why is buffered event counting cumulative

[jamie boyd]

I'm trying to do buffered event counting using general purpose counters on an e-series board. It doesn't work quite as advertised. Each point in the buffer is supposed to contain the count of source events that occurred between successive pulses of the gate, according to the Nidaq function reference manual. I find, however, that every point contains the cumulative number of events, so the data are monotonically increasing. Is there a setting somewhere to change this behavior, or is there an error somewhere - either in the documentation, or in the code?

This was with NI boards 6711 and a 6035 in a G4 running OS 9.

[gus]

Where in the documentation does it suggest that buffered event counting is not cumulative? This would be an error in the documentation. Buffered event counting is cumulative. If you would like to have non-cumulative behavior, you would want to program the counter for buffered period measurement.

Hope this helps!
gus....

[jamie boyd]

Gus said:

"Where in the documentation does it suggest that buffered event counting is not cumulative?"

page 8-51, NI-DAQ software reference for Macintosh. The example shows the buffer containing values of 4, 2, and 5, corresponding to the number of events between consecutive transitions of the gate, not the cumulative total of events since counting started.

I have just checked to ensure that buffered period measurement is not cumulative, and it is not (which is good).

Thanks for the tip.

jamie