Choosing A Trigger Source - Tektronix DMM4040 User Manual

covered in the Programmers Manual. The following sections discuss triggering the Meter
automatically (internal trigger), or externally using the trigger key on the front panel and
the trigger connector on the rear-panel.
Setup and control of the trigger function is accessible through the Meter's Measurement
Setup key L.

Choosing a Trigger Source

There are four possible sources for triggering a Meter measurement: automatic, front
panel trigger key W, external, and remote. With the exception of remote triggering,
trigger source selection is through the trigger menu, found under the measurement setup
menu.
To select a trigger source:
1. Press L to see the measurement setup menu.
2. Press the TRIGGER soft key to reveal the trigger control selections.
Setting the Meter to trigger via a remote command is only accessible
through the remote interface. See the "Triggering" section in the
Programmers Manual for more information on remote triggering.
Auto Triggering
In auto trigger mode, the Meter's measurements are triggered by internal circuitry. These
triggers are continuous and occur as fast as the configuration will allow. Auto triggering
is the Meter's power-on trigger source.
To return the Meter to auto trigger mode,
1. Press L.
2. Press the soft key labeled TRIGGER. If the Meter is in external trigger mode, the
soft key label EXT TRIG will be highlighted in the display.
3. Press the soft key labeled EXT TRIG.
External Triggering
In the external trigger mode, a Meter measurement starts each time a low-true pulse is
sensed on the external trigger connector or the front-panel trigger key W is pressed. For
each trigger or pulse received, the Meter will take the specified number of measurements
after the specified trigger delay.
The trigger key is disabled whenever the Meter is in Remote mode.
To set up for an external trigger:
1. Press L.
2. Press the soft key labeled TRIGGER.
3. Press the soft key labeled EXT TRIG.
The Ext Trig soft key label will remain highlighted to indicate the Meter is in
external trigger mode. To return to auto trigger mode, press EXT TRIG again.
Note
Note
Front-Panel Operation
Controlling Trigger Functions
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