Keithley 617 User Manual

3.10.5 Baseline Suppression (N)
HP45 Programming Example-To enable baseline sup-
pression, type in the following lines:
The baseline suppression mode allows a stored offset value to
REMOTE 727 (END LINE)
be subtracted from subsequent readings. When the suppres-
CXJTl’UT 727;“Nlx” (END LINE)
sion mode is enabled with the appropriate command, the in-
strument will internally store the baseline value with the next
When the END LINE key is pressed the second time, the
triaered conversion. All subsequent readings will be the dif-
baseline suppression mode is enabled.
f&&e between the stored b&line value and the actual
signal level. For example, if 1OOmV is stored as a baseline,
that value will be subtracted from the following readings. See
Model 8573 Programming Example-Type the following
paragraph 2.11.2 for a complete description.
commands into the HP-85 keyboard in order to enable
baseline suppression:
To use baseline suppression, perform the following steps:
V% =l:CALL IBSRE(BRDO%,V%) (return)
CMD$=“NlX”:CALL IBWRT(M617%,CMD$) (return)
1. Cancel baseline suppression by sending NOX if already
enabled.
The baseline suppression mode will be enabled when the
2. Select a range and function consistent with the expected
return key is pressed the second time.
measurement,
..-..I....U
The voltage present on the input terminals
may be larger than the displayed value. For
3. Connect the signal to be used as a baseline to the instru-
ment input.
example, if a 150VDC baseline is stored. an
WllmuIuc
applied voltage of +175V will result in a
displayed reading of only +25V
mand control whether the front panel display shows the elec- ?r the front panel display shows the elec-
trometer reading or the voltage source value. Thus, this com- lmg or the voltage source value. Thus, this com-
3.10.5 Display Mode IDI
mand performs essentially the same function as the front ms essentially the same function as the front
The two parameters associated with the display mode com-
panel DISPLAY button. The two display command .AY button. The two display command
parameters are:
4. Enable baseline suppression by sending NlX over the bus.
The baseline will be stored when the command is executed.
5. Disconnect the baseline signal from the instrument and
connect the signal to be measured in its place. Subsequent
readings will be the difference between the baseline and the
applied signal.
NOTES:
1. Baseline suppression reduces the dynamic range of the
measurement. For example, if the stored baseline value is
1oOmV on the 200mV range, an input voltage of 1COmV or
more would overrange the instrument even though
voltages up to 199.99mV are normally within the
capabilities of the 2oOmV range. If the instrument is in the
autorange mode, it will move up range if necessary.
2. Setting the range lower than the stored baseline value will
overrange the instrument.
3. Accurate control over when the baseline is actually stored
may be achieved by placing the instrument in a one shot
trigger mode. Once the desired baseline value is connected
to the instrument, the baseline can be stored by sending
NIX.
4. Function changes cancel baseline suppress. Refer to para-
graph 2.11.2 for details concerning suppress.
DO=Electrometer
Dl = Voltage source
Upon power up, or after receiving a DCL or SDC command,
the instrument will be in the DO (electrometer) mode.
NOTE
When in the Dl mode, sending an electrometer
command (F, R, C, Z, N, or T) will cause the
instrument to revert to the DO (electrometer)
mode.
To program the desired display mode over the bus, you need
only send the appropriate command string. For example,
DlX would be transmitted to view the voltage source value
on the display.
HP-85 Programming Example-Using the front panel
DISPLAY button place the display in the electrometer mode.
Now type in the following lines:
REMOTE 727 (END LINE)
OUTPUT 727;“DlX” (END LINE)
3-22

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