In order to measure the transfer curve of the transistor, two Keithley 2400 are connected via a Prologix GPIB USB controller. The port and values are correctly identified, and I confirmed that each device works individually during tests. However, when both are used simultