Model 2651A High Power System SourceMeter® Instrument Reference Manual Section 9: Frequently asked questions (FAQs)
2651A-901-01 Rev. A / March 2011
9-3
Figure 110: Triggering a scanner
Scanner
Model 2651A
DIGITAL I/O
DIGITAL I/O
Line 1
Line 2
Trigger in
Trigger out
• • •
Legend:
= Trigger object
= External input trigger
= External output trigger
Programming triggering
The programming example below illustrates how to set up triggering. The example sets the output
pulse width on line 1, then programs both lines 1 and 2 for falling edge triggers. Digital I/O line 1
trigger asserts and then line 2 waits for the input trigger up to the timeout period specified.
-- Set line 1 pulse width to 10 us.
digio.trigger[1].pulsewidth = 10e-6
-- Set line 1 mode to falling edge.
digio.trigger[1].mode = digio.TRIG_FALLING
-- Set line 2 mode to falling edge.
digio.trigger[2].mode = digio.TRIG_FALLING
-- Assert trigger on line 1
digio.trigger[1].assert()
-- When complete Wait for trigger on line 2.
digio.trigger[2].wait(timeout)
More information on triggering
For additional information, see
(on page 3-32).
How do I generate a service request?
NOTE
For detailed information on this topic, see the
(on page E-1) section of this manual.
Setting up a service request
The exact programming steps necessary to generate a GPIB service request (SRQ) will vary
somewhat depending on the event(s) intended to generate the SRQ. In general, the steps used will
be as follows:
1. Clear all status registers to prevent anomalous events from generating an SRQ.
2. Set bits in the appropriate operation: questionable, measurement enable, or transition register(s).
3. Set the proper summary bit in the service request enable register. At least one bit in this register
must always be set, but the exact bit(s) to be set will depend on the desired SRQ event(s).
