Keithley 6485 - RS232 Serial Port COM1 - VISA Not Communicating

[AnonymousChemist]

Hi There,

We have an old Keithley 6485 that we're trying to connect to a new computer.  Windows 10, 8th gen i5, 16 GB RAM, etc.  I salvaged an old serial port to COM line header on motherboard, the instrument is connected to that.  Device manager says the port is operating but when I open the VISA test panel I get this error:

.VISA:  (Hex 0xBFFF001D) The specified attribute is not defined or supported by the referenced resource.

I installed the drivers anyway and tried to get a measurement but of course it timed out, I just figured it was worth a shot.

I've googled this error and browsed the forums but haven't found a good answer on how to get them communicating.  Does anyone have some insight?

Also I'm really new to this, no LabView experience, learning from tutorials and forums.

Cheers,

[sarahmo]

Hi,

What versions of VISA and LabVIEW are you using?

-Sarah

[AnonymousChemist]

Hi Sarah,

I'm using the latest labview and VISA.  I've learned that I've made a mistake in assuming it wasn't communicating.  I believe the issue may be in the instrument configuration.  Not the port configuration as the baud rate, etc. all match up.  In the VISA test panel IO settings when I turn on the termination character then query the instrument I can get it to read the model and serial number.  But when I use the Keithley drivers I've downloaded and use one of the example programs, I attempt to get a read or a continuous run then I'll get a timeout error.  It's like the instrument isn't sending any data maybe, I've changed the timeout to 5s from the 2s and that still doesn't help. Not sure how to troubleshoot this.

[AnonymousChemist]

Hi Sarah,

As an aside I connected the analog output of the Keithley to an NI DAQ and I'm able to use Signal Express (don't know how to set this up in LabVIEW) to monitor the current.  The instrument is collecting and communicating.  There just seems to be an issue getting LabVIEW to read from the RS232.

Cheers,