8842A
Page
 Table of Contents
 Remote Programming
8842A
 Measurement Tutorial
 Maintenance
 List of Replaceable Parts
 Schematic Diagrams
 List of Tables
 805-7
 List of Figures
 805-8
 IEEE-488 Interface PCA, Option True RMS AC PCA, Option
 Xii
 Introduction and Specifications
 8842A Digital Multimeter
Options and Accessories
Introduction
 Specifications
 True RMS AC Voltage Option 8842A-09
Peak NM Signal
Rate
Filter
 For Inputs
Frequency
Fundamental Frequency
Crest Factor
 ½ Digits
Current
Full Scale 5½ Digits
 Through Unknown
Range Full Scale Resolution Current ½ Digits
 Hours 23±1C
 Function
Rate Power Line FREQUECNCY1
Automatic Settling Time Delay
Autoranging
 Conversion Time ms 50 Hz 60 Hz 400 Hz
External Trigger Timing Characteristics
 General
Power
 Operating Instructions
 Connecting to Line Power
Installation
Installing the Power-Line Fuse
 Rack Mounting Kits
Adjusting the Handle
 Front and Rear Panel Features
Operating Features
Power-Up Features
 Operating Features
 Local button causes the 8842A to display its
 Rear Panel Features
 Error Messages
Display Features
 Meaning Error Code
Error Code
 Autorange
Diagnostic Self-Tests
Overrange Indication
Ranging
 Triggering
Continuous Trigger Mode
External Trigger Mode
Manual Range
 Sample Complete Output Option -05 Only
Automatic Settling Time Delay
External Trigger Input Option -05 Only
 Measuring Current
Making Measurements
Input Overload Protection Limits
Measuring Voltage and Resistance
 Offset Measurements
 Measuring Voltage and Resistance
External Cleaning
 8842A
 Remote Programming
 Measurement Data Overrange Indication Error Messages
 Capabilities
BUS SET-UP Procedure
 IEEE-488 Address Selection
AN Overview of Remote Operation
 AN Overview of Remote Operation
 ExampleExplanation
DEVICE-DEPENDENT Command SET
 DEVICE-DEPENDENT Command SET
 Device-Dependent Command Set
 Dn Display Commands
Bn Offset Commands
Cn Calibration Commands
 Get Commands
Fn Function Commands
 Meaning
Command Output String
 14. G2 Get Calibration Prompt
12. G0 Get Instrument Configuration
13. G1 Get SRQ Mask
 16. G4 Get Calibration Status
15. G3 Get User-Defined Message
 18. G6 Get YW Status
19. G7 Get Error Status
17. G5 Get IAB Status
 20. G8 Get Instrument Identification
Numeric Entry Command
Put Commands
23. P0 Put Instrument Configuration
 25. P2 Put Calibration Value
24. P1 Put SRQ Mask
 26. P3 Put User-Defined Message
Rn Range Commands
Sn Reading Rate Commands
 Trigger Selection Logic Diagram
Tn Trigger Mode Commands
 33. Z0 Self-Test Command
Wn Terminator Commands
31. X0 Clear Error Register Command
Yn Suffix Commands
 Input Syntax
Device-Clear Command
35. ? Single-Trigger Command
 Input Processing
Definitions
 Interface Messages
ERROR-PRODUCING Characters
DEVICE-DEPENDENT Messages
 Incorrect example
Syntax Rules
 Loading Output Data
Output Data
 Measurement Data
Numeric Data and Error Messages
Overrange Indication Error Messages
Types of Output Data
 Output Priority
Error Messages
Overrange Indication
Status Data
 Serial Poll Register
Service Requests
 Set
SRQ Mask
 Address Messages
Universal Commands
Interface Messages
 Addressed Commands
TALK-ONLY Mode
 Timing Considerations
Immediate Mode Commands
Remote Calibration
 Example Programs
Immediate-Mode Commands for Various Controllers
 Example Programs
 10. Example Program Taking Readings with Local Control
 11. Example Program Using the Serial Poll Register
