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Problem with reading out dada from the photodetector memeories

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Hello guys,


I am new in  programming ( couple of months) in the LabView and currently trying to control a photodetector interface using the LabView.

For initializing the detector controller, the program is up to now working properly and there is no problem with concerning the initial steps to start  a measurement.

However, when I start the mean program to take measurements, there is always problems with the reading out the data from the memories of the detector. When I execute the program. the controller receives the all the commands I send to controller and all the scanned information are stored in the designated memories of the detector. But Visa read can not read out the all the information stored in the memories. there are always some counts missing from the measured data. I tried to extended the timeout value of the Visa read. it seems it does not help that much as the problems occurs randomly which means Visa read sometime can read out the all data points and some time just some data points.


It would be highly appreciated if someone could give me any suggestions or feedback.


I also attached the Vi and measured data that I get out of the detector.




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Message 1 of 5

I've had similar problems reading all of the data using timeout, and have paired the read method with the "Bytes at "Port" method for better results.  This way you always read however many bytes are there at the port.  Then I just store that data in a shift register and parse out the data I'm looking for (could be with STX, ETX termination characters for example).



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Message 2 of 5

Thanks for your reply, as far I understood you had communicated with the serials port. It seems the trick you applied does not work with my case as I communicate with the instruments using the GPIB connection. But I will try to one more as you suggested.


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Message 3 of 5
Accepted by topic author Avral

The Problem is solved, I used the case structure to check the returned bytes until I fully read out the requested bytes from the instrument.

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Message 4 of 5

hi sir, i want to read the intesnity from photo detector.Can you share the VI

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Message 5 of 5