Keithley 2400 Sweep and concurrent measurement

[johnsold]

Does anyone know if sweep (source V) and concurrent measurements (V and I) are compatible on the Keithley 2400?

USB-GPIB interface (Keithley).  LV 8.5, Windows XP, VISA (recent version, not sure which one).

Keithley 24xx Sweep and Acquire Measurements.vi, an example VI from the driver downloaded from the NI driver pages.

When I run the example VI it usually hangs up at the VISA Write function inside the Fetch (Measurements).vi inside the Read (Multiple Points).vi.  The instrument displays an error -410 Query INTERRUPTED.  According to the manual this usually occurs if a second query is sent before the previous one has completed.  Putting a long delay in front of this does not seem to help.  The function preceding is a Wait for Operation Complete.vi which runs without error.  Interestingly, if I run the Close.vi (which does an error query and closes the VISA session), then run the Read (Multiple Points).vi as a stand-alone VI, it returns all the data.

In the 2400 User's manual all the examples of sweep programming turn off concurrent measurements. However, I could not find any statement that sweep and concurrent measurements were incompatible.  The example VI turns concurrent measurements on in the Default Setup.vi.  A posting by sinkovich in February indicated that he needed to turn it off, although is situation was a bit different.  

We would like to measure both voltage and current on the sweeps if possible.

I have the the meter in my office, but the USB-GPIB interfaces are not supported on the Mac so I cannot test here.

Any suggestions?

Lynn 

[Neil.Pate]

Lynn,

If memory serves me correctly this is possible.

The easiest way I got it working was to first get it all ticking along ok in their Lua based IDE, then once the script was working perfectly I just used LV to send the script as text to the instrument over GPIB. Worked a treat.

[Neil.Pate]

The reason I used the script approach was because their LV driver was not so good!

[johnsold]

We want to stay with an all LV version if possible (mostly because that is all I know).  The new driver is somewhat better than the old one - VISA based at least.

Thanks,

Lynn 

[Neil.Pate]

If I recall, their driver is really just the script language wrapped in VIs.

The driver I last used was from circa 2007, and was VISA based, but just didn't offer the right flexibility.