Front-Panel Operation
Controlling Trigger Functions
3
3-17
Note
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.
Note
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.
If the Meter does not receive a trigger for a few seconds, a
TRIG
annunciator
illuminates indicating the Meter is waiting for a trigger and a lightning bolt appears
indicating the Meter does not know what voltage is applied to the terminals. Each
press of the trigger key
W
or an active low pulse on the trigger port will initiate a
measurement.
Setting the Trigger Delay
A Meter measurement can be delayed a set amount of time after receiving a trigger. This
feature may be useful when you need to wait for a signal to settle before measuring it.
When a trigger delay is specified, that delay is used for all functions and ranges.
To set a trigger delay:
1.
Press
L
.
2.
Press the soft key labeled
TRIGGER
.
3.
Press the soft key labeled
SET DELAY
.
The trigger delay can be set between 0 and 3600 seconds with a resolution of 10
microseconds.
Summary of Contents for 8845A
Page 6: ...8845A 8846A Users Manual iv...
Page 8: ...8845A 8846A Users Manual vi...
Page 10: ...8845A 8846A Users Manual viii...
Page 12: ...8845A 8846A Users Manual 1 2 Diode Test 1 22 Measurement Rates IEEE488 4 1 22...
Page 34: ...8845A 8846A Users Manual 2 2...
Page 42: ...8845A 8846A Users Manual 2 10...
Page 70: ...8845A 8846A Users Manual 4 2...
Page 88: ...8845A 8846A Users Manual...
Page 90: ...8845A 8846A Users Manual A 2...
Page 96: ...8845A 8846A Users Manual C 2...
Page 102: ...8845A 8846A Users Manual 4...