Keithley 2000, User Manual, Page: 66 / 280

External trigger
The EXT TRIG input requires a falling-edge, TTL-compatible pulse with the specifications
shown in Figure 3-4. In general, external triggers can be used to control measure operations. For
the Model 2000 to respond to external triggers, the trigger model must be configured for it.
Voltmeter complete
The VMC output provides a TTL-compatible output pulse that can be used to trigger other
instruments. The specifications for this trigger pulse are shown in Figure 3-5. Typically, you
would want the Model 2000 to output a trigger after the settling time of each measurement.
External triggering example
In a typical test system, you may want to close a channel and then measure the DUT connect-
ed to the channel with a multimeter. Such a test system is shown in Figure 3-6, which uses a
Model 2000 to measure ten DUTs switched by a Model 7011 multiplexer card in a Model 7001/
7002 Switch System.
Triggers on
Leading Edge
TTL High
(2V-5V)
TTL Low
(
≤
0.8V)
2µs
Minimum
Meter
Complete
TTL High
(3.4V Typical)
TTL Low
(0.25V Typical)
10µs
Minimum
Figure 3-5
Trigger link out-
put pulse specifi-
cations (VMC)
3-12 Measurement Options
Figure 3-4
Trigger link input
pulse specifica-
tions (EXT TRIG)