LabVIEW
Trouble with receiving data from a Zebra Miniscanner in LabVIEW.
Solved!
Yes, as you've found NI I/O Trace only works with NI software unfortunately. There are other serial port monitors out there, but if you're sending data to Termite successfully then it's not a serial port issue.
Can you use Save for Previous to an earlier version of LabVIEW? I don't have 2021 installed.
Also, the "NI MAX Query" function only works with SCPI instruments. I very much doubt that your scanner is SCPI compatible so I wouldn't even try those commands.
It would also be helpful to post some more info about your communication protocol, perhaps from a manual.
It sounds right now though that your scanner sends a burst of data when you push the Scan button and it reads something. Hopefully it has a termination character, so you can just set up LabVIEW to use that termchar. Do a VISA Read with a fairly short timeout (0.25 or 0.5 seconds). If nothing came in (i.e., you get a timeout error), clear the error and try to read again. If you get something, then you know the scanner sent something.
The only reason not to make your timeout super long is that, once called, VISA Read will block until you timeout, read the requested number of bytes, or receive a termchar. If you set the timeout to 5 minutes and decided to stop listening on that port, you'd have to wait 5 minutes before VISA Read returns.
(Note: you may be able to call VISA Close in parallel to "abort" the read. I haven't done that before but it'd be easier to just call Read in a loop.)
If LabVIEW can't read it you may not have NI VISA installed properly. Anything Termite can do, LabVIEW can do.
Let me get this straight though- you open a terminal in Termite, then when you scan a barcode, some data shows up. Right? If so, what you have in LV should work. If you're not getting anything at all then you either have a VISA driver problem or an issue with your code.
What exactly does your code do or not do? If it's getting a timeout error, then your While loop is reporting that there ARE more than zero bytes at the port. That means it's getting *something* in the buffer. When you try to read that many bytes, it should return them immediately.
BTW, one small issue is that, by default, VISA Open defaults to "True" for Termchar. Try setting that to False. Also, you basically never need to use Bytes at Port.
Give this a shot. Run it and click the buttons to scan stuff. It should display something.
Then that indeed is very weird. Sounds like whatever the driver is for your serial device isn't VISA compatible. Could you try to update the drivers there? I've had very odd errors with older Silicon Labs chips (IIRC) that would work with (again IIRC) Teraterm but not LabVIEW or Termite. I could be remembering wrong though, and I don't recall the fix either. See if you can find a USB VID/PID in Device Manager, and it'll tell you what the USB to Serial device is (assuming you're connecting via USB).
Still though- earlier you said you were getting timeout errors. Based on the code you showed, you'd only ever get a timeout error if the While loop exited, which only happened if there was an error (which you wouldn't see with just a Bytes at Port node) or the Bytes at Port node returned a number other than 0. What was it returning? And are you sure it wasn't just returning non-printable characters or something?
If the transmission happened to include erroneous termchars in it then your string indicator wouldn't show any data since the default termchar is a non-printing character.
