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Runtime update of serial visa resource list

Hello,

Is it possible to update the serial visa resource name list in runtime? I think my application should check ports(COM & LPT) from Windows device manager, but I dont know how. The problem is that when a virtual com port is added or removed, I have to restart Labview to update the resource name list. I am using virtual com ports for data acquisition, for example a USB/Serial converterter FT232BM with VCP driver and I'd like to able to connect and disconnect devices while the application is running.

Other than that, FT232BM with VCP driver has been working very well. That was asked here in various posts.

Thanks,

Kari Piipponen
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Hi Kari!

This is a known problem for the NI-VISA driver version 3.3 and earlier. This problem has been fixed in NI-VISA 3.4. I was able to test it on my machine here by using the "Find VISA Resource" function. I ran the program, plugged in and unplugged a USB-GPIB device and was able to refresh the list while the program was running and see the resource appear and disappear. Try this and let me know if you still see the problem. Have a great day!

Chris R.
Applications Engineer
National Instruments

Chris R.
Applications Engineer
National Instruments
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Hi Chris,

thanks for the tip. Actually the newest version, that I found available for download was 3.3.1. But anyway, I updated the VISA and tried an example by Dan Mondrik from thread:
Converting serial port read.vi to VISA, and it worked. The VISA resource list updates when I plug or unplug a usb/serial device.

Thanks again!

Regards,

Kari Piipponen
Applied Electronics Laboratory
Helsinki University of Technology

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