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Section 7: Increasing SMU current sourcing ability Model 2651A High Power System SourceMeter® Instrument User's Manual
-- Set the delay so that the measurement is near the end of the pulse
-- Prepare the reading buffers
smua.nvbuffer1.clear()
smua.nvbuffer1.collecttimestamps
= 1
smua.nvbuffer1.collectsourcevalues
= 1
smua.nvbuffer1.fillmode
= smua.FILL_ONCE
smua.nvbuffer2.clear()
smua.nvbuffer2.collecttimestamps
= 1
smua.nvbuffer2.collectsourcevalues
= 1
smua.nvbuffer2.fillmode
= smua.FILL_ONCE
-- Configure TSP-Link Trigger 1
tsplink.trigger[1].clear()
tsplink.trigger[1].mode
= tsplink.TRIG_FALLING
tsplink.trigger[1].stimulus
= trigger.timer[1].EVENT_ID
-- TSP-Link Trigger 1 signals 2651A #2 to pulse
-- Timer 1 controls the pulse period by triggering the pulse to begin
trigger.timer[1].count = dsteps - 1
trigger.timer[1].delay = pulsePeriod
trigger.timer[1].passthrough = true
trigger.timer[1].stimulus = smua.trigger.ARMED_EVENT_ID
trigger.timer[1].clear()
-- Timer 2 controls the pulse width
trigger.timer[2].count = 1
trigger.timer[2].delay = pulseWidth - 3e-6
trigger.timer[2].passthrough = false
trigger.timer[2].stimulus = smua.trigger.SOURCE_COMPLETE_EVENT_ID
trigger.timer[2].clear()
-- Configure SMU Trigger Model for Sweep
-- Each unit will source half the current, so divide the start
-- and stop values by 2
smua.trigger.source.lineari(dstart / 2, dstop / 2, dsteps)
smua.trigger.source.limitv
= pulseLimit - (pulseLimit * 0.1)
-- Again, keep the limit SMU #1 lower than the limit of SMU #2
-- to prevent parallel V-sources
smua.trigger.measure.iv(smua.nvbuffer1, smua.nvbuffer2)
smua.trigger.measure.action
= smua.ENABLE
-- Return to the bias level at the end of the pulse/sweep
smua.trigger.endpulse.action = smua.SOURCE_IDLE
smua.trigger.endsweep.action = smua.SOURCE_IDLE
smua.trigger.count
= dsteps
smua.trigger.arm.stimulus
= 0
smua.trigger.source.stimulus = trigger.timer[1].EVENT_ID
smua.trigger.measure.stimulus = 0
smua.trigger.endpulse.stimulus = trigger.timer[2].EVENT_ID
smua.trigger.source.action
= smua.ENABLE
7-12
2651A-900-01 Rev. A / March 2011