Fluke NetDAQ 2640A User manual

PN 942615
March 1995
© 1995 Fluke Corporation, Inc. All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies.
®
2640A/2645A
NetDAQ Data Acquisition Tools
Service Manual

LIMITED WARRANTY & LIMITATION OF LIABILITY
Each Fluke product is warranted to be free from defects in material and workmanship under
normal use and service. The warranty period is one year and begins on the date of shipment.
Parts, product repairs and services are warranted for 90 days. This warranty extends only to the
original buyer or end-user customer of a Fluke authorized reseller, and does not apply to fuses,
disposable batteries or to any product which, in Fluke’s opinion, has been misused, altered,
neglected or damaged by accident or abnormal conditions of operation or handling. Fluke
warrants that software will operate substantially in accordance with its functional specifications for
90 days and that it has been properly recorded on non-defective media. Fluke does not warrant
that software will be error free or operate without interruption.
Fluke authorized resellers shall extend this warranty on new and unused products to end-user
customers only but have no authority to extend a greater or different warranty on behalf of Fluke.
Warranty support is available if product is purchased through a Fluke authorized sales outlet or
Buyer has paid the applicable international price. Fluke reserves the right to invoice Buyer for
importation costs of repair/replacement parts when product purchased in one country is submitted
for repair in another country.
Fluke’s warranty obligation is limited, at Fluke’s option, to refund of the purchase price, free of
charge repair, or replacement of a defective product which is returned to a Fluke authorized
service center within the warranty period.
To obtain warranty service, contact your nearest Fluke authorized service center or send the
product, with a description of the difficulty, postage and insurance prepaid (FOB Destination), to
the nearest Fluke authorized service center. Fluke assumes no risk for damage in transit.
Following warranty repair, the product will be returned to Buyer, transportation prepaid (FOB
Destination). If Fluke determines that the failure was caused by misuse, alteration, accident or
abnormal condition of operation or handling, Fluke will provide an estimate of repair costs and
obtain authorization before commencing the work. Following repair, the product will be returned to
the Buyer transportation prepaid and the Buyer will be billed for the repair and return
transportation charges (FOB Shipping Point).
THIS WARRANTY IS BUYER’S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL
OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY
IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
FLUKE SHALL NOT BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR
CONSEQUENTIAL DAMAGES OR LOSSES, INCLUDING LOSS OF DATA, WHETHER
ARISING FROM BREACH OF WARRANTY OR BASED ON CONTRACT, TORT, RELIANCE OR
ANY OTHER THEORY.
Since some countries or states do not allow limitation of the term of an implied warranty, or
exclusion or limitation of incidental or consequential damages, the limitations and exclusions of
this warranty may not apply to every buyer. If any provision of this Warranty is held invalid or
unenforceable by a court of competent jurisdiction, such holding will not affect the validity or
enforceability of any other provision.
Fluke Corporation Fluke Europe B.V.
P.O. Box 9090 P.O. Box 1186
Everett WA 5602 B.D. Eindhoven
98206-9090 The Netherlands
5/94

SAFETY TERMS IN THIS MANUAL
This instrument has been designed and tested in accordance with IEC publication
1010-1 (1992-1), Safety Requirements for Electrical Measuring, Control and Laboratory
Equipment, and ANSI/ISA-582.01-1994, and CAN/CSA-C22.2 No. 1010.1-92. This User
Manual contains information, warning, and cautions that must be followed to ensure
safe operation and to maintain the instrument in a safe condition. Use of this equipment
in a manner not specified herein may impair the protection provided by the equipment.
This instrument is designed for IEC 1010-1 Installation Category II use. It is not
designed for connection to circuits rated over 4800 VA.
WARNING statements identify conditions or practices that could result in personal injury
or loss of life.
CAUTION statements identify conditions or practices that could result in damage to
equipment.
SYMBOLS MARKED ON EQUIPMENT
WARNING Risk of electric shock. Refer to the manual.
GROUND Ground terminal to chassis (earth).
Attention Refer to the manual. This symbol indicates that information
about usage of a feature is contained in the manual. This symbol
appears on the rear panel ground post and by the fuse compartment.
AC POWER SOURCE
The instrument is intended to operate from an ac power source that will not apply more
than 264V ac rms between the supply conductors or between either supply conductor
and ground. A protective ground connection by way of the grounding conductor in the
power cord is required for safe operation.
USE THE PROPER FUSE
To avoid fire hazard, for fuse replacement use only the specified unit: 15/100 ampere,
250V, time delay.
GROUNDING THE INSTRUMENT
The instrument utilizes controlled overvoltage techniques that require the instrument to
be grounded whenever normal mode or common mode ac voltages or transient voltages
may occur. The enclosure must be grounded through the grounding conductor of the
power cord, or through the rear panel ground binding post.

