Agilent Technologies 3458A User Manual

276 Chapter 7 BASIC Language for the 3458A
itself from the catalog listing of subprograms (CAT command).
SCRATCH The SCRATCH command deletes (scratches) all 3458A subprograms,
variables, and arrays from internal memory. It also deletes all name
definitions from the catalog listing (CAT command). If SCRATCH is
executed when a subprogram is running, an error is generated but the
subprogram is not purged from memory.
CAT The CAT (catalog) command lists the names of all 3458A subprograms,
simple variables, stored states, and arrays that are presently stored in internal
memory. If there are no more arrays or subprograms to be listed, the CAT
command returns the word "DONE". Refer to chapter 3 for more information
on stored states. The format for the catalog is:
For Subprograms:SUB sub_name
For Integer Arrays:IARRAY array_name
For Real Arrays:RARRAY array_name
For Stored States:STATE state_name (non-volatile memory)
For Simple Variables:INT variable_name
REAL variable_name
The following program shows how to use the CAT command.
10 DIM A$[80]
20 OUTPUT 722; "CAT"
30 REPEAT
40 ENTER 722; A$
50 PRINT A$
60 UNTIL A$="DONE"
70 END
LIST The LIST command allows you to list the specified subprogram. Keep in
mind that you cannot edit subprograms from the front panel; you must edit
them from your system controller. The following program shows how to list
the subprogram DMM_CONF to your system controller.
10 DIM A$[100]
20 OUTPUT 722; "LIST DMM_CONF"
30 REPEAT
40 ENTER 722; A$
50 PRINT A$
60 UNTIL A$="SUBEND"
70 END
COMPRESS The COMPRESS command removes the text of the specified subprogram
from internal memory (the subprogram is no longer stored in non-volatile
memory and is lost when power is removed). This saves space in internal
memory but eliminates the ability to list (LIST command) the subprogram.
The COMPRESS command should be used only after the subprogram has
been debugged and tested.

Agilent Technologies 3458A Specifications

General

Model	3458A
Manufacturer	Agilent Technologies
Category	Multimeter
Digits	8.5
Sampling Rate	100, 000 readings/second
Interface	GPIB

Summary

Safety Symbols and Warnings

General Safety Precautions (WARNINGS)

Outlines essential safety precautions for operating, servicing, and repairing the product to prevent injury or damage.

Chapter 2 Getting Started

Operating from the Front Panel

Covers using front panel keys, making measurements, changing functions, and controlling display settings.

Operating from Remote

Explains how to control the multimeter remotely via GPIB, including address management and command sending.

Chapter 3 Configuring for Measurements

General Configuration

Configuring for DC or Resistance Measurements

Details how to configure the multimeter for DC voltage, DC current, and 2-wire or 4-wire resistance measurements.

Configuring for AC Measurements

Explains how to configure the multimeter for AC voltage, AC current, frequency, or period measurements.

Chapter 4 Making Measurements

Triggering Measurements

Explains the three-event triggering hierarchy (arm, trigger, sample) and various event choices.

Using Reading Memory

Sending Readings Across the Bus

Increasing the Reading Rate

Discusses the multimeter's high-speed mode and factors affecting reading rate and transfer speed.

Math Operations

Explains real-time and post-process math operations, enabling/disabling them, and math registers.

Chapter 5 Digitizing

Digitizing Methods

Details DCV, Direct-Sampling, and Sub-sampling methods, summarizing their characteristics and signal paths.

The Sampling Rate

Level Triggering

Describes how to specify voltage and slope for sampling initiation, with examples for DCV and direct-sampling.

DCV Digitizing

Direct-Sampling

Explains direct-sampling using track-and-hold, its bandwidth, and specifying ranges via max._input parameter.

Sub-Sampling

Covers sub-sampling fundamentals, advantages, and how to specify effective interval and number of samples.

Chapter 6 Command Reference

ACAL

Instructs the multimeter to perform self-calibrations (ALL, DCV, AC, OHMS) and discusses autocalibration security.

NRDGS

OFORMAT

PRESET

Configures the multimeter to one of three predefined states: NORM, FAST, or DIG for different operation modes.

SUB

Stores a series of commands as a subprogram, assigning a name for later execution.

TARM

Defines the trigger arm event to enable the trigger event and can be used for multiple measurement cycles.

TEST

Causes the multimeter to perform a series of internal self-tests to check hardware and software integrity.

TRIG

Specifies the trigger event that initiates a measurement, working with TARM and NRDGS.

Chapter 7 BASIC Language for the 3458A

BASIC Language Commands

Subprograms

Explains how to store, execute, and manage BASIC language subprograms for system control and automation.

Appendix B GPIB Commands

TRIGGER (GET)

Appendix C Procedure to Lock Out Front/Rear Terminals and Guard Terminal Switches

Procedure

Outlines the steps for installing the switch lockout kit, including covers and pushrod removal.

Appendix D Optimizing Throughout and Reading Rate

Maximizing the Testing Speed

Covers strategies like tailoring communication paths, program memory, and state storage for optimal testing speed.

DC Volts, DC Current and Resistance

Explains the measurement paths (DCV, track-and-hold) and trade-offs for DC measurements.

AC Volts and AC Current

Details the three ACV measurement techniques (Analog, Synchronous, Random) and their trade-offs.

Frequency and Period

Optimizing the Testing Process Through Task Allocation

Discusses allocating tasks between the DMM and computer using math functions, memory, and program structure.

Math Operations

State Storage and Program Memory

A Benchmark

Appendix E High Resolution Digitizing With the 3458A

Speed with Resolution

Details the multimeter's flexibility in speed and resolution for audio frequency bandwidth.

Digitizing Analog Signals

Avoiding Aliasing

Provides methods to avoid signal distortion caused by aliasing, ensuring accurate waveform representation.

Choice of Two Measurement Paths

Describes the standard DCV path and the track-and-hold path for digitizing and sampling.

Capturing the Data

High Speed Data Transfers

Errors in Measurements