 12. Example Program Record Errors During Selftest
 13. Example Programs Using the IBM PC
 14. Example Programs Using the IBM PC
 F3-1402.wmf
 F3-1403.wmf
 F3-1404.wmf
 F3-1405.wmf
 F3-1406.wmf
 F3-1407.wmf
 F3-1408.wmf
 F3-1409.wmf
 F3-1410.wmf
 F3-1411.wmf
 ASCII/IEEE Std 488-1978 Bus Codes
 8842A
 Measurement Tutorial
 DC Voltage Measurement
Circuit Loading Error
 Measuring Input Bias Current Error
Input Bias Current Error
 Resistance Measurement
Wire Ohms
 Correcting for Test Lead Resistance in 2-Wire Ohms
 Full Scale Voltage
Test Current
 Applications of the Ohms Functions
Testing Diodes
Testing Electrolytic Capacitors
 Precision Current Source
DC Current Measurement
 Reducing Thermal Voltages
Burden Voltage Error Calculation
 Waveform Comparison
AC Voltage and Current Measurement
True RMS Measurement
 AC Voltage and Current Measurement
 AC-Coupled AC Measurements
Crest Factor
 Bandwidth
Zero-Input VAC Error
Combined AC and DC Measurements
 20Ω Ranges
Reduction of Zero-Input Error
 10. Shielding for Low Voltage Measurements
Making Accurate HIGH-RESISTANCE Measurements
 12. Leakage Resistance in High Resistance Measurement
 Theory of Operation
 True RMS AC Option VAC Scaling MA AC Scaling
 Overall Functional Description
 DC Scaling
Detailed Circuit Description
 DC Scaling
 DC Scaling VDC and mA DC
VDC Scaling
 Analog Filter
VDC Protection
MA DC Scaling
 Track/Hold Amplifier
TRACK/HOLD Circuit
 TRACK/HOLD Circuit
 Timing Diagram for One A/D Cycle
Track Configuration
 Precision Voltage Reference
Settling Configuration
Hold Configuration
Pre-Charge Configuration
 Ohms Current Source
Ohms Current Source
 Ohms Functions
Ohms Protection
 Ohms Scaling
 20. A/D Converter
 Analog-to-Digital Converter
 Precision DAC
Timing/Data Control
 23. A/D Amplifier
Bootstrap Supplies
Display
 Digital Controller
Keyboard
 13. Digital Controller Block Diagram
 In-Guard Microcomputer
 14. Read/Write Timing Diagrams for Internal Bus
 Calibration Correction
Slow Medium Fast Power Line Frequency
Function and Range Control
30. A/D Control and Computation
 Guard-Crossing Communication
Troubleshooting Modes
Guard Crossing
Keyboard/Display Control
 Power Supply
 Bus Interface Circuitry
IEEE-488 Interface Option
Out-Guard Microcomputer
Guard Crossing
 VAC Scaling
Signal Conditioning
IEEE-488 Interface Power Supply
 True RMS AC-to-DC Conversion
MA AC Scaling
Frequency Response Trimming
 Static awareness
 Dow Chemical
 Maintenance
 External Trigger Polarity Selection Option -05 Only
 Instrument Type
Minimum Specifications Recommended Model
 Frequency Range Minimum Required Accuracy All Ranges
Performance Test
 DC Voltage Test
 Slow Medium Fast MIN MAX
Step Range Input
 Voltage Frequency
AC Voltage Test Option -09 Only
 New Offset must be stored for each new range selected
Resistance Test
 Fast MIN MAX
DC Current Test
Displayed Reading
Slow Medium MIN MAX
 Input Current Frequency
Calibration
AC Current Test Option -09 Only
Step Number Range
 Initial Procedure
Basic Calibration Procedure
 Calibration Functions
12. A/D Calibration
 Step Input
L O W a B L E Error
Step Displayed Prompt
 Displayed Prompt VDC VAC1
Offset and Gain Calibration
Step
 HIGH-FREQUENCY AC Calibration
 Step Displayed PROMPT1,2
Advanced Features and Special Considerations
Storing Variable Inputs
 Verifying Calibration
Procedure Function LOW Prompt High Prompt
Calibrating Individual Ranges