USE THE PROPER POWER CORD
Use only the power cord and connector appropriate for the voltage and plug
configuration in your country.
Use only a power cord that is in good condition.
Refer power cord and connector changes to qualified service personnel.
DO NOT OPERATE IN EXPLOSIVE ATMOSPHERES
To avoid explosion, do not operate the instrument in an atmosphere of explosive gas.
DO NOT REMOVE COVER DURING OPERATION
To avoid personal injury or death, do not remove the instrument cover without first
removing the power source connected to the rear panel. Do not operate the instrument
without the cover properly installed. Normal calibration is accomplished with the cover
closed. Access procedures and the warnings for such procedures are contained in this
manual. Service procedures are for qualified service personnel only.
DO NOT ATTEMPT TO OPERATE IF PROTECTION MAY BE IMPAIRED
If the instrument appears damaged or operates abnormally, protection may be impaired.
Do not attempt to operate the instrument under these conditions. Refer all questions of
proper instrument operation to qualified service personnel.

i
Table of Contents
Chapter Title Page
1 Introduction and Specification............................................................ 1-1
1-1. Introduction............................................................................................ 1-3
1-2. Options and Accessories ........................................................................ 1-6
1-3. Instrument Connector Set, 2620A-100 .............................................. 1-6
1-4. Host Computer Ethernet Interfaces.................................................... 1-6
1-5. Interconnection Cables and Components........................................... 1-6
1-6. Operating Instructions............................................................................ 1-7
1-7. Organization of the Service Manual....................................................... 1-7
1-8. Conventions............................................................................................ 1-8
1-9. Specifications......................................................................................... 1-8
1-10. 2640A/2645A Combined Specifications ........................................... 1-8
1-11. 2640A/2645A General Specifications........................................... 1-9
1-12. 2640A/2645A Environmental Specifications................................ 1-10
1-13. 2640A/2645A Input/Output Capabilities....................................... 1-10
1-18. 2640A/2645A Totalizer................................................................. 1-12
1-19. 2640A/2645A Real-Time Clock and Calendar.............................. 1-12
1-20. 2640A Specifications......................................................................... 1-13
1-21. 2640A DC Voltage Measurement Specifications.......................... 1-13
1-22. 2640A AC Voltage Measurement Specifications.......................... 1-14
1-23. 2640A Four-Wire Resistance Measurement Specifications.......... 1-16
1-24. 2640A Two-Wire Resistance Measurement Specifications.......... 1-16
1-25. 2640A Four-Wire RTD per ITS-1990 Measurement
Specifications.............................................. .................................. 1-17
1-26. 2640A Two-Wire RTD per ITS-1990 Measurement
Specifications.............................................. .................................. 1-17
1-27. 2640A Thermocouple per ITS-1990 Measurement
Specifications.............................................. .................................. 1-18
1-28. 2640A Frequency Measurement Specifications............................ 1-19
1-29. 2645A Specifications......................................................................... 1-20
1-30. 2645A DC Voltage Measurement Specifications.......................... 1-20
1-31. 2645A AC Voltage Measurement Specifications.......................... 1-21
1-32. 2645A Four-Wire Resistance Measurement Specifications.......... 1-23
1-33. 2645A Two-Wire Resistance Measurement Specifications.......... 1-23

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1-34. 2645A Four-Wire RTD per ITS-1990 Measurement
Specifications................................................................................. 1-24
1-35. 2645A Thermocouple per ITS-1990 Measurement
Specifications................................................................................. 1-24
1-36. 2645A Frequency Measurement Specifications............................ 1-26
2 Theory of Operation............................................................................. 2-1
2-1. Introduction............................................................................................ 2-5
2-2. Functional Block Description................................................................. 2-5
2-3. A1 Main PCA Block Description ...................................................... 2-7
2-4. Power Supply................................................................................. 2-7
2-5. Digital Kernel ................................................................................ 2-7
2-6. Serial Communication (Guard Crossing) ...................................... 2-8
2-7. Digital Inputs and Outputs............................................................. 2-8
2-8. Ethernet Interface .......................................................................... 2-8
2-9. A2 Display PCA Block Description .................................................. 2-8
2-10. A3 A/D Converter PCA Block Description....................................... 2-8
2-11. Analog Measurement Processor.................................................... 2-9
2-12. Input Protection ............................................................................. 2-9
2-13. Input Signal Conditioning.............................................................. 2-9
2-14. Analog-to-Digital (a/d) Converter................................................. 2-9
2-15. Inguard Microcontroller ................................................................ 2-9
2-16. Channel Selection.......................................................................... 2-9
2-17. Open Thermocouple Check........................................................... 2-10
2-18. A4 Analog Input PCA Block Description.......................................... 2-10
2-19. 20-Channel Terminals ................................................................... 2-10
2-20. Reference Junction Temperature................................................... 2-10
2-21. Detailed Circuit Description .................................................................. 2-10
2-22. A1 Main PCA Circuit Description..................................................... 2-10
2-23. Power Supply Circuit Description................................................. 2-10
2-31. Digital Kernel ................................................................................ 2-13
2-42. Digital Inputs and Outputs............................................................. 2-24
2-48. A2 Display PCA Circuit Description................................................. 2-26
2-49. Main PCA Connector .................................................................... 2-26
2-50. Front Panel Switches..................................................................... 2-27
2-51. Display........................................................................................... 2-28
2-52. Beeper Drive Circuit...................................................................... 2-28
2-53. Watchdog Timer and Reset Circuit............................................... 2-29
2-54. Display Controller ......................................................................... 2-29
2-55. A3 A/D Converter PCA Circuit Description..................................... 2-31
2-56. Stallion Chip.................................................................................. 2-33
2-57. Input Protection ............................................................................. 2-33
2-58. Input Signal Conditioning.............................................................. 2-33
2-59. Function Relays............................................................................. 2-33
2-60. Channel Selection Circuitry........................................................... 2-34
2-61. DC Volts and Thermocouples Measurement Circuitry................. 2-34
2-62. Ohms and RTD Measurement Circuitry........................................ 2-36
2-63. AC Volts Measurement Circuitry.................................................. 2-37
2-64. Frequency Measurements.............................................................. 2-37
2-65. Active Filter (ACV Filter)............................................................. 2-37
2-66. Voltage Reference Circuit............................................................. 2-38
2-67. Analog/Digital Converter Circuit.................................................. 2-39
2-73. Inguard Digital Kernel Circuitry ................................................... 2-42
2-74. Open Thermocouple Detect Circuitry............................................. 2-43

Contents (continued)
iii
2-75. A4 Analog Input PCA Circuit Description........................................ 2-43
2-76. A1 Main to A3 A/D Converter Communications................................... 2-44
2-77. Special Codes..................................................................................... 2-44
2-78. Resets................................................................................................. 2-44
2-79. Commands.......................................................................................... 2-45
2-80. Perform Scan ................................................................................. 2-45
2-81. Perform Self-Test........................................................................... 2-46
2-82. Return Main Firmware Version..................................................... 2-46
2-83. Return Boot Firmware Version ..................................................... 2-47
2-84. Set Global Configuration............................................................... 2-47
2-85. Set Channel Configuration ............................................................ 2-47
2-86. Do Housekeeping........................................................................... 2-48
2-87. Checksums ......................................................................................... 2-48
2-88. Errors.................................................................................................. 2-48
2-89. Power-Up Protocol............................................................................. 2-49
2-90. Inguard Unresponsive ........................................................................ 2-49
2-91. Inguard Software Description ................................................................ 2-49
2-92. Hardware Elements............................................................................ 2-49
2-93. Channel MUX.... ........................................................................... 2-49
2-94. Function Relays. ........................................................................... 2-51
2-95. Stallion Chip and Signal Conditioning.......................................... 2-51
2-96. A/D ................................................................................................ 2-53
2-101. DISCHARGE Signal. .................................................................... 2-57
2-102. Open-Thermocouple Detector. ...................................................... 2-57
2-103. Channel Measurements...................................................................... 2-57
2-104. Reading Rates................................................................................ 2-57
2-105. Measurement Types....................................................................... 2-58
2-112. Autoranging................................................................................... 2-60
2-113. Overload ........................................................................................ 2-61
2-114. Housekeeping Readings..................................................................... 2-61
2-115. Reading Types ............................................................................... 2-61
2-118. Housekeeping Schedule................................................................. 2-62
2-119. Self-Tests ........................................................................................... 2-62
2-120. Power-Up Self-Tests...................................................................... 2-62
2-121. Self-Test Command....................................................................... 2-63
3 General Maintenance........................................................................... 3-1
3-1. Introduction............................................................................................ 3-3
3-2. Warranty Repairs and Shipping ............................................................. 3-3
3-3. General Maintenance.............................................................................. 3-3
3-4. Required Equipment .......................................................................... 3-3
3-5. Power Requirements .......................................................................... 3-3
3-6. Static-Safe Handling.......................................................................... 3-3
3-7. Servicing Surface-Mount Assemblies................................................ 3-4
3-8. Cleaning.................................................................................................. 3-4
3-9. Replacing the Line Fuse......................................................................... 3-5
3-10. Disassembly Procedures......................................................................... 3-7
3-11. Removing the Instrument Case.......................................................... 3-7
3-12. Removing the Front Panel Assembly................................................. 3-7
3-13. Disassembling the Front Panel Assembly.......................................... 3-11
3-14. Removing the A1 Main PCA............................................................. 3-11
3-15. Removing the A2 Display PCA......................................................... 3-12
3-16. Removing the A3 A/D Converter PCA.............................................. 3-12
3-17. Removing the A4 Analog Input PCA ................................................ 3-12

