BNC 845-M - Manual (Page 42)

42
Model 845-M Programmer’s Manual V1.1 2011
:TRIGger Subsystem
Triggers control the playback by telling the Model 845-M when to play the signal.
Depending on the trigger settings for the Model 845-M, the waveform playback can occur once,
continuously, or the 845-M may start and stop playing the waveform repeatedly (GATE mode). A
trigger signal comprises both positive and negative signal transitions (states), which are also called
high and low periods. You can configure the 845-M to trigger on either state of the trigger signal. It is
common to have multiple triggers, also referred to as trigger occurrences or events, occur when the
signal generator requires only a single trigger. In this situation, the Model 845-M recognizes the first
trigger and ignores the rest.
When you select a trigger mode, you may lose the signal from the RF output until you trigger the
waveform.
There are four parts to configuring the trigger:
1. Choosing the trigger type which controls the waveform’s transmission.
x NORMal : trigger edge initiates/stops sweeps
x GATE : trigger level starts/stops sweep
2. Setting the waveform’s response to triggers:
— CONTinuous : reapeatedly accepts trigger events
— SINGle : uses only one trigger event
3. Selecting the trigger source which determines how the Model 845-M receives its trigger signal,
internally or externally. The GATE choice requires an external trigger.
3. Setting the trigger polarity when using an external source
Command Parameters Unit
(default)
Remark
TRIGger[:SEQuence]:TYPE NORMal|GATE|POINt N/A V0.3.10
TRIGger[:SEQuence]:TYPE:GATE LOW|HIGH HIGH V0.3.10
TRIGger[:SEQuence]:SOURce IMMediate|KEY|EXT|BUS IMM V0.3.10
TRIGger[:SEQuence]:DELay <value> 0 s V0.3.10
TRIGger[SEQuence]:SLOPe POSitive|NEGative POS V0.3.10
TRIGger[SEQuence]:RETRigger ON|OFF|IMMediate OFF V0.3.10
[SOURce]:TRIGger[:SEQuence]:ECOunt <value> 1 V0.3.10
[SOURce]:TRIGGer[:SEQuence]:OUTPut:POLarity
[SOURce]:TRIGGer[:SEQuence]:OUTPut:MODE
NORMal|INVerted
NORMal|GATE|POINt
NORM
?
V0.3.10
V0.3.10
:TRIGger:TYPE
TRIGger[:SEQuence]:TYPE NORMal | GATE | POINT
TRIGger[:SEQuence]:TYPE?
This command sets the trigger type that controls the waveform’s playback.
The following list describes the trigger type command choices:
NORMal Upon triggering, the waveform sequence plays according to settlings defined by
:INITiate:CONTinuous
(only once or repeatedly)
GATE An external trigger signal repeatedly starts and stops the waveform’s playback. The
time
duration for playback depends on the duty period of the trigger signal and the
gate polarity selection. The waveform plays during the inactive state and stops during