Delay between labview and hp 83620A microwave synthesized Sweeper

Hello world

I'm using microwave synthesized Sweeper hp 83620 has to sweep the microwave from one frequency to another.  I control the instrument via GPIB-USB-HS.  I use the device provided by Labview driver. http://sine.NI.com/apps/UTF8/niid_web_display.model_page?p_model_id=782

My program tells the instrument, the frequency of start and stop as well as the size of frequency step and downtime.  But at some point of time, I want to know the instantaneous frequency that produces the instrument and save it as data, so I built in a virtual meter within the program.  But it seems to me that when I hit the run button, it takes time before the instrument scan.  This makes the frequency meter reading ahead and save the wrong values.

So nobody knows exactly how long the delay is. It seems that this period is about 1 second, but I need a more precise value have a reliable data acquisition.  I would really appreciate an entry and a suggestion for improving the program.

Thank you.

P.S. I have included the image VI below for convenience.

Tom,

When you work with LabVIEW, it is important that you understand its paradigm of data flow. This means not only no function, the Subvi or the loop runs until all nodes input receive data. And no loop will return the results to the output until the loop is completed. So in your case, we just need to understand what the function is in your top string actually starts the scan. If it's the call after the outbreak of arms vi branch simply error on the wire from the loop for. (you can't even wire to something else and please note I said branch it) due to the assistant of the instrument you cannot expect perfect results. If you have not run it with execution highlighting turned on (bulb on the block diagram toolbar) Please try it.

Tags: NI Hardware

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