U15, pin 14 TP8 Required condition Remarks RAM OK, ROM OK. Digital common. +3.3V (+3.3VD supply) +4.2V +4.2V Low on power-up, then goes high. Check for stuck bits.
Model 2701 Service Manual Troubleshooting 4-15 Table 4-7 ACV and FREQ signal switching Range Q101 Q102 K101* K102* U103 pin 8 U103 pin 9 U105 pin 9 U105 pin 8 U103 U103 pin 16 pin 1 100mV 1V 10V 100V 750V ON ON ON ON ON RESET RESET RESET RESET RESET RESET RESET SET SET SET ON ON OFF OFF OFF ON ON OFF OFF OFF OFF OFF ON ON ON OFF OFF OFF OFF ON OFF ON OFF ON OFF ON ON ON ON ON * K101 and K102 reset states: K101 and K102 set states: ON OFF ON OFF OFF U105 pin 1 U111 pin 16 ON OFF ON
4-16 Troubleshooting Model 2701 Service Manual Table 4-9 Ω4 signal switching Range Q101 Q102 Q114 Q136 Q109 K101* Q113 100Ω 1kΩ 10kΩ 100kΩ 1MΩ 10MΩ 100MΩ ON ON ON ON ON ON ON ON ON ON ON ON ON ON OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF ON ON SET SET SET SET SET SET SET * K101 set states: ON ON ON ON ON OFF OFF Q105 Q104 Q108 Q11 OFF OFF OFF OFF OFF ON ON OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF ON ON ON OFF OFF ON ON Pin 8 switche
Model 2701 Service Manual Troubleshooting 4-17 Table 4-12 ACA signal switching Range K103* U105 pin 16 U105 pin 1 U111 pin 16 U105 pin 8 U103 pin 16 U103 pin 1 1A 3A Reset Reset ON ON ON ON OFF ON OFF OFF OFF OFF OFF OFF * K103 set states: Pin 8 to 7 Pin 3 to 4 K103 reset states: Pin 8 to 9 Pin 3 to 2 Table 4-13 through Table 4-17 can be used to trace the analog signal through the A/D multiplexer (U163) to the final amplifier stage.
4-18 Troubleshooting Model 2701 Service Manual Table 4-15 DCA signal multiplexing and gain Range Signal (U163) U129 pin 1 U129 pin 8 U129 pin 9 Gain (U166) 20mA 100mA 1A 3A S6 S6 S6 S6 OFF OFF OFF OFF OFF OFF OFF ON ON ON ON OFF ×100 ×100 ×100 ×10 Table 4-16 Ω2 signal multiplexing and gain Range Signal (U163) U129 pin 1 U129 pin 8 U129 pin 9 Gain (U166) 100Ω 1kΩ 10kΩ 100kΩ 1MΩ 10MΩ 100MΩ S4 S4 S4 S4 S4 S4 S4 OFF OFF OFF OFF ON ON ON OFF ON ON ON OFF OFF OFF ON OFF OFF OFF OFF OFF O
Model 2701 Service Manual Troubleshooting 4-19 Figure 4-3 provides a block diagram of the analog circuitry. Table 4-18 shows where the various switching devices are located in the block diagram.
5 Disassembly
5-2 Disassembly Model 2701 Service Manual Introduction This section explains how to handle, clean, and disassemble the Model 2701 Ethernet Multimeter/Data Acquisition System. Disassembly drawings are located at the end of this section. Handling and cleaning To avoid contaminating PC board traces with body oil or other foreign matter, avoid touching the PC board traces while you are repairing the instrument.
Model 2701 Service Manual Disassembly 5-3 Static sensitive devices CMOS devices operate at very high impedance levels. Therefore, any static that builds up on you or your clothing may be sufficient to destroy these devices if they are not handled properly. Use the following precautions to avoid damaging them: CAUTION • • • • • • • Many CMOS devices are installed in the Model 2701. Handle all semiconductor devices as being static sensitive.
