Keithley 2700, User Manual, Page: 258 / 500

Model 2700 Multimeter/Switch System User’s Manual Triggering 8-7
Beeper control
The beeper for Hold can be enabled or disabled from the OUTPUT menu as follows:
1. Press SHIFT and then OUTPUT.
2. Use the
Δ
or
∇
key to display the present beeper (BEEP) state; NEVER, OUTSIDE, or
INSIDE.
3. Perform step a or b:
a. To enable the beeper, use the
Δ
or
∇
key to display OUTSIDE or INSIDE.
b. To disable the beeper, use the
Δ
or
∇
key to display NEVER.
4. Press ENTER. The instrument returns to the normal display state. The instrument
returns to the normal measurement state.
External triggering
The EX TRIG key selects triggering from three external sources: trigger link, digital I/O,
and the TRIG key. When EX TRIG is pressed, the TRIG annunciator lights and dashes are
displayed to indicate the instrument is waiting for an external trigger. From the front panel,
press the TRIG key to trigger a single reading. Pressing the EX TRIG key again toggles
back to continuous triggers.
The Model 2700 uses two lines of the TRIG LINK rear panel connector as External
Trigger (EXT TRIG) input and Voltmeter Complete (VMC) output. The EXT TRIG line
allows the Model 2700 to be triggered by other instruments. The VMC line allows the
Model 2700 to trigger other instruments.
Line 1 is configured as VMC and line 2 as EXT TRIG. The connector pinout is shown in
Figure 8-3 .
Digital I/O
Pin 6 (Ext Trig) of the Digital I/O can also be used as the external trigger input for the
Model 2700. Line 2 of the TRIG LINK is physically connected to pin 6 of the Digital I/O
connector.
The Digital I/O has a hardware interlock line (pin 8) that allows the use of an external
circuit to control input triggers. When that line is left open or pulled high (+5V), input
triggers are enabled. When pulled low to 0V, input triggers are disabled. When disabled,
the Model 2700 will not respond to an input trigger.
Details on the Digital I/O are provided in Section 9 .