Fluke PM-3384B, PM-3380B, PM-3390B Triggering, Trigger Type, Trigger Source, Trigger Level

3 - 20 USING THE COMBISCOPE INSTRUMENTS

3.4.1.1Triggering

After the measurement is initiated, the CombiScope instrument starts the real acquisition when the trigger conditions are satisfied, e.g., when the selected trigger event occurs. The trigger conditions can be ignored during a specific hold- off time, which can be programmed using the TRIGger:HOLDoff command. During the hold-off time the event detector is inhibited from acting on any trigger.

Trigger Type

The TRIGger:TYPE command selects the type of triggering, which can be programmed to EDGE triggering (normal trigger mode), VIDeo triggering (refer to section 3.4.1.2 "Video triggering"), LOGic, or GLITch triggering. After a *RST command, the trigger type is EDGE.

Note: Logic state, pattern, or glitch settings cannot be programmed using SCPI commands.

Trigger Source

The TRIGger:SOURce command selects the source for the trigger event. The receipt of the GPIB interface message GET (Group Execute Trigger) or the common command *TRG serves as the trigger event when BUS is selected as trigger source.

The trigger event is determined by the AC line voltage when LINE is selected, and is derived from the input signal when INTernal is programmed as trigger source. For the 2-channel CombiScope instruments, EXTernal can be programmed as the trigger source. In that case, channel 4 is selected as external trigger input.

A numeric suffix is used to specify the channel number. For example, TRIGger:SOURce INT2 selects the signal at input channel 2 to trigger the acquisition.

When IMMediate is selected, an acquisition does not wait for a trigger event. So, an INITiate command causes the acquisition to begin immediately. After a *RST command, the trigger source is IMMediate, which means no trigger is required.

Trigger Level

The TRIGger:LEVel command allows you to set the trigger level for all input channels. Programming the trigger level automatically switches off level peak- peak. The trigger level can be programmed only when the TRIGger:SOURce is INTernal. The TRIGger:LEVel:AUTO command allows you to switch level peak- peak on or off. Switching on level peak-peak, deactivates the trigger level. After a *RST command the TRIGger:LEVel is set to its maximum value and level peak- peak is switched off.