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3-18. Removing Miscellaneous Chassis Components ................................ 3-12
3-19. Removing the Power Switch/Input Connector .............................. 3-12
3-20. Removing the Fuseholder.............................................................. 3-13
3-21. Removing the Power Transformer................................................. 3-13
3-22. Assembly Procedures ............................................................................. 3-13
3-23. Installing Miscellaneous Chassis Components.................................. 3-13
3-24. Installing the Power Transformer.................................................. 3-13
3-25. Installing the Fuseholder ............................................................... 3-14
3-26. Installing the Power Switch/Input Connector................................ 3-14
3-27. Installing the A1 Main PCA............................................................... 3-15
3-28. Installing the A2 Display PCA........................................................... 3-15
3-29. Installing the A3 A/D Converter PCA............................................... 3-15
3-30. Installing the A4 Analog Input PCA.................................................. 3-15
3-31. Assembling the Front Panel Assembly.............................................. 3-16
3-32. Installing the Front Panel Assembly.................................................. 3-16
3-33. Installing the Instrument Case............................................................ 3-16
4 Performance Testing and Calibration................................................. 4-1
4-1. Introduction............................................................................................ 4-3
4-2. Performance Test ................................................................................... 4-3
4-3. Configuring the Performance Test Setup........................................... 4-3
4-4. Initializing the Performance Test Setup............................................. 4-6
4-5. Accuracy Performance Tests ............................................................. 4-7
4-6. Volts DC Accuracy Test (2640A)................................................. 4-8
4-7. Volts DC Accuracy Test (2645A)................................................. 4-9
4-8. Volts AC Accuracy Test................................................................ 4-10
4-9. Frequency Accuracy Test.............................................................. 4-10
4-10. Analog Channel Integrity Test....................................................... 4-11
4-11. Computed Channel Integrity Test.................................................. 4-11
4-12. Thermocouple Temperature Accuracy Test.................................. 4-12
4-13. Open Thermocouple Response Test.............................................. 4-12
4-14. Two-Terminal Resistance Accuracy Test (2640A)....................... 4-13
4-15. Two-Terminal Resistance Accuracy Test (2645A)....................... 4-14
4-16. Four-Terminal Resistance Accuracy Test (2640A)....................... 4-15
4-17. Four-Terminal Resistance Accuracy Test (2645A)....................... 4-17
4-18. RTD Temperature Accuracy Test (Resistance) (2640A).............. 4-18
4-19. RTD Temperature Accuracy Test (Resistance) (2645A).............. 4-19
4-20. RTD Temperature Accuracy Test (DIN/IEC 751 RTD) ............... 4-19
4-21. Digital Input/Output Tests ................................................................. 4-20
4-22. Digital I/O Output Test.................................................................. 4-20
4-23. Digital Input Test........................................................................... 4-21
4-24. Totalizer Tests........................................................................................ 4-22
4-25. Totalizer Count Test...................................................................... 4-22
4-26. Totalizer Sensitivity Test............................................................... 4-23
4-27. Master Alarm Output Test................................................................. 4-23
4-28. Trigger Input Test .............................................................................. 4-24
4-29. Trigger Output Test............................................................................ 4-24
4-30. Calibration.............................................................................................. 4-25
4-31. Methods of Calibration...................................................................... 4-25
4-32. Preparing for Calibration ................................................................... 4-26
4-33. Ending Calibration............................................................................. 4-28
4-34. RS-232 Instrument Configuration Parameters................................... 4-28
4-35. Calibration Procedure (Automatic).................................................... 4-28
4-36. Calibration Procedure (Semiautomatic)............................................. 4-28

