IEEE-488 Reference
3-140
:SOURce <name>
:TRACe:FEED:PRETrigger:SOURce <name>
Specify pre-trigger event
Parameters
<name> = EXTernal
Use External Trigger as pre-trigger event
TLINk
Use Trigger Link as pre-trigger event
BUS
Use bus trigger as pre-trigger event
MANual
Use TRIG key as pre-trigger event
Query
:SOURce?
Query pre-trigger event source
Description
This command is used to specify the event for the pre-trigger storage mode. With the pre-trigger
mode selected (:CONTrol, PRETrigger), readings are continuously stored in the buffer while
waiting for the pre-trigger source event.
With EXTernal source selected, an external trigger via the rear panel EXTERNAL TRIGGER
Input provides the pre-trigger event.
With TLINk selected, an input trigger via the Trigger Link provides the pre-trigger event. The
Trigger Link line used for the input trigger is programmed from the Trigger subsystem (see
:TRIGger:TCONfigure command path).
With BUS selected, a GPIB bus trigger (GET or *TRG) provides the pre- trigger event.
With MANual selected, pressing the front panel TRIG key provides the pre-trigger event.
:CONTrol <name>
:TRACe:FEED:CONTrol <name>
Specify buffer control
Parameters
<name> = NEVer
Disables buffer storage
NEXT
Fills buffer and stops
ALWays
Continuously stores readings in buffer
PRETrigger
Use Pretrigger mode to store readings
Query
:CONTrol?
Query buffer control
Description
This command is used to select the buffer control. With NEVer selected, storage into the buffer
is disabled. With any of the other selections, storage is performed as long as buffer feed is not
set for NONE (see :TRACe:FEED NONE). When NEXT is selected, the storage process starts,
fills the buffer and then stops. The buffer size is specified by the :POINts command.
When ALWays is selected, the storage process starts and continues to store readings even after
the buffer fills. After the buffer fills, readings overwrite the previously stored readings.
When PRETrigger is selected, the buffer stores readings continuously (like ALWays) until the
programmed pre-trigger event occurs. When the pre-trigger event occurs, the section of the buff-
er specified for post-trigger readings fill with new readings. The storage process stops when the
post trigger portion of the buffer becomes full with new readings (see :TRACe:FEED:PRETrig-
ger).
