VISA Read Timout

[bonnerupc]

Hello,

Using LabVIEW 2020 and the certified Keithley 648X instrument driver package.

I have (2) PC'S running Windows 10 64-bit; LabVIEW on both machines.

One one machine, the Initialize routine finishes nicely with no errors.  On the other, (refer to the snippet), timeout occurs waiting for bytes which is set to 256 immediately after the Error Query Command.  It appears the code is not 'automatically' stopping when a new-line is received, even though that is set in the routine.  If I wire the 'Bytes at port' indicator, (10 Bytes) code progresses normally with no error.

On the other machine, this is not happening. 

All settings, as far as I can tell, are identical on both.

Only difference is the machine this is occurring on is 2020 SP!; the other is not.

Strange.  Any suggestions?

Thanks,

Chris

[ahovhann]

Hi,

Have you tried to run the vi only with LabView 2020, not SP1?

[bonnerupc]

Thanks,

Yes.  Even tried 2019.

Chris

[bonnerupc · Accepted solution]

Solution found.

Seems the original Keithley 648x LabVIEW Driver is programmed to assert a simple line feed for termination of VISA reads and writes.  For 'writes' this is acceptable, but 'read' responses are terminated by CRLF; my ver. of VISA would not accept a simple LF.  Fortunately, the 648x unit will accept CRLF for both reads and writes and all ate happy now.

[ahovhann]

Hi,

Thank You for sharing the solution