Contents (continued)
v
4-37. VDC Calibration Procedure........................................................... 4-31
4-38. VAC Calibration Procedure........................................................... 4-32
4-39. Resistance Calibration Procedure.................................................. 4-33
4-40. Frequency Calibration Procedure.................................................. 4-34
4-41. Calibration Procedure (Manual) ........................................................ 4-34
4-42. Manual Calibration Commands..................................................... 4-36
4-43. Manual VDC Calibration Procedure ............................................. 4-37
4-44. Manual VAC Calibration Procedure ............................................. 4-38
4-45. Manual Resistance Calibration Procedure..................................... 4-39
4-46. Manual Frequency Calibration Procedure..................................... 4-41
5 Diagnostic Testing and Troubleshooting........................................... 5-1
5-1. Introduction............................................................................................ 5-3
5-2. Servicing Surface-Mount Assemblies.................................................... 5-3
5-3. Error Detection....................................................................................... 5-4
5-4. FLASH ROM Parameter Defaults..................................................... 5-5
5-5. Background Testing........................................................................... 5-5
5-6. Internal Software Errors..................................................................... 5-6
5-7. Retrieving Error Codes using RS-232................................................ 5-6
5-8. Retrieving Error Codes using the Network........................................ 5-6
5-9. Selecting the Diagnostic Tools............................................................... 5-6
5-10. Diagnostic Tool dio............................................................................ 5-7
5-11. Diagnostic Tool idS ........................................................................... 5-7
5-12. Diagnostic Tool conF......................................................................... 5-8
5-13. Diagnostic Display Test..................................................................... 5-9
5-14. COMM Parameter Reset.................................................................... 5-9
5-15. Using the RS-232 Interface.................................................................... 5-9
5-16. Command Processing......................................................................... 5-10
5-17. Instrument Configuration................................................................... 5-11
5-18. Command Set ......................................................................................... 5-12
5-19. Troubleshooting the Instrument ............................................................. 5-19
5-20. General Troubleshooting ................................................................... 5-19
5-21. A1 Main PCA Troubleshooting......................................................... 5-27
5-22. Troubleshooting the A1 Main PCA Digital Kernel....................... 5-27
5-23. Troubleshooting the RS-232 Interface........................................... 5-28
5-24. Troubleshooting the Ethernet Interface......................................... 5-28
5-25. Troubleshooting the Digital I/O Lines and Trigger Out Lines...... 5-28
5-26. Troubleshooting the Totalizer and Trigger In Lines ..................... 5-28
5-27. Troubleshooting the Power Supply ............................................... 5-29
5-28. A2 Display PCA Troubleshooting..................................................... 5-29
5-29. Variations in the Display............................................................... 5-31
5-30. A3 A/D Converter PCA Troubleshooting.......................................... 5-31
5-31 A3 Kernel. ..................................................................................... 5-32
5-32. Break/Reset Circuit........................................................................ 5-32
5-33. Out of Tolerance Readings............................................................ 5-32
5-34. Troubleshooting Relay Problems .................................................. 5-33
5-35. A4 Analog Input PCA Troubleshooting ............................................ 5-33
5-36. Troubleshooting Calibration Failures .................................................... 5-34
5-37. Retrieving Calibration Constants....................................................... 5-34
5-38. Loading Embedded Instrument Firmware.............................................. 5-36
5-39. Firmware Diskette.............................................................................. 5-36
5-40. Loading the Main Firmware .............................................................. 5-37
5-41. Loading the A/D Firmware................................................................ 5-38

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6 List of Replaceable Parts .................................................................... 6-1
6-1. Introduction............................................................................................ 6-3
6-2. How To Obtain Parts.............................................................................. 6-3
6-3. Manual Status Information..................................................................... 6-3
6-4. Newer Instruments.................................................................................. 6-4
6-5. Service Centers....................................................................................... 6-4
7 Schematic Diagrams............................................................................ 7-1