How big is PXIe-4154 Measurement Memory/Buffer?

[juswanto]

I am planning to use PXIe-4154 to make multiple measurement, V and I, subsequently using hardware trigger. To minimize software time, I would store each measurement in its memory/buffer, and later after all measurements are taken, do measurements fetch with one command like 

niDCPower_FetchMultiple().

[Chris-G]

Hi juswanto,

The PXIe-4154 (and most other NI SMUs) have a DMA line that allows the device to create a buffer in the host computer's memory. The size of this buffer is 1 second worth of data at the device's maximum sampling rate. For the 4154, this means that the buffer size is 200k samples. When you fetch the data using this function you will be fetching from this buffer.

The device itself has a small hardware buffer on it, but the DMA line allows the measurement data to transfer to the host memory much faster than that data fills the hardware buffer. So the effective size of the buffer is 200k samples thanks to the DMA and host memory.

Hopefully this helps,

Chris G