Keithley 617 User Manual

device. When the instrument is in the talk-only mode, the
front panel TALK LED will turn on.
The instrument can be placed in the talk-only mode by enter-
ing one of the following parameters in the primary address
program:
40 Talk only mode with prefix on data string (Example:
NDCV--1.2345E-01
41 Talk only mode without prefix on data string (Example:
-1.2345E-01
To place the instrument in the talk-only mode, perform the
following steps:
1. Press the PROGRAM SELECT button so that the follow-
ing message is displayed:
IEEE 27
2. Press the up arrow V-SOURCE ADJUST button repeated-
ly until the desired talk-only parameter (40 or 41) is
shown.
3. To exit the program, press SHIFT then SELECT EXIT. The
unit is now programmed for the talk-only mode, and it
will remain programmed in this manner even if the power
is turned off.
The data output rate in the talk-only mode can be selected as
follows:
1. Press and hold the DATA STORE ON/OFF button until
the desired rate is displayed, as indicated below.
Displayed r Value/Data Output Rate
r=O
r=l
r=2
r=3
r=4
r=5
r=6
Conversion Rate (Every 36Omsec)
One reading per second
One reading every 10 seconds
One reading per minute
One reading every 10 minutes
One reading per hour
On reading each time TRIG is pressed
2. Press the PROGRAM SELECT button until the IEEE pro-
gram message is displayed and then release the button.
Select the desired IEEE-488 talk-only parameter (40 or 41)
using an ADJUST button.
3. Press SELECT EXIT to return to normal operation. The in-
strument will then enter the talk-only mode and output
readings over the IEEE-488 bus at selected intervals.
3.8 SOFIWARE CONSIDERATIONS
There are a number of IEEE-488 controllers available, each of
which has its own programming language. Also, different in-
struments have differing capabilities. In this section, we will
discuss programming languages for two typical controllers:
the HP-85, and the IBM-PC interfaced to the bus through a
Keithley Model 8573 IEEE-488 interface. In addition, interface
functions codes that define Model 617 capabilities will be
discussed.
3.8.1 Controller Handler Software
Before a specific controller can be used over the IEEE-488 bus,
it must have IEEE-488 handler software installed. With some
controllers, the software is located in ROM, and no software
initialization is required on the part of the user. With other
controllers, software must be loaded from disk or tape and be
properly initialized. With the HP-85, for example, an addi-
tional I/O ROM that handles interface functions must be in-
stalled. With the Keithley Model 8573 interface for the IBM-
PC, software must be installed and configured from a
diskette.
Other small computers that can be used as IEEE-488 con-
trollers may have limited capabilities. With some, interface
programming functions may depend on the interface being
used. Often little software “tricks” are required to obtain the
desired results.
From the preceding discussion, the message is clear: make
sure the proper software is being used with the interface.
Often, the user may incorrectly suspect that the hardware is
causing a problem when it was the software all along.
3.8.2 Interface BASIC Programming
Statements
Many of the programming instructions covered in this section
use examples written with Hewlett Packard Model 85 BASIC
and Model 8573 Interface statements. These computers and
interfaces were chosen for these examples because of their
versatility in controlling the IEEE-488 bus. This section covers
those HP-85 and Model 8573 statements that are essential to
Model 617 operation.
A partial list of HP-85 and Model 8573 statements is shown in
Table 3-6. HP-85 statements have a one or three digit argw
ment that must be specified as part of the statement. The first
310

Keithley 617 Specifications

General

Brand	Keithley
Model	617
Category	Measuring Instruments
Language	English

Summary

Warranty Information

Warranty

Details the warranty terms and conditions for the product and specific components.

Specifications

Specifications

Details the electrical and performance specifications for the Model 617 electrometer.

Safety Precautions

Safety Precautions

Advises on essential safety measures to avoid injury and instrument damage during operation.

Section 1: General Information (Continued)

Unpacking and Getting Started

Details unpacking, inspection, and initial steps to operate the Model 617.

Section 2: Operation

2.2 Power Up Procedure

Details the steps for connecting power and turning on the instrument.

2.3 Power Up Self Test and Display Messages

Explains the self-test routine and potential display messages upon startup.

Section 2: Operation (Continued)

2.4 Front Panel Familiarization

Provides an overview of the Model 617's front panel layout, controls, and indicators.

2.7 Basic Measurement Techniques

Introduces fundamental procedures for making voltage, resistance, charge, and current measurements.

2.7.2 Input Connections

Details how to connect input signals to the rear panel INPUT connector.

2.7.4 Guarded Operation

Explains the concept and application of guarding to minimize leakage and improve measurements.

2.7.5 Making Current Measurements

Details the procedure for measuring low-level currents, including picoampere ranges.

2.7.6 Making Charge Measurements

Describes how to measure charge using the Model 617's coulombs ranges.

2.7.7 Resistance Measurements

Explains how to measure resistance using constant current and voltage methods.

2.8 Using The Voltage Source

Explains how to use the Model 617's built-in voltage source for V/I measurements.

2.10 Using External Feedback

Explains how to extend capabilities using external feedback networks.

2.11 Using Zero Correct and Baseline Suppression

Covers instrument offset cancellation and baseline value storage.

2.11.2 Using Suppression

Details how to store an offset value and subtract it from subsequent readings.

2.13 External Triggering

Explains how to trigger the instrument using external BNC connectors.

