NI 6361 sampling

[pem]

Hi,

Would like to sample data at 1mHz or more using NI 6361. Since signals are from 7 channels, when collect all 7 data in the same time, the maximun rate is only 240 kHz. Any method can solve this problem? It is not necessary to read all channels in the same time.

Thanks,

Pengm 

[MarcoMauri]

According to the specifications, you should be able to sample your data at 1MHz.

What's limiting you to 240 kHz?

Regards,

Marco

[John_P1]

The 6361 uses a multiplexer to sequentially route each input to a single adc.  The aggregate sample rate is only spec'ed at 1 MHz due to multiplexer switching speed/settling time, so with 7 channels sampled together the rate would max out around 140 kHz according to the spec.  Of course, the ADC can sample at least up to 2 MHz so I'm not surprised you can get a bit faster than 140 kHz--the limiting factor (ignoring settling time concerns) is likely the multiplexer switching speed.

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@pem wrote:

It is not necessary to read all channels in the same time.

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If it's not necessary to read all channels together, then this would solve your issue.  Just read from one channel at a time and you can sample up to 2 MHz.

Best Regards,

[pem]

If it's not necessary to read all channels together, then this would solve your issue.  Just read from one channel at a time and you can sample up to 2 MHz.

Thank you for replies. I do not know how to make a program reading one channel at a time and switch the channel automaticlly. 

Pengm

[Dennis_Knutson]

For loop. Create an array of channels. Inside the loop would be all of the code necessary for reading a singal channel - Create Channel, Timing, Start Task, Read, Stop Task, Clear Task.