 Tolerance Check
Erasing Calibration Memory
 Tolerance
AC Calibration AT Other Frequencies
Optimizing USE of the 5450A
Calibration
 Optimizing Use of the 5450A
Remote Calibration
 Comments
Front Panel Feature
Corresponding Command
 8842A
 Timing Considerations
 Example Calibration Program
Remote Erasure
 Example A/D Calibration Program
Disassembly Procedure
 Case Removal
A Disassembly
 F6-062.wmf
 F6-063.wmf
 F6-064.wmf
 Main PCA Removal
True RMS AC PCA Removal Option -09 Only
IEEE-488 Interface PCA Removal Option -05 Only
 Maintenance
 Front Panel Disassembly
Reassembly Procedure
 Reassembly Procedure
 Front Panel Disassembly
 Removing the Display Window
 Initial Troubleshooting Procedure
Internal Fuse Replacement
Troubleshooting
 Troubleshooting
 16. Overall State Table
 T6-162.wmf
 17. Circuitry Tested by the Analog Self-Tests
 Diagnostic Self-Tests
 Test Point Voltage
Self-Test Descriptions
Test Number
 Maintenance
 8842A
 IN-GUARD Microcomputer System
Digital Controller Troubleshooting
 In-Guard Microcomputer
 Address Latch U219
 Display System
Calibration Memory U220
 Display Control U212
 To-8 Strobe Decoder U213
 Analog Control Signals
 Device REF. DES
Evaluating Static Signals
 21. Analog Control Logic States
 DC Scaling Troubleshooting
Evaluating Dynamic Signals
 Supply Voltage
PIN or Device
 Ohms Current Source Troubleshooting
Track/Hold Troubleshooting
 13. Typical Output Waveforms for Track/Hold Circuit TP103
 Precision Voltage Reference Troubleshooting
 14. Output of A/D Amplifier TP101
66. A/D Converter Troubleshooting
 15. Waveforms at U101-24 and U101-25
 For fire protection, use exact fuse replacement only
Power Supply Troubleshooting
 17. Waveforms at TP102 for Several Inputs on 2V DV Range
 Minimum Maximum
Test Point
 Diagnostic Program
IEEE-488 Interface Troubleshooting Option
Service Position
 Switches Configuration
Troubleshooting
 Port BIT
True RMS AC Troubleshooting Option
 Defective Stage
Major Problems
Defective Ranges
 Voltage AT TP802
Input Voltage
Voltage AT TP801
 More Obscure Problems
 Cleaning Printed Circuit Assemblies
Internal Cleaning
Guard Crossing Troubleshooting
 21. Guard Crossing Test Waveforms
Cleaning After Soldering
 8842A
 List of Replaceable Parts
 8842A
 Manual Status Information
HOW to Obtain Parts
 Newer Instruments
Service Centers
 Revision Level
Assembly Fluke Part no
REF of Option no
 F7-011.wmf
 F7-012.wmf
 F7-013.wmf
 F7-014.wmf
 A1 Main PCA
 CABLE, Display HEADER,1 ROW,.156CTR,6 PIN
 8842A
 F7-03.wmf
 A2 Display PCA
 F7-03.wmf
 Supply Codes for Manufacturers
 Supply2.wmf
 Service Centers
 Service2.wmf
 8842A
 Options and Accessories
 8842A
 Number Option
Model
Description
 Accessories
 High Voltage Probes 80K-6 and 80K-40
Current Shunt 80J-10
Current Probes Y8100, Y8101, 80i-400
 8842A
 Option -05 IEEE-488 Interface
 805-2
 External Controls
 List of Replaceable Parts
Maintenance
Programming Instructions
 List of Replaceable Parts
 805-6
 805-7
 805-8
 Option -09 True RMS AC
 809-2
 Option -09 True RMS AC
 Operating Instructions
 809-5
 Option -09 True RMS AC PCA
 809-7
 809-8
 Schematic Diagrams
 8842A
 Schematic Diagrams
 F9-012.wmf
 Main PCA, A/D Converter
 F9-022.wmf
 Main PCA, Ohms Current Source
 F9-032.wmf
 Main PCA, Digital
 F9-042.wmf
 Main PCA, Power Supply
 F9-052.wmf
 Display PCA
 F9-062.wmf
 F9-071.wmf
 F9-072.wmf
 IEEE-488 Interface PCA, Option
 IEEE-488 Interface PCA, Option -08