Posted Fri, 21 Feb 2025 14:55:05 GMT by Nagl, Jakob
Hello,

I'd like to do delta-mode measurements with the Keithley 6221 & 2182A devices, controlling the 6221 through LabView 2015.
I have the 6221 and 2182A connected through RS232 null modem and trigger link cable, and the 6221 is connected to PC through GPIB bus. Controlling delta mode on the front panel works perfectly, so I'm sure the physical connections are correct. RS232 settings are also matching between the devices (i.e. 19.2k rate, Xon_Xoff flow control, CR terminal) and 6221 is in GPIB mode.

However, when running the delta mode example included in the LabView driver for model 6221 ("Delta Meas Example.vi"), there is a problem.
A connection is established to 6221 & 2182A, delta mode is started, armed and triggered (see attached front panel image).
But the data is never read in to model 6221 or the PC. Instead, after some seconds there is a LabView error: "ERROR -1" in "Read Trace Buffer.vi" with "Possible reason: Buffer data type is "NONE", thus there is no data in buffer."
I'm guessing the command to measure/get the data from model 2182A is never sent, so there is simply no data to read.
Does anyone know how to solve this issue?

Thanks!
 
Posted Wed, 26 Feb 2025 13:41:21 GMT by C, Andrea
Can you post an additional image of the LabVIEW front panel for what values you are passing to the VIs?
Posted Mon, 10 Mar 2025 12:14:34 GMT by Nagl, Jakob
As far as I can tell the settings do not affect the outcome. I can reproduce this error with the default options from the example VI, see below.

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