Keithley 2000, Руководство пользователя, Страница: 65 / 280

Hold example
1. Enable HOLD, select a window percentage and enter a count.
2. Apply test probes to a signal. Once the signal becomes stable enough to satisfy the hold
condition, the reading is released, and the beeper sounds (if enabled).
3. Remove the hold condition by lifting the probes. Hold will then seek a new “seed”.
External triggering
The EXT TRIG key selects triggering from two external sources: trigger link and the TRIG
key. When EXT TRIG is pressed, the TRIG annunciator lights and dashes are displayed to indi-
cate that instrument is waiting for an external trigger. From the front panel, you can press the
TRIG key to trigger a single reading. Pressing the EXT TRIG key again toggles you back to con-
tinuous triggers.
The Model 2000 uses two lines of the Trigger Link rear panel connector as External Trigger
(EXT TRIG) input and Voltmeter Complete (VMC) output. The EXT TRIG line allows the Mod-
el 2000 to be triggered by other instruments. The VMC line allows the Model 2000 to trigger
other instruments.
At the factory, line 1 is configured as VMC and line 2 as EXT TRIG. (Changing this config-
uration is described in the optional Model 2000 Repair Manual.) A connector pinout is shown
in Figure 3-3.
Rear Panel Pinout
1
2
3 4 5
6 7 8
Pin 2
External
Trigger
Input
Pin 1
Voltmeter
Complete
Output
Pin Number Description
1
2
3
4
5
6
7
8
Voltmeter Complete Output
External Trigger Input
no connection *
Signal Ground
no connection *
no connection *
no connection *
Signal Ground
* Either pin 3 or 5 may be configured as an output instead
of pin 1. Either pin 4 or 6 may be configured as an input
instead of pin 2. See the optional Model 2000 Repair
Manual for details.
Figure 3-3
Rear panel pinout
Measurement Options 3-11