PXI 6602 pulsewidth timing?

[Beck45]

Using the PXI-6602 with LabView 8.5, is there anyway to get the time of when a pulse occurs?  Continuous pulsewidth reading is good, but just need time info also.  Essentially we need the function of cont. digital read, which we do on the PXI 6123, but we might run out of channels on that. 

Thanks.

[tnek]

Hi Beck,

If you were looking for precise relative timing between pulses, you can use the period (if you want times between rising edges) or semiperiod (time between a rising and falling edge, etc) counter input measurements. You can then add the periods or semiperiods together to get the total time from the first edge. You can also use the Get Date/Time In Seconds function in LabVIEW to generate a timestamp if you wanted to get an absolute reference

Regards,

Kent

Applications Engineer

[Beck45]

Thanks for you reply.  I'd like to try the timestamps.  We just need to write the time a pulse arrives and its width to a tdms file.  What would be the best way to do this within say a Pulsewidth VI that uses implicit timing?  How can I output the Get Date/Time result to the file?  

[tnek]

Hi Beck,

I would still recommend a period measurement if you are looking for times between rising edges. See the screenshot below from the NI-DAQmx Help which shoes the differences between these counter measurements.

 

You can then add the period between rising edges from each subsequent an initial timestamp to get the timestamp of when that pulse occurred. This can then be complied into an array which can be written to a file.

Regards,
Kent
Applications Engineer NIC

Message Edited by tnek on 12-11-2008 04:56 PM