Instrument Control (GPIB, Serial, VISA, IVI)
USB to 232 serial communication issues Mass Flow Controller
Solved!
I have been having issues troubleshooting serial communication from a MKS mass flow controller, MKS647C, which had been using a software handshake to communicate through a serial to USB driver. There are lots of unknowns for me here, like why is the prolific driver randomly appearing with "THIS IS NOT PROLIFIC PL2302" when yesterday it had been appearing fine. The issues with this setup occurred to the best of my knowledge when there were updates on the computer six months ago and I had to reload the driver setup. The instrument says its making use of XON/XOFF which i took from the manual to be a software handshake. Is there more settings I need to configure in device manager? I have tried reinstalling serial drivers but no luck. Any guidance on how to go about troubleshooting this would be very helpful. I have never encountered the Ni-Max error that it has found the correct resource but cannot open a VISA session, and I looked through this forum for similar errors but found none of their steps to be applicable.
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@Andy_7 wrote:
What ended up working for me was: Replacing the USB to serial cable. Turns out it was a very old prolific USB to serial, which was part of the reason it would show up strangely in Device Manager. Took me a while to get there because I thought the issue would be in the driver or LabVIEW layers. Lesson learned to not take old adapters for granted!
Anecdotally, I hear a lot of complaints with Prolific based USB-RS232 adapters. However, I have had a lot of success with a specific prolific adapter (I am unable to find the model number at the moment). Most people seem to really like FTDI adapters. Personally, I have had the most success with adapters from StarTech, such as ICUSB2324i which are based on a TI chip. Granted, I get the industrial-grade adapters, so they are pricey.
