@GerdW wrote:
Hi engraqeel,
@engraqeel wrote:
I am planning to purchase NI-9775 with cDAQ 9171, and I want to use only one channel for continuous data acquisition mode. Will I get the 20 MS/s rate for single channel? If yes what are the other limitations of NI-9775 with cDAQ 9171.
- The cDAQ9171 is offered with a USB2 interface, this means the communication is limited to 480Mbit/s (raw!). This typically results in up to 40MB/s transfer speeds (due to data encoding and transfer protocols)…
- You want to read 20MS/s: with 16bit data this will need 40MB/s, with 32bit data you request for 80MB/s.
For me this reads like a typical conflict between requirements and hardware capabilities…
Generic suggestion:
When you want to handle high-speed data acquisitions you should use suitable hardware!
Asking for (old) USB2 devices is asking for trouble: look for other better options…
Surprisingly the USB 6366 can push 32MB/s continuously which is the practical speed limit for USB2 (theoretical is 64MB/s). If programmed correctly I have had them run continuously for weeks at a time at that rate.
