How do I calculate the max latency of a PXI 8135 (controller) to PXI 6528 (DIO) output?

[dan_f]

We are using a PXIe- 8135 Controller and a PXI-6528 DIO module in a PXIe-1082 chassis.  We are sending DIO input and output commands using Powershell in Windows 7 on the controller.  Due to tight requirements I need to know what is the max latency from when the Powershell command is issued to when the read input or write output command will take place in the DIO I/Os.

If this should be in a different Community Board Location please let me know.

Thanks for the help in advance,

Dan_F

[chipsahoying]

Hello dan_f,

As the latency of Powershell and Windows are not tested, it is hard to determine the latency of your setup.  The latency from the PXIe-8135 to the PXI-6528 should be in the realm of nanoseconds.  The PXI-6528 does have a couple of latency numbers that can be found within the user manual on Page 24, and they are as follows:

Minimum pulse-width for change detection - 150 µs

Propagation delay - 65 µs, typical

You may be able to do some testing to ballpark the latency of the controller OS/software side of the input/output commands, but depending on how critical this latency is to your measurements, you may want to look into using a real-time OS instead.