multitasking with multiple 6255 card

[gangmu1]

Dear collegues

Four 6255 cards are plugged into the 1078 chassis. Attempting to process the channels from the first slot of each card at the same time, 1-5 times, and trying it at NImax (Measurement and automaton exploer) will fail and error 201426 will occur. I would like to know if this is a hardware limitation or a configuration error.

Thank you in advance.

Truly

gangmu1

[gangmu1]

Four 6255 cards are plugged into the 1078 chassis. Attempting to process the channels from the first slot of each card at the same time, 1-5 times, and trying it at NImax (Measurement and automaton exploer) will fail and error 201426 will occur. I would like to know if this is a hardware limitation or a configuration error.

[crossrulz]

This is a limitation on the M series of DAQ boards.  You cannot have a single task handle multiple cards.  You have to have a separate task for each card.  But you can share the sample clock by routing the the sample clock of one board through the PXI backplane and have the other cards use that clock.  This is done with the "Source" input on the DAQmx Timing VI.

[gangmu1]

Thank you very much.
I am programming with C #, but can you explain it a bit more specifically? .

[crossrulz · Accepted solution]

It looks like you need to use the DAQmxCfgSampClkTiming function.  One of the parameters is "source".  If you dig through examples, I am sure you will find the exact information you are looking for.  On my machine, the example you are most likely interested in is located at C:\Users\Public\Documents\National Instruments\NI-DAQ\Examples\DAQmx ANSI C\Analog In\Measure Voltage\Acq-Ext Clk