API Commands Appendix A
A-54 ChartScan User’s Manual
T - Set Trigger Configuration
TYPE Acquisition
EXECUTION Deferred
SYNTAX Tstart,
stop,
re-arm,
sync
Configure an acquisition of scan data with the following parameters:
start is the start event
stop is the stop event
re-arm determines if the unit should continue acquiring after the first
acquisition completes, where 1 is on and 0 is off.
sync determines if acquisition events should be synchronized with the
internal timebases, where 1 is on and 0 is off.
T? Query the present trigger configuration
DESCRIPTION
The Set Trigger Configuration (T) command is the central command which controls how an acquisition is t o be
configured. Upon execution of this command the unit enters the acquiring mode. This will be indicated on the
front panel by the flashing of the TRIGGER light. If a pre-trigger has been configured (via the Y command), then
the sampling for pre-trigger data will begin at this time.
Since the Set Trigger Configuration command controls the configuration of an acquisition, all other acquisition
dependent commands should be sent before the Set Trigger Configuration command is sent to the unit . The
commands which should be sent to the unit prior to the Set Trigger Configuration command will depend on the
desired start and/or stop triggers. For instance, if configuring for Trigger on Command, it would not be neces sary
to send the Set Trigger Level (L) command.
The following table lists the valid trigger types and their associated required prior issue commands.
Start/Stop
Trigger
Type
Start/Stop Trigger Definition Pre-Trigger/
Post Stop
Required Prior Issue
Commands
0None - Event Not Defined (N/A) (N/A)
(N/A) (N/A)
1Trigger on Command(See @ command) yes I,Y
no I
2Trigger on GET (IEEE-488 only) yes I,Y
no I
3Trigger on Talk (IEEE-488 only) yes I,Y
no I
4Trigger on Channel Above Level (L command) yes I,Y,L
no I,L
5Trigger on Channel Below Level (L command) yes I,Y,L
no I,L
6Trigger on TTL Signal Rising yes I,Y
no I
7Trigger on TTL Signal Falling yes I,Y
no I
8Trigger on Count (Y command) — I,Y
9Trigger on Alarm Turning On (C command) yes I,Y,C,A (A is optional)
no I,C,A (A is optional)
10 Trigger on Alarm Turning Off (C command) yes I,Y,C,A (A is optional)
no I,C,A (A is optional)
11 Trigger on Absolute Time (P command) yes I,Y,P
no I,P
Note: If the start and stop triggers are of different types, a combination of the start and s top prior issue
commands is required.
The Set Trigger Configuration (T) command is used to configure the manner in which scans are to be acquired.
It sets the sources to determine when an acquisition is to be initiated and when it is to be terminat ed. It also
determines how these acquisition sources are to be (if at all) synchronized with the internal scan intervals (I)
command. Likewise, it may allow the acquisition to re-enable itself (with the same confi guration) after the initial
acquisition has been terminated.