Trigger source

These commands enable you to disable the trigger, select the trigger source from one of the eight VXI backplane triggers or to select an external trigger. For external triggering, connect a TTL trigger signal to the TRIGGER INPUT connector. Ensure however, that this socket is not disabled for your application by a higher priority mode having been selected. The order of priority is as follows:

FSK logic input Memory sequencing Sweep trigger

All three modes of operation may be enabled at the same time, but only one mode will be active, the one with the highest priority. Therefore ensure that, for example, FSK and memory sequencing are not enabled when selecting sweep triggering otherwise the triggering will have no effect. Trigger source selection is as follows:

TRIGGER

:SOURCE

Select trigger source.

Data type : Character Program Data (HOLD, IMMEDIATE, TTLTRG0, TTLTRG1, TTLTRG2, TTLTRG3, TTLTRG4, TTLTRG5, TTLTRG6, TTLTRG7, BUS, EXTERNAL). HOLD means no trigger.

Allowed suffices :

None

 

Default suffix :

None

 

Example:

TRIGGER:SOURCE EXTERNAL

TRIGGER:SOURCE?

Prepares message containing information on Trigger Source setting in

 

the following format:

 

:TRIGGER:SOURCE <source>

 

where

<source> is character program data defining the trigger

 

 

source.

Examples:

:TRIGGER:SOURCE EXTERNAL

 

:TRIGGER:SOURCE TTLTRG3

Sources

BUS:

The trigger is generated over the GPIB or VXI interface. The group execute

 

trigger (GET) provides the trigger over IEEE 488.1

HOLD:

Selecting this means the event detection is disabled.

IMMEDIATE:

No waiting for an event to occur.

TTLTRG 0-7:

The VXI backplane TTLTRG triggers provide the source.

EXTERNAL:

An external trigger is provided via the TRIGGER INPUT socket.

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VXI 3002 manual Trigger source, Sources, Triggersource?