Section 3: Functions and features
Model 2651A High Power System SourceMeter® Instrument Reference Manual
3-56
2651A-901-01 Rev. A / March 2011
-- Configure digital I/O lines 2 and 14 for input trigger detection
-- and output trigger generation, respectively.
digio.trigger[2].mode = digio.TRIG_RISINGA
digio.trigger[2].clear()
digio.trigger[14].mode = digio.TRIG_FALLING
digio.trigger[14].pulsewidth = 0.0001
-- Wait 15 seconds for a trigger event to occur on digital I/O line 2
trigInput = digio.trigger[2].wait(15)
-- If a trigger event occurs on digital I/O line 2, assert an output
-- trigger on digital I/O line 14. If a trigger event does
-- not occur, then turn off the output of smua and issue a message
-- on the front panel display.
if trigInput == true then
digio.trigger[14].assert()
else
smua.source.output = smua.OUTPUT_OFF
display.screen = display.USER
display.clear()
display.setcursor(1,
1)
display.settext("No trigger received. Test aborted.")
exit()
end
Hardware trigger modes
Different hardware trigger modes can be used for digital I/O and TSP-Link synchronization. Use
hardware triggers to integrate Keithley instruments and non-Keithley instruments in a test system.
The Model 2651A supports 14 digital I/O lines and three TSP-Link
®
synchronization lines that can be
used for input or output triggering. For additional information about the hardware trigger modes, see
(on page 5-1).
NOTE
For direct control of the line state, use the bypass trigger mode.
Falling edge trigger mode
The falling edge trigger mode generates low pulses and detects all falling edges. The figure titled
"Falling edge input trigger" shows the characteristics of the falling edge input trigger; the figure titled
"Falling edge output trigger" shows the falling edge output trigger.
Input characteristics:
•
Detects all falling edges as input triggers.
