I Get "VISA: (Hex 0xBFFF003E) Could not perform operation because of I/O error" On first read of COMS 3 & 4

[9746227715]

I am facing this problem. Anybody found any solution to this?

[h.tang]

Not sure if you are still getting the same problems, but I recently ran into the same error when trying to connect to a serial device through bluetooth and found the following to be helpful:

http://digital.ni.com/public.nsf/allkb/60DDFED7EFEFE7188625705700750821

Basically I placed a VISA set I/O buffer block (search VISA in the functions box) after the VISA serial configuring block and set the mask to 48.  Make sure your expected input and output do not exceed the number you set for buffer size and that solved my problem.

[CaroSalag]

I was facing that issue also, and my solution was plug in the device again (in my case was a pfeiffer pump) and run the VI again... I'm guessing it's because I didn't turn the pump off from labview so the visa didn't close the cycle correctly. I hope that works!

Carolina

[9746227715]

I found a workaround for this issue. It is successful and I tested it well. I used "Clear Errors" after the VISA Read. This clears the error due to the erroneous data coming from serial port of the devices during power On and OFF.  I am attaching a screen shot of the connection (Clear Error) with this, please find that.

 

[niksa]

What was the hardware issue? I'm facing the same problem when my device is connected to hub or when I restart my PC/Laptop.

Works good only after unplugging and replugging USB connection. I'm using Keysight Drivers.

[jcz]

Hi Niksa, in my case the problem lied in additional characters in the comms. Try logging the data on the usb port and see what's goiing on there. 

[EllenRey]

Try to sniff the COM ports with app like serial port monitor. I use this www.eltima.com/products/serial-port-monitor/ 

[MauroMA]

Please could you provide us with a picture of how to install the I / O buffer block. Thanks

[MauroMA]

I found a video on YouTube that helped me solve this problem. Here it is:

https://www.youtube.com/watch?v=6lYMND8b3Qs