5-4 Disassembly Model 2701 Service Manual Disassembly procedures Case cover removal Follow the steps below to remove the case cover to gain access to internal parts. WARNING 1. 2. NOTE 3. 4. 5. Before removing the case cover, disconnect the line cord and any test leads from the instrument. Remove Handle — The handle serves as an adjustable tilt-bail. Adjust its position by gently pulling it away from the sides of the instrument case and swinging it up or down.
Model 2701 Service Manual 4. 5. 6. Disassembly 5-5 Remove all the connections except the front AMPS connection by pulling the wires off the pin connectors. To remove the front panel AMPS input wire (white), first remove the AMPS fuse holder, then use needle-nose pliers to grasp the AMPS wire near the fuse housing. Push the wire forward and down to snap the spring out of the fuse housing. Carefully pull the spring and contact tip out of the housing.
5-6 Disassembly 3. 4. Model 2701 Service Manual Using a thin-bladed screwdriver, pry the plastic PC board stop (located at the bottom of the display board) until the bar separates from the casing. Pull the display board from the front panel. Remove the switch pad by pulling it from the front panel. Removing power components The following procedures to remove the power transformer, power module, and fan require that the case cover and motherboard be removed, as previously explained.
Model 2701 Service Manual Disassembly 5-7 Instrument reassembly Reassemble the instrument by reversing the previous disassembly procedures. Make sure that all parts are properly seated and secured, and that all connections are properly made. To ensure proper operation, replace and securely fasten the shield.
6 Replaceable Parts
6-2 Replaceable Parts Model 2701 Service Manual Introduction This section contains replacement parts information and component layout drawings for the Model 2701 and Model 7700. Parts lists Both electrical and mechanical parts for the Model 2701 are listed in Table 6-1 through Table 6-4 on the following pages. Parts for the Model 7700 plug-in module are listed in Table 6-5. For additional information on mechanical parts, see the assembly drawings provided at the end of Section 5.
Model 2701 Service Manual Replaceable Parts 6-3 Table 6-1 Model 2701 motherboard parts list Circuit designation Description Keithley part no.
6-4 Replaceable Parts Model 2701 Service Manual Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no.
Model 2701 Service Manual Replaceable Parts 6-5 Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no.
6-6 Replaceable Parts Model 2701 Service Manual Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no.
Model 2701 Service Manual Replaceable Parts 6-7 Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no. R215,R216 R221,R222 R223 R225 R226 R228,R237,R252 R23 R230 R232,R233,R236 R234 R235,R245,R250,R255 R239,R242 R24 R240 R241 R243 R246 R247 R248,R251 R249 R259,R320 R273,R274,R307,R314 R277 R278,R281 R279,R289,296,R299,R305,R319,R342,R390 R287,R316,R317,R349 R290 R302,R303,R383 R304 R308 R309 R310 R311 R312,R313 R315 R318 R323 R341 R350 RES, 4.
6-8 Replaceable Parts Model 2701 Service Manual Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no.
Model 2701 Service Manual Replaceable Parts 6-9 Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no. U112 U113,U126 U114,U167 U115 U116 U117,U145 U119 U12 U120,U131,U169,U186,U30 U123 U124 U125 U13 U132,U138,U139,U190 U133 U137,U166 U14,U20,U29 U141 U142 U144 U148,U153 U149 U15 U150 U154 IC, LOW COST HIGH SPEED JFET AMP IC, OP-AMP, LTC1050CS8 IC, DUAL J-FET OP-AMP, OP-282GS, IC, QUAD COMPARATOR, LM339D IC, DARLINGTON ARRAY, ULN2003L IC, VOLT.
6-10 Replaceable Parts Model 2701 Service Manual Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no. U25 U27 U3,U11 U35 U4 U427 U5 U6 U7 U8 U805-U807 U9 VR102 VR103,VR104 VR105,VR106,VR124,VR125 VR107,VR108,VR110,VR122,VR123 VR109 VR112,VR113 VR119,VR120 Y1 Y102 Y2 IC, 2.5V, 1.
