Ni 9263 sometimes outputs 16.6mV independent of the specified voltage and unrelated outputs for low timing rates around 10 kHz

[ouz]

Hi,

I have a problem about Ni 9263. I am applying a continuous analog output(dc voltage) from Ni 9263 and measuring that using Agilent 34401a via GPIB.  Sometimes, Ni 9263 couldn’t write the specified value and I read 16.6mV from Ni 9263 whatever the specified outputs are (I checked ithat value with multimeter at the output of Ni 9263). Also, if I decrease timing rate around 10 kHz, Ni9263 results in unrelated output voltages. Is there limitation for NI 9263 timing rate (other than max update rate is 100kS/s) or is there something that I am missing?

I attached the vi which is very simple. Also, I tried same thing with Ni9264 and same problem which makes me suspicious about my vi.

Thanks for the response in advance.

Regards,

Ouz

NSC

[ouz]

Is there anyone who has an idea or suggestion about this problem?

Thanks,

Ouz

NSC Intern

[TSJim]

It is possible that there is a hardware problem - the AO can supply 1mA so it has to drive a high impedance device - if only the DMM is connected this shouldn't be a problem but if another device is switching in and out it may keep the output near ground when it's switched in.

Did you try using MAX to set a fixed output voltage and does that always work?

Thanks,
Jim

[ouz · Accepted solution]

Hi Jim,

Thanks for your response. I have connected the DMM directly to the Ni9263 and I have also checked with MAX and it works as expected.

Finally, I solved the problem thanks to one of Ni forum post in 2007 http://forums.ni.com/t5/LabVIEW/Analog-Output-Buffer-Size/td-p/612858 . As explained here, we couldn't use Timing for DC constant value.  Maybe, this will be helpful for others.

Thanks,

Ouz