synchronize counter and analog inputs on PXI

[DavidT]

Hi,
I have a setup consisting of a PXI-6629 M-Series card and PXI-6624 counter card. I want to continously read 13 analog inputs and synchronize them with 3 quadrature counter inputs on the counter card. What is the best or easiest way to synchronise my signals and ensure that they are reading at the same time? Preferrably, I would like to do single point aquisition at approximately 3khz. I will be doing the DAQ on an RT system.

Thanks,
David

Message Edited by DavidT on 06-19-2008 01:55 PM

[mallorim]

Hi David,

In order to synchornize the M-series Acquisition and the Counter Input tasks you will have to share a sample clock between the tasks and ensure that the Counter task is started first. This can be seen in the VI I am attaching below. The Counter Task's Sample Clock is pointed at the AI Sample Clock, and through routing the error cluster, I have enforced order of execution. The reason the Counter task has to start first is because it needs to be ready to begin when the AI task starts generating the sample clock. While you can use one analog input task for multiple channels by having PXI2Slot2/ai0:3, you will need to add a new Counter Input task for each counter you use. I hope this explanation helps.

Regards, Mallori M.