Model 2701 Service Manual Replaceable Parts 6-11 Table 6-2 Model 2701 display board parts list Circuit designation Description Keithley part no. C401,C402,C411,C403,C404,C405,C407,C409 C406,C408 C410,C412 C413 C414 CR401,CR402 DS401 P1014 R401-R404,R406,R409,R411,R414-R418 R405,R408,R410,R412 R413 R419 R420,R421 U401 U402,U403 Y401 CAP, .1UF, 20%, 50V, CERAMIC CAP, 33PF, 10%, 100V, CERAMIC CAP, .1UF, 20%, 50V, CERAMIC CAP, 22UF, 20%, 6.
6-12 Replaceable Parts Model 2701 Service Manual Table 6-4 Model 2701 miscellaneous parts list Quantity 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 2 2 2 2 1 1 1 1 1 1 1 Description Keithley part no. SLOT COVER HANDLE FAN SWITCHPAD CHASSIS REAR PANEL FRONT PANEL FRONT PANEL DISPLAY LENS SLOT COVER BEZEL, REAR FOOT MOUNTING EAR, RIGHT MOUNTING EAR, LEFT POWER ROD BATTERY, LITHIUM ION BANANA JACK, PUSH-IN BLACK BANANA JACK, PUSH-IN RED FOOT, EXTRUDED FOOT, RUBBER FUSE HOLDER FUSE, .
Model 2701 Service Manual Replaceable Parts 6-13 Table 6-5 Model 7700 parts list Circuit designation Description Keithley part no.
6-14 Replaceable Parts Model 2701 Service Manual Table 6-5 (Continued) Model 7700 parts list Circuit designation Description Keithley part no. U16 U24 U6 U7,U25 U9,U10 IC, 2.
A Specifications
PURCHASED ITEM 2701 Ethernet Multimeter/Data Acquisition System DC CHARACTERISTICS1 CONDITIONS: MED (1 PLC)2 or 10 PLC or MED (1 PLC) with Digital Filter of 10 FUNCTION RANGE RESOLUTION Voltage 11 100.0000 mV 1.000000 V 10.00000 V 100.0000 V 1000.000 V 5 0.1 1.0 10 100 1 µV µV µV µV mV Resistance 6, 8 100.0000 Ω 1.000000 kΩ 10.00000 kΩ 100.0000 kΩ 1.000000 MΩ 10.00000 MΩ 7 100.0000 MΩ 7 100 1 10 100 1.0 10 100 µΩ mΩ mΩ mΩ Ω Ω Ω 100 10 100 1.0 10 mΩ nA nA µA µA Continuity (2W)21 1.
PURCHASED ITEM 2701 Ethernet Multimeter/Data Acquisition System DC Notes DC SPEED vs. NOISE REJECTION Rate Filter Readings/s12 10 50 0.1 (0.08) 1 Off 15 (12) 0.1 Off 500 (400) 0.006 Off 3000 (3000) 0.002 Off 3500 (3500) RMS Noise Digits 10V Range NMRR 6.5 < 2.5 µV 110 dB13 6.5 < 6 µV 90 dB13 5.5 < 40 µV — 4.5 < 300 µV — 3.5 < 1mV — CMRR 14 140 dB 140 dB 80 dB 80 dB 60dB DC MEASUREMENT CHARACTERISTICS 1. 20% overrange except on 1000V and 3A. 2.
PURCHASED ITEM 2701 Ethernet Multimeter/Data Acquisition System Additional Uncertainty ±(% of reading) Low Frequency Uncertainty 20 Hz - 30 Hz 30 Hz - 50 Hz 50 Hz - 100 Hz 100 Hz - 200 Hz 200 Hz - 300 Hz >300 Hz MED 0.3 0 0 0 0 0 1 -2 2 - 3 CREST FACTOR: 5 Additional Uncertainty: 0.05 0.15 Maximum Crest Factor: 5 at full-scale. AC Notes FAST — — 1.0 0.18 0.10 0 3-4 0.30 4-5 0.40 AC MEASUREMENT CHARACTERISTICS AC Volts MEASUREMENT METHOD: AC-coupled, True RMS. INPUT IMPEDANCE: 1MΩ ±2% // by <100pF.
