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