2.4.1 Controls

Describes the function and operation of each front panel control button.

2.5.3 Calibration

Introduces the digital calibration program for front panel or IEEE-488 bus use.

2.7.3 Making Voltage Measurements

Provides step-by-step instructions for measuring DC voltages with the Model 617.

2.8.1 Basic Operating Procedure

Guides on connecting and adjusting the voltage source output.

2.11.1 Zero Correct and Zero Check

Explains how to use Zero Correct and Zero Check to cancel internal offsets.

2.12 Data Storage

Describes the internal 100-point data store mode for logging readings.

2.13.1 External Trigger

Details continuous and one-shot triggering modes via the external trigger input.

2.14 Measurement Considerations

Discusses factors affecting measurements at low signal levels.

2.8.2 V/I Resistance Measurements

Describes how to measure high resistances using the voltage source and electrometer.

Section 3: IEEE-488 Programming

Section 3: IEEE-488 Programming (Continued)

3.4 Bus Commands

Covers device commands, grouped into uniline, multiline, and device-dependent categories.

3.7.2 Bus Connections

Details how to connect the Model 617 to the IEEE-488 bus using appropriate cables.

3.7.3 Primary Address Programming

Explains how to check and set the instrument's primary address for bus communication.

3.8 Software Considerations

Discusses software aspects for IEEE-488 controllers like HP-85 and IBM-PC.

3.9 General Bus Command Programming

Covers general bus commands like DCL, REN, IFC, LLO, GTL, SDC, GET, SPE, SPD.

3.10 Device-Dependent Command Programming

Details commands controlling modes like function, range, trigger, and data format.

3.10.2 Function (F)

Describes commands to select measurement functions like Volts, Amps, Ohms, Coulombs.

3.10.3 Range (R)

Explains commands for controlling instrument sensitivity and selecting measurement ranges.

3.10.4 Zero Correct and Zero Check (Z and C)

Details commands for canceling internal offsets and zeroing the instrument.

3.10.5 Baseline Suppression (N)

Explains commands to store an offset and subtract it from subsequent readings.

3.10.9 Voltage Source Value (V)

Details commands for programming the built-in voltage source output.

3.10.10 Voltage Source Operate (O)

3.10.12 Non-Volatile Memory Storage (L)

3.10.14 Trigger Mode (T)

3.10.15 SRQ Mask (M) and Status Byte Format

3.11.2 Number Error

3.4.5 Device-Dependent Commands

Describes commands specific to device configuration, controlling functions like mode and range.

3.10.8 Data Store Mode

Explains how to use the data store for logging readings and setting intervals.

3.10.11 Calibration Value (A)

Describes commands for setting calibration values for ranges and functions.

3.10.18 Status (U)

3.11.1 Bus Error

Section 4: Applications

4.2 Insulation Resistance Measurements

Details how to measure high insulation resistances using constant current and voltage methods.

Section 4: Applications (Continued)

4.3 High Impedance Voltmeter

Explains using the Model 617 as a high-impedance voltmeter with minimal circuit loading.

4.5 Diode Characterization

4.6 Capacitor Leakage Measurements

4.4 Low-Level Leakage Current Measurements

Guides on measuring low-level currents like nanoamperes and picoamperes.

4.7 Capacitance Measurement

4.10 Using The Model 617 With External Voltage Sources

Section 5: Performance Verification

Section 5: Performance Verification (Continued)

5.5 Verification Procedures

Provides detailed procedures for verifying accuracy of volts, ohms, amps, and coulombs functions.

5.5.3 Coulombs Verification

5.5.4 Volts Verification

5.5.5 Ohms Verification (2kΩ–20MΩ Ranges)

5.5.7 Voltage Source Verification

5.5.1 Input Current Verification

5.5.6 Ohms Verification (200MΩ and GΩ Ranges)

5.5.2 Amps Verification

Section 7: Maintenance

7.2 Line Voltage Selection

Section 7: Maintenance (Continued)

7.3 Fuse Replacement

7.4.5 Front Panel Calibration

Provides step-by-step instructions for calibrating from the front panel.

7.4.7 Calibration Sequence

7.4.11 Amps Calibration

Provides calibration steps for the amps function across various ranges.

7.4.12 Coulombs Calibration

Details the procedure for calibrating the coulombs function.

7.4.14 Ohms Calibration

Provides calibration steps for the ohms function across various ranges.

7.4.15 Voltage Source Calibration

Details the procedure for calibrating the instrument's internal voltage source.

7.6 Disassembly Instructions

7.7.2 Power Up Self Test

7.7.7 A/D Converter and Display

7.7.8 Input and Ranging Amplifiers

7.4 Calibration

Introduces digital calibration capabilities and recommendations.

7.4.6 IEEE-488 Bus Calibration

Details procedures for calibrating the instrument via the IEEE-488 bus using a computer.

7.4.8 Input Offset Adjustment

Describes steps to null any small offset in the input amplifier.

7.4.13 Volts Calibration

Outlines the calibration steps for the volts function across different ranges.

7.7 Troubleshooting

Offers guidance for diagnosing and resolving instrument problems.

7.7.3 Self Diagnostic Program

7.4.9 Input Current Adjustment

Details procedures to null input current in the input stage for temperature compensation.

7.4.10 Permanent Storage of Calibration Parameters