PCIe-6321 delay sampling

[ndaigle]

I have a resonant mirror which scans a line across the field of view of my microscope over 62.5 microseconds. I need to sample my detector over the field of view 250 times to create 250 pixels. This means ideally I would sample with my DAQ card every 0.250 microseconds.

I would like to take analog input data over 3 channels. However, I have a PCIe-6321 with a sampling rate of 250 kS/s, which reduces to 83.3 kS/s acrossn each of the 3 individual channels. This means the fastest I can take samples is every 12 microseconds, significantly slower than I need. For every pass of the resonant mirror, I can only sample the field of view 5 times instead of the necessary 250 times. Therefore, I would have to scan one line of my field of view 50 times to acquire all 250 pixels.

Is there a way I can control the PCIe sampling to ensure that I'm sampling new pixels every subsequent line scan? My initial idea was to somehow delay subsequent read-ins by a set amount (0.250 microseconds) to shift the pixel I'm detecting over by one each time, and repeat this 50 times to scan each line fully. Is this possible?

Thanks for any help!

[ZYOng]

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@ndaigle wrote:

Is there a way I can control the PCIe sampling to ensure that I'm sampling new pixels every subsequent line scan? My initial idea was to somehow delay subsequent read-ins by a set amount (0.250 microseconds) to shift the pixel I'm detecting over by one each time, and repeat this 50 times to scan each line fully. Is this possible?

No it is impossible.

250kS/s is the hardware limitation restricted by the settling time of the ADC and circuitry to capture the voltage correctly. Even if the driver allows you to read faster than this, the data return is inaccurate.

You should get another DAQ that meets your 4MS/s sample rate requirement.