HP 8360 manual Overview, Getting Started Programming

Programming the Trigger System

In This Subsection

Generalized Trigger Model

This subsection discusses the layered trigger model used in SCPI instruments. It also outlines some commonly encountered trigger configurations and programming methods. Trigger system topics are explained in the following paragraphs:

Generalized Trigger These paragraphs explain the structure and

Model	components of the layered trigger model used in
	all SCPI instruments.
Common Trigger	These paragraphs explain the INIT and TRIG
Configurations	configurations implemented in the synthesizer.

Trigger Command These paragraphs provide condensed definitions

Definitions for the keywords used in this subsection.

Understanding trigger systems requires more technical expertise than most other topics covered in this section. If you find this subsection difficult, keep in mind that you do not have to program the trigger system to make measurements or output signals. Using MEASure, READ, or INITiate, you can avoid having to learn the information in this subsection.

Overview

An instrument trigger system synchronizes instrument actions with specified events. An instrument action may be to make a measurement or source an output signal. The events used to synchronize these actions include software trigger commands, changing signal levels, and pulses on BNC connectors.’ The trigger system also lets you specify the number of times to repeat certain actions, and delays between actions.

Figure l-35 shows a simplified view of the generalized SCPI trigger model. Instruments may implement some or all of this model, to accommodate varying needs. Each unshaded block in Figure l-35 represents a particular trigger state. The generalized trigger model allows an arbitrary number of event- detection states. Note that there can be two paths into a state and two paths out of a state. These are called the downward entrance and exit, and the upward entrance and exit. Upward means moving towards the idle state and downward means moving towards instrument actions.

An instrument moves between adjacent states, depending on its internal conditions and the commands that you send. When you first turn on power to an instrument, it is in the idle state. You can force the instrument to the idle state using : ABORt or *RST. The initiate and event detection trigger states are essentially a list of conditions that must be satisfied to reach the adjacent states. The sequence

l-1 04 Getting Started Programming