VXI VT1433B - Manual (Page 100)

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:
q Arm: RPM Step Arm
q Trigger: External Trigger
To begin a throughput session at the same RPM/TDC event, the first external
trigger after a specified RPM would then start a continuous mode measurement.
Now (using overlap block mode) the settings would be:
q Pre-Arm: RPM Step Arm
q Arm: Auto
q Trigger: Auto
In the measurement loop, an arm must take place before a trigger. The number
of triggers that occur before waiting for another arm condition can be specified.
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:
q Auto Arm
q Manual Arm
q RPM Step Arm
Valid trigger conditions are:
q Auto Trigger
q Input Trigger
q Source Trigger
q External Trigger
q Manual Trigger
q Tachometer Edge Trigger
VT1433B User's Guide
The Host Interface Library
4-22