Warning #10092 upon PCI6052E setup

[josswern]

recently I encounter problems when using my cvi app with PCI6052E cards using the following cvi code:

Err = DAQ_Rate (MaxRate, 0, &Timebase, &Interval);
// error processing goes here
Err = DAQ_Rate (SampRate, 0, &ScanTimebase, &ScanInterval);
// error processing goes here
Err = SCAN_Start (Board, buffer, Nch * Nsamp, Timebase, Interval, ScanTimebase,
ScanInterval);
// error processing goes here

basically, this determines the parameters for the scan setup of my device based on the desired sample-rate (which is of course checked to be viable for the instrument) - this has been working well with any E series board so long - only with PCI6052E, scan_start
returns error
code 10052 even upon requesting moderate sample rates (~ 40 KHz), which is meant to be a 'warning'.
if I just ignore it and proceed, the data acquisition seems to work properly, but I'm not sure if this is ok.
anyone knows what's going on here ?

[Ben]

Try changing your "Scan Interval", see below.

Warning 10092 occurred at an unidentified location.

Possible reasons:

NI-DAQ LV: Some devices require a time gap between the last sample in a scan and the start of the next scan. The scan interval you have specified does not provide a large enough gap for the board. See your documentation for an explanation.

Ben

[josswern]

Hmm,
thanks for reply - but isn't a scan interval returned
by DAQ_Rate supposed to be valid for the requested device ?

[Ben]

Sorry about the delay in responding. I only answer questions in my spare time.

Please very what I am about to say.

NI-DAQ will guess at a scan interval when you specify a sample rate. The scan interval refers to the time period between A/D operations on the board. Many non-simultaneous sampling boards will use a mux to sequence through all of the configured input channels. The time interval determines the time between when the A/D triggers for channel 0 and triggers for channel 1, etc. If you specify a high number of bits of resolution, the A/D converter can take longer to settle in on the sample.

I can not tell you precisely why NI-DAQ is not filling a good interval based on your sample rate. I have seen whre the NI-DAQ supplied interval ha
d to be changed to minimize "Cross Talk" between adjacent channels.

Ben