Trigger Delay with 6652 & 4071

[Wortel]

Hi,

Not sure if this should go in the PXI section or the LabVIEW one....

I have a PXI-1042 Chassis with a PXI-6652 Timing module (in slot 2) and 4*PXI-4071 DMM cards.

I am trying to synchronise the data capture from the DMMs using the star trigger from the timing module and I have a had some success, however I think it should work a little better but I cannot seem to find out how.

The main issue I am having is that the signals are still out of sync by about 20 to 30 samples at a sample rate of 10KS/s, I know this isn't much but it may have an effect on the final calculations from the data captured.

I am using the Route to all PXI_STAR.vi from the examples to send the trigger and the cards are set up to wait for the star trigger to start recording. Is there anything else I need to do to tweak out the last few nanoseconds from the system, maybe a setting in MAX or something?

At the moment I am initialising the DMM cards seperately (so I have 4 identical lines in the code), is there a way to do this just using the one niDMM Initialize.vi, or do I have to use one for each card?

Thanks in advance for any help,

Darren.

[ninlmartijn]

Dear Darren,

Thank you for your post on our website.

Are the DMM's always a same amount of samples out of sync? If they are; a delay in your triggering would be a option. This terminal can be found on the config trigger vi. Please notice that you are introducing different measurement times between the DMM's; this can influence the RSM value the DMM has measured in that measurement cycle.

It is not possible to initialize multiple DMM's at the same time.

If ther are any questions, please let me know,

Best Regards,

Martijn S

NI NL