Introduction; Triggering Measurements - Agilent Technologies 3458A User Manual

Chapter 4

Introduction

Triggering Measurements

This chapter discusses the methods for triggering measurements, the reading
formats, how to use reading memory, and how to transfer readings across the
bus. This chapter also discusses how to increase the reading rate and GPIB
bus transfer speed, how to measure the reading rate, how to use the
multimeter's EXTOUT signal, and how to use the math operations.
Before the multimeter will take readings, three separate events must occur
in the proper order. These events are (1) the trigger arm event, (2) the trigger
event, and (3) the sample event. Sub-sampling (discussed in Chapter 5) and
multiple trigger arming (discussed in this chapter) are the only exceptions to
this triggering hierarchy. As shown in Figure 16, when all three events have
occurred in the order listed, the multimeter begins to make the specified
reading(s). In the power-on state, the multimeter is configured so that it
makes readings automatically; that is, all three events are set to AUTO. For
most applications, you will need to use only one or two of these events and
leave the other event(s) set to AUTO. This section describes the various
events that can be used to satisfy the trigger arm, trigger, and sample event
requirements and contains examples showing how to use these events.
Note
The examples in this manual are intended for Hewlett-Packard Series 200 /
300 computers using BASIC language. They assume a GPIB interface
select code of 7 and a device address of 22 resulting in a combined GPIB
address of 722. Some of the examples in this section store readings in
memory while others transfer readings to the controller. Reading
destination is discussed in detail later in this chapter under "Using Reading
Memory" and "Sending Readings Across the Bus."
Figure 16. Triggering hierarchy
Making Measurements
Chapter 4 Making Measurements 81