Problems with arinc-429 and DAQ.

[Murillo]

Hi!,
In a Pxi-1006 chassis we have configured Pxi-6031e cards, from NI, and also an Arinc429 card (avionica bus) from Pickering. We are making tests in which a process of analogical acquisition (double buffer as in NIDAQ documentation)and a process of Arinc429 communication take part simultaneously. Both processes work correctly if they are called in separate tests. Nevertheless, when they take part in a same test, the operative system (loaded in a PXI-8176 card) blocks completely (not even responds to Ctrl+Alt+Supr), so we have to make a reset . It seems to be mutual incompatibility problems . The blockade does not take place when minimum benefits are demanded (acquisition rates of the order of 10ms for a minimum number of channels and
occupation rates of 30% of the Arinc429 channel). Any information on this subject? Any similar case? Thanks all.

[rgharrison]

Hi Munrillo,

Take a look at the following KB: http://digital.ni.com/public.nsf/websearch/8009C7AF8F37187186256BCE007E0F0A?OpenDocument

It describes a situation in which the controller freezes.

In terms of NI-DAQ driver calls blocking the system, this could happen if there is no delay in the acquisition routine. You must use a system wait or delay in their code so that the double buffering loop isn't always calling the driver continuously and blocking the system from doing other things. Let me know if this isn't clear. Any other specific information might help me determine suggestions. Hope that helps.

Ron

[Murillo]

First of all, thanks for your answer, Ron.
You are right, my acquisition routine doesn't include a system wait. It's performed by a "while" loop where the first call is "DAQ_DB_HalfReady", without any delay inside the loop. I'm going to try with the event message functions ("Config_DAQ_Event_Message"). If you are interested, I'll let you know the conclusions.
Thanks again.