overheat

[TimRessel]

Hi,

We are using a PCI-6733 to generate 60Hz sinewaves. In the afternoon after running all morning the card starts to drop sinewave cycles randomly. Turning the PC off for 30 minutes seems to fix the problem. The PC is an HP with not a lot of cooling. Has anyone seen this? Is it a PC issue or a DAQ issue?

Thanks! 

[griffindore]

Hi Tim,

Do you have any idea about how high the temperature is ramping up in your system? The 6733 has an Operating Temperature specified from 0 to 50 degrees C. Do you have any system monitoring tools that give you temperature feedback on your system? This KB describes how to read the temperature sensor on your DAQmx device. It would be useful to know what the temperature is when you start receiving these problems.

Is there any ventilation around your computer? If it's in a cabinet, you could try moving it out and maybe opening up the case to see if that helps. Do you see any other system problems other than the card's output? Could you provide some type of screenshot that shows what you mean by "the card starts to drop sinewave cycles randomly?" I hope this helps!

[TimRessel]

Hi Mike,

Thanks for the response. Our card is reading 45C when failing.

Another bit of info: When the failure occurs we kill our application and fire up the NI test panel for the card, and that works just fine. Our current theory is that we are interfacing to the NI card in our code in an inefficient manner that causes the missed cycles. This would mean there is some timing thing on the motherboard that is on the edge and is caused to fail from extra heat, but doesn't affect the test panel because it interfaces to the card better.

Does any of this sound plausible?

--Tim Ressel, Veris Industries 

[griffindore]

The 45C temperature is within the operating conditions of the card, so the card should be fine (although you are approaching that limit). Do you have any other system monitoring tools to see what the temperature is on your processor and mobo?

I still don't think I clearly understand what you mean by dropping sinewaves randomly. Are you doing continuous generation or N Samples? If it's continuous, the hardware timing is done on the 6733. The system timing will only affect things when you are not performing continuous generation (could affect timing in between one set of N Samples and the next set of N Samples). When you're using the MAX test panel, are you using continuous mode? Could you give some details about your application (possibly screenshots and the development environment)?