7700 20-Channel Differential Multiplexer w/Automatic CJC GENERAL 20 CHANNELS: 20 channels of 2-pole relay input. All channels configurable to 4-pole. 2 CHANNELS: 2 channels of current only input. RELAY TYPE: Latching electromechanical. ACTUATION TIME: <3ms. HI Card Input LO HI Card Sense LO Cold junction Ref x3 HI CAPABILITIES Channel 1 CHANNELS 1-20: Multiplex one of 20 2-pole or one of 10 4-pole signals into DMM. CHANNELS 21-22: Multiplex one of 2 2-pole current signals into DMM.
A-6 Specifications Model 2701 Service Manual Accuracy calculations The information below discusses how to calculate accuracy for both DC and AC characteristics. Calculating DC characteristics accuracy DC characteristics accuracy is calculated as follows: Accuracy = ±(ppm of reading + ppm of range) (ppm = parts per million and 10ppm = 0.001%) As an example of how to calculate the actual reading limits, assume that you are measuring 5V on the 10V range.
Model 2701 Service Manual Specifications A-7 Calculating dBm characteristics accuracy As an example of how to calculate the actual reading limits for a 13dBm measurement with a reference impedance of 50Ω, assume an applied signal 0.998815V. The relationship between voltage and dBm is as follows: 2 VIN ⁄ R REF dBm = 10 log --------------------------1mW From the previous example on calculating DC characteristics accuracy, it can be shown that a measurement of 0.
A-8 Specifications Model 2701 Service Manual Calculating dB characteristics accuracy The relationship between voltage and dB is as follows: V IN dB = 20 log ----------V REF As an example of how to calculate the actual readings limits for dB, with a user-defined VREF of 10V, you must calculate the voltage accuracy and apply it to the above equation. To calculate a -60dB measurement, assume 10mV RMS for a VREF of 10V.
Model 2701 Service Manual Specifications A-9 Optimizing measurement accuracy The configurations listed below assume that the multimeter has had factory setups restored. DC voltage, DC current, and resistance: • • • Select 6½ digits, 10 PLC, filter ON (up to 100 readings), fixed range. Use REL on DC voltage and 2-wire resistance measurements. Use 4-wire resistance measurements for best accuracy. AC voltage and AC current: • Select 6½ digits, 10 PLC, filter ON (up to 100 readings), fixed range.
B Calibration Reference
B-2 Calibration Reference Model 2701 Service Manual Introduction This appendix contains detailed information about the various Model 2701 remote calibration commands. Section 2 of this manual covers detailed calibration procedures. For information about additional commands to control other instrument functions, refer to the Model 2701 User’s Manual. Command summary Table B-1 summarizes Model 2701 calibration commands.
Model 2701 Service Manual Calibration Reference B-3 Table B-1 (Continued) Remote calibration command summary Command Description :CALibration :PROTected :DC :STEP9 :STEP10 :STEP11 :STEP12 :AC :STEP1 :STEP2 :STEP3 :STEP4 :STEP5 :STEP6 :STEP7 :STEP8 :STEP9 :STEP10 :STEP11 :STEP12 :STEP13 :STEP14 :STEP15 1MΩ 4-wire step. 10mA DC step. 100mA DC step. 1A DC step. AC cal steps. 10mV AC at 1kHz step. 100mV AC at 1kHz step. 100mV AC at 50kHz step. 1V AC at 1kHz step.
B-4 Calibration Reference Model 2701 Service Manual Miscellaneous calibration commands Miscellaneous commands perform miscellaneous calibration functions such as programming the calibration code and date. These commands are discussed in detail in the following paragraphs. :CODE (:CALibration:PROTected:CODE) Purpose To program the calibration code or password so that you can perform the calibration procedures.
