Series 3700A System Switch/Multimeter User's Manual
Section 4: Applications
digio.writebit(1, 1)
digio.writebit(2, 1)
digio.writebit(3, 1)
digio.writebit(4, 1)
digio.writebit(10, 1)
Define the Series 3700 digital I/O
as inputs, then redefined by
trigger model triggers.
scan.trigger.arm.clear()
scan.trigger.arm.stimulus = 0
scan.trigger.channel.clear()
scan.trigger.channel.stimulus = 0
Set the trigger event for each
trigger layer.
Set the arm and channel trigger
events to pass through
immediately.
scan.bypass = scan.ON
digio.trigger[10].mode = digio.TRIG_RISING
Define the Series 3700 digital I/O
input trigger.
Set scan bypass on, which does
not gate the channel trigger
layer.
scan.execute
is the first
trigger, closing the first channel
in the channel list.
Detects the rising edge input
triggers and automatically
latches and drives the trigger line
low. Asserts a TTL-low pulse as
an output trigger.
Note that you must use digital I/O
10 through 14 with legacy
DMMs. The pull-up of the Series
3700 is too strong on lines 1 to 9.
scan.trigger.sequence.stimulus =
scan.trigger.EVENT_CHANNEL_READY
Allows the trigger model to drop
to next layer immediately.
scan.trigger.measure.stimulus = digio.trigger[10].EVENT_ID
Receives VMC signal from an
external DMM. The measure
stimulus gates every DMM
reading. Every DMM reading is
triggered by external digital I/O.
digio.trigger[2].mode = digio.TRIG_FALLING
digio.trigger[2].pulsewidth = 5e-6
Define the digital I/O output
trigger. Send a trigger to an
external DMM.
digio.trigger[3].stimulus =
scan.trigger.EVENT_MEASURE_COMP
digio.trigger[3].mode = digio.TRIG_FALLING
digio.trigger[3].pulsewidth = 5e-6
Define the Series 3700 digital I/O
output 3 trigger.
digio.trigger[4].stimulus=
scan.trigger.EVENT_CHANNEL_READY
digio.trigger[4].mode = digio.TRIG_FALLING
digio.trigger[4].pulsewidth = 5e-6
Define the Series 3700 digital I/O
output 4 trigger.
dmm_buffer_size = (scan.measurecount * scan.scancount *
scan.stepcount)
buf_size_max = dmm_buffer_size
buf = dmm.makebuffer(buf_size_max)
buf.clear()
buf.appendmode=1
Initialize the buffers to a variable
buffer size.
3700AS-900-01 Rev. A / July 2011
4-23