How to implement a delay accurately in 44.53ms using PXI6602

[KKLEE]

How can I implement a delay of 44.532 ms accurately using PXI 6602?

[ryan_d]

Hi KKLEE,

I’m assuming you mean for generation? Unfortunately the Start Delay property in the DAQmx Trigger Property Node is not available for the 6602. Therefore, there isn’t any deterministic way for you to delay the counter generation. You can, however, still make an approximate delay by creating a dummy analog input task with a simulated device, and wiring the error lines appropriately. The screen capture below shows how this could be done.

You can create a simulated device in the Measurement & Automation Explorer by right clicking on Devices and Interfaces and then selecting NI-DAQmx Simulated Device from the pop-up window. Choose an M Series device, such as the PCI-6251.

Please post if you have any questions. Have a great day!

Message Edited by ryan_d on 11-28-2007 06:16 PM

Message Edited by ryan_d on 11-28-2007 06:18 PM

Message Edited by ryan_d on 11-28-2007 06:18 PM

[KKLEE]

Hi Ryan,

Thanks for your reply but that is not my scenario.

I'd like to implement kind of delay/wait/sleep but in windows system the resolution is 1ms. My requirement is 1us resolution so I decided to use HW counter/timer to fulfill it.

I was looking at the LabView sample code of "Gen Dig Pulse Train-Finite.vi" but I wonder what is the latency time the "DAQmx Wait Until Done.vi" will inform the system as my requirement is to delay 44.532 ms accurately.

[ryan_d]

Hi KKLEE,

The latency time of the “DAQmx Wait Until Done.vi” will be non-deterministic since it interfaces with Windows. You can, however, obtain 1 us resolution in a deterministic OS with Real-Time.