Model 2701 Service Manual Calibration Reference B-5 :INIT (:CALibration:PROTected:INITiate) Purpose To initiate comprehensive and factory calibration procedures. Format :cal:prot:init Parameter None Description The :INIT command enables Model 2701 calibration when performing these procedures over the bus. This command must be sent to the unit after sending the :CODE command, but before sending any other calibration command.
B-6 Calibration Reference Model 2701 Service Manual :LOCK? (:CALibration:PROTected:LOCK?) Purpose To read comprehensive calibration lock status. Format :cal:prot:lock? Response 0 1 Description The :LOCK? query requests status from the Model 2701 on calibration locked/unlocked state. Calibration must be enabled sending the :CODE command before calibration can be performed. Example :CAL:PROT:LOCK? Comprehensive calibration locked. Comprehensive calibration unlocked. Request cal lock state.
Model 2701 Service Manual Calibration Reference B-7 :DATE (:CALibration:PROTected:DATE) Purpose To send the calibration date to the instrument. Format :cal:prot:date , , Parameter = 1999 to 2098 = 1 to 12 = 1 to 31 Query format :cal:prot:date? Response , , Description The :DATE command allows you to store the calibration date in instrument memory for future reference.
B-8 Calibration Reference Model 2701 Service Manual :DATA? (:CALibration:PROTected:DATA?) Purpose To read calibration constants data. Format :cal:prot:data? Response Floating-point, ASCII values separated by commas. Description The :DATA? query requests all the calibration constants. Values are returned in one string of ASCII floating-point values delimited by commands. Example :CAL:PROT:DATA? Request cal constants.
Model 2701 Service Manual Calibration Reference B-9 DC calibration commands The :DC commands perform calibration of the DCV, DCI, and ohms functions. Table B-2 summarizes these calibration commands along with parameter limits. Table B-2 DC calibration commands Command Description Parameter limits :CALibration :PROTected :DC :STEP1 :STEP2 :STEP3 :STEP4 :STEP5 :STEP6 :STEP7 :STEP8 :STEP9 :STEP10 :STEP11 :STEP12 Front terminal short circuit.
B-10 Calibration Reference Model 2701 Service Manual :STEP2 (:CALibration:PROTected:DC:STEP2) Purpose To perform front terminal open-circuit calibration. Format :cal:prot:dc:step2 Parameter None Description :STEP2 performs the open-circuit calibration step in the comprehensive calibration procedure. Disconnect all cables and accessories from the input jacks before sending this command. Example :CAL:PROT:DC:STEP2 Perform open circuit calibration.
Model 2701 Service Manual Calibration Reference B-11 :STEP5 (:CALibration:PROTected:DC:STEP5) Purpose To program the 100V DC comprehensive calibration step. Format :cal:prot:dc:step5 Parameter = 90 to 110 [V] Description :STEP5 programs the 100V DC comprehensive calibration step. The allowable range of the calibration voltage parameter is from 90 to 110, but 100 is recommended for best results. Example :CAL:PROT:DC:STEP5 100 Program 100V step.
B-12 Calibration Reference Model 2701 Service Manual :STEP8 (:CALibration:PROTected:DC:STEP8) Purpose To program the 100kΩ 4-wire comprehensive calibration step. Format :cal:prot:dc:step8 Parameter = 90E3 to 110E3 [Ω] Description :STEP8 programs the 100kΩ 4-wire resistance comprehensive calibration step. The allowable range of the calibration resistance parameter is from 90E3 to 110E3, but 100E3 is recommended for best results.
Model 2701 Service Manual Calibration Reference B-13 :STEP11 (CALibration:PROTected:DC:STEP11) Purpose To program the 100mA comprehensive calibration step. Format :cal:prot:dc:step11 Parameter = 90E-3 to 110E-3 [A] Description :STEP11 programs the 100mA comprehensive calibration step. The allowable range of the calibration current parameter is from 90E-3 to 110E-3. Use the 100E-3 value whenever possible for best results.
