Operator`s manual

Signametrics 50
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4.14.3.2 Multiple Trigger Capture Operation
In response to the DMMSetBuffTrigRead (nDmm, iSettle, iSamples, iEdge) command, the DMM waits
for hardware trigger edge of iEdge polarity to make measurements. For each trigger input it makes a
measurement(s), storing the results in its on-board buffer. For each measurement is made up of iSettle + 1
samples, saving only the last sample. A total of iSamples trigger input pulses are required to complete the
capture process, and iSamples are saved to the buffer. With the Read Interval set to 0, the total time per
measurement is (iSettle + 1) * Aperture plus the time it takes to save the data to the buffer. The last is
equal to 130µ for Aperture times greater than 625µs, and 117µs for other apertures. iSettle may be set to a
value from 0 to 250. The total number of measurements, iSamples, must be between 1 and 80 for
Aperture greater than 625µs, 120 otherwise. Setting the Read Interval can help with fine tuning of the
sampling timing. Use the DMMReady() function to monitor completion. Aperture time must not exceed
160ms.
i = DMMSetBuffTrigRead(0, 2, 50, LEADING) ‘two settling readings, 50 samples and positive Edge.
While DMMReady (0) = No ‘ wait for completion
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For i = 0 To Samp - 1 'Read measurements from buffer.
DMMReadBuffer 0, rd(i)
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4.14.3.3 Burst Capture to Buffer
The DMMBurstBuffRead function is similar to the soft Trigger function, DMMTrigger. In response to
the DMMBurstBuffRead (nDmm, iSettle, iSamples) command, the DMM captures iSamples and stores
them to the on-board buffer. For each measurement saved it takes iSettle + 1 samples, saving the last one.
With the Read Interval set to 0, the total time per measurement is (iSettle + 1) * Aperture time plus the
time it takes to save the data to the buffer. The last is equal to 130µ for Aperture times greater than 625µs,
and 117µs for other apertures. iSettle may be set to a value of 0 to 250. The total number of
measurements, iSamples, must be between 1 and 80 for Aperture greater than 625µs, 120 otherwise.
Setting the Read Interval can help with fine tuning of the sampling timing. Use the DMMReady()
function to monitor completion. Aperture time must not exceed 160ms.
i = DMMBurstBuffRead(0, 2, 50) ‘two settling readings, 50 samples and positive Edge.
While DMMReady (0) = No ‘ wait for completion of capture process
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For i = 0 To 50 - 1 'Read measurements from on-board buffer.
DMMReadBuffer 0, rd(i)
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4.14.3.4 Triggered Burst Capture
This function is similar to the Burst Read operation above. In response to the DMMSetTrigRead
(nDmm, iSettle, iSamples, iEdge) command, the DMM enters a tight loop, where it responds to a trigger
edge. On each of these edges triggers the DMM to capture and send back a measurement. The total of
trigger edges and measurement being equal to iSamples. For each hardware trigger edge, the DMM takes
iSettle + 1 measurements, sending the last one. The S/W must keep up and read those samples as they
come. iSettle may be set to a value from 0 to 250. The total number of measurements, iSamples, must be
between 1 and 30,000. Setting the Read Interval can help with defining the sampling timing. Use the
DMMReady() function to monitor completion. Aperture time must not exceed 160ms. The amount of
time it takes the DMM to transmit the data back depends on the selected Aperture. It is about 132µ for
Aperture times greater than 625µs, and 88µs for other apertures.
i = DMMSetTrigRead(0, 2, 500, LEADING) ‘Two setteling readings per sample, 500 measurements
For i = 0 To 500 – 1 'Tight read loop, need to get them as fast as they come. Read 500