HP 8-Channel 196 kSa/sec Digitizer plus DSP E1433A manual Arm and Trigger

HP E1433A User's Guide

The C-Language Host Interface Library

Arm and Trigger

This section explains some terminology relating the the “Arm” and “Trigger” steps in the measurement loop. As an example a measurement might be set up to arm at a certain RPM level and then subsequently trigger at an external event corresponding to top dead center (TDC). The settings would be:

￿	Arm:	RPM Step Arm
￿	Trigger:	External Trigger

If you want to begin a throughput session at this same RPM/TDC event, then the first external trigger after a specified RPM would start a continuous mode measurement. Now (using overlap block mode) the settings would be:

￿ Pre-Arm:	RPM Step Arm
￿ Arm:	Auto
￿ Trigger:	Auto

In the measurement loop, an arm must take place before a trigger. You can program how many triggers to do before waiting for another arm condition. The default is one trigger for each arm. For each trigger, a block of data is sent to the host.

The first arm in a measurement is the pre-arm. By default, the pre-arm condition is the same as the regular arm conditions.

Valid Arm (and Pre-Arm) conditions are:

￿Auto Arm

￿Manual Arm

￿RPM Step Arm

Valid trigger conditions are:

￿Auto Trigger

￿Input Trigger

￿Source Trigger

￿External Trigger

￿Manual Trigger

￿Tachometer Edge Trigger

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