B-14 Calibration Reference Model 2701 Service Manual AC calibration commands The :AC commands perform comprehensive (user) calibration of the ACV and ACI functions. Table B-3 summarizes these calibration commands. Table B-3 AC calibration commands Command Description :CALibration :PROTected :AC :STEP1 :STEP2 :STEP3 :STEP4 :STEP5 :STEP6 :STEP7 :STEP8 :STEP9 :STEP10 :STEP11 :STEP12 :STEP13 10mV AC at 1kHz calibration step. 100mV AC at 1kHz calibration step. 100mV AC at 50kHz calibration step.
Model 2701 Service Manual Calibration Reference B-15 :AC:STEP (CALibration:PROTected:AC:STEP) Purpose To program individual AC calibration steps. Format :cal:prot:ac:step Parameter 1 2 3 4 5 6 7 8 9 10 11 12 13 Description The :AC:STEP command programs the 13 individual AC calibration steps; represents the calibration step number. The appropriate signal must be connected to the instrument when programming each step, as summarized in the parameters listed above.
B-16 Calibration Reference Model 2701 Service Manual Manufacturing calibration commands Three calibration steps are only performed at the factory or when the unit has been repaired: 1V AC at 3Hz 1V AC at 1kHz Rear scanner terminal short circuit :CALibration:PROTected:AC:STEP14 :CALibration:PROTected:AC:STEP15 :CALibration:PROTected:DC:STEP0 :AC:STEP<14|15> (CALibration:PROTected:AC:STEP<14|15>) Purpose To program individual AC manufacturing calibration steps.
Model 2701 Service Manual Calibration Reference B-17 Model 7700 calibration commands Table B-4 summarizes calibration commands for the Model 7700 plug-in module. Note that CARD1 commands calibrate the card in Slot 1, while CARD2 commands request calibration count and date information from a card in Slot 2. NOTE A Model 7700 must be installed in Slot 1 through a Model 7797 Calibration System card to be calibrated. See “Model 7700 calibration” in Section 2.
B-18 Calibration Reference Model 2701 Service Manual :CODE (:CALibration:PROTected:CODE) Purpose To program the calibration code or password so that you can perform the Model 7700 calibration procedures. Format :cal:prot:code '' Parameter Up to a 8-character string including letters and numbers. Description The :CODE command enables the Model 2701 calibration procedures when performing these procedures over the bus.
Model 2701 Service Manual Calibration Reference B-19 :DATE? (:CALibration:PROTected:CARD1:DATE?) (:CALibration:PROTected:CARD2:DATE?) Purpose To request the Model 7700 calibration date. Format :cal:prot:card1:date? :cal:prot:card2:date? Response , , Description The :CARD1:DATE? and :CARD2:DATE? queries allow you to read back the calibration date from a Model 7700 in Slot 1 and Slot 2, respectively.
B-20 Calibration Reference Model 2701 Service Manual :LOCK (:CALibration:PROTected:CARD1:LOCK) Purpose To lock out Model 7700 calibration. Format :cal:prot:card1:lock Parameter None Description The :LOCK command allows you to lock out Model 7700 calibration after completing the procedure. Thus, :LOCK performs the opposite of enabling calibration with the :CODE command. Example :CAL:PROT:CARD1:LOCK Lock out card 1 calibration.
Model 2701 Service Manual Calibration Reference B-21 :SAVE (:CALibration:PROTected:CARD1:SAVE) Purpose To save calibration constants in card EEROM after the calibration procedure. Format :cal:prot:card1:save Parameter None Description The :SAVE command stores calculated calibration constants derived during Model 7700 calibration in card EEROM. (EEROM is non-volatile memory.) Calibration constants will be retained indefinitely once saved.
B-22 Calibration Reference Model 2701 Service Manual Remote error reporting Methods to detect and determine the nature of calibration errors are discussed in the following paragraphs. See the Model 2701 User’s Manual for details on status register operation. Error summary Table B-5 summarizes Model 2701 calibration errors.
