NI-DAQ Error -10920 Error from a counter card (samples are lost due to speed limitations of the system)

[Cimteker]

Hi,

There seems to be a few posts related to this error. From what I understand it can be related to:

1. Noise in The Signal

2. Incorrect Board Configuration

3. System Not Fast Enough

I am using PCI-6602 running on Windows XP with Pentium D3.4GHz. I am not 100% sure what NI-DAQ version the system is running but I am assuming it is fairly new as system was integrated this January.

My task is to fix this error, it is appearing in 2 places:

do {

->GPCTR_Watch(CNTVI, ulGpctrNum, ND_ARMED,&ulArmed);

Sleep( 10 );

Wait( 0.01 );

} while ((ulArmed == ND_YES) && !IsAborted() && GetTickCount()-tick < 4000 );

An also here:

->GPCTR_Read_Buffer(CNTVI, ulGpctrNum, ND_BUFFER_START, ulReadOffset, ulNumPtsToRead, ulTimeOut, &ulNumPtsRead, pulBuffer);

With all that knowledge can anybody suggest what I need to do to fix it? If a real cause is not found (known) can implementing retries help?

The system was developed by another developer, as far as I understand the problem is intermittent. If we're suspecitng a noise in the system, how can I eliminate it?

Thank you very much for any insight.

J.

[tnek]

Hi J,

From your post I assume you have looked at the knowledgebase article about error -10920. One way to check for noise is to use an oscilloscope to look at the incoming signal. If the incoming signal does not look like a square wave, you may want to try using shielded cables or physically adjusting the system to reduce environmental noise. If the signal is good, the counter should be able to count each individual pulse and this error is probably caused by another factor. You may want to verify that you are using DMA transfers to ensure that your CPU is free for other tasks. This can be done by following this knowledgebase article. The calls you are making are in traditional NI-DAQ so you may want to use the Set_DAQ_Device_Info() function. Let me know if this helps.

Regards,
Kent
Applications Engineer