Model 2701 Service Manual Table B-5 (Continued) Calibration error summary Error number and description +451, +452, +453, +454, +455, +456, +457, +458, +459, +460, +461, +462, +463, +464, +465, +466, +467, +468, +469, +470, +471, +472, +473, +474, +475, +476, +500, +513, +514, +515, +518, +519, +610, "1 vac dac error" "10 vac dac error" "100 vac dac error" "100m vac zero error" "100m vac full scale error" "1 vac zero error" "1 vac full scale error" "1 vac noise error" "10 vac zero error" "10 vac full scale
B-24 Calibration Reference Model 2701 Service Manual Error queue As with other Model 2701 errors, any calibration error will be reported in the remote error queue. You can read this queue by using the :SYST:ERR? query. The Model 2701 will respond with the appropriate error message, as summarized in Table B-5. Status byte EAV (Error Available) bit Whenever an error is available in the error queue, the EAV (Error Available) bit (bit 2) of the status byte will be set.
Index C :AC:STEP B-15, B-16 :CODE B-4, B-18 :COUNt? B-4, B-18 :DATE B-7 :DATE? B-19 :DC:STEP0 B-16 :INIT B-5, B-19 :LOCK B-5, B-20 :LOCK? B-6, B-8, B-20 :NDUE B-7 :RCOunt B-20 :SAVE B-6, B-21 :STEP0 B-21 :STEP1 B-9 :STEP10 B-12 :STEP11 B-13 :STEP12 B-13 :STEP2 B-10 :STEP3 B-10 :STEP4 B-10 :STEP5 B-11 :STEP6 B-11 :STEP7 B-11 :STEP8 B-12 :STEP9 B-12 A AC calibration commands B-14 AC characteristics accuracy A-2 AC current A-5 verifying, Model 2700 1-13 AC voltage A-5 verifying, Model 2700 1-10 verifying, Mo
Model 2700 resistance verification (100Ω to 10MΩ ranges) 1-14 Model 7700 AC current verification 1-24 Model 7700 AC volts verification 1-20 Model 7700 DC current verification 1-22 Model 7700 DC volts verification 1-19 Model 7700 frequency verification 1-31 Model 7700 ratio and average verification 1-32 Model 7700 resistance verification (100MΩ range) 1-27 Model 7700 resistance verification (100Ω to 10MΩ ranges) 1-25 Model 7700 thermocouple temperature verification 1-29 Power module wire 5-7 D dB characteri
Power supply checks 4-13 Power supply components 4-6 Power transformer removal 5-6 Power-on self-test 4-3 line fuse replacing 3-2 Line power 1-3, 2-2 line voltage setting 3-2 R M ratio and average verifying, Model 7700 1-32 reading limit ACV, Model 2700 1-11 calculating resistance 1-5 calculation, example 1-5 DCV, Model 2700 1-9 four-wire RTD temperature verification, Model 2700 1-17 Model 7700 thermocouple temperature verification 1-29 Plug-in module ACV, Model 7700 1-21 Plug-in module DCV, Model 7700
verification test procedures 1-6 Verification test requirements 1-3 verifying AC current, Model 7700 1-24 Specifications A-1 Static sensitive devices 5-3 Status byte EAV (Error Available) bit B-24 Switching device locations 4-19 T Temperature A-5 temperature RTD, Model 2700 1-17 RTD, Model 7700 1-30 thermocouple, Model 2700 1-16 thermocouple, Model 7700 1-28 verifying, Model 2700 1-16 verifying, Model 7700 1-28 Trigger circuits 4-9 Troubleshooting 4-1 V verification Model 2700 1-8 Model 7700 1-18 Verific
Specifications are subject to change without notice. All Keithley trademarks and trade names are the property of Keithley Instruments, Inc. All other trademarks and trade names are the property of their respective companies. Keithley Instruments, Inc. 28775 Aurora Road • Cleveland, Ohio 44139 • 440-248-0400 • Fax: 440-248-6168 1-888-KEITHLEY (534-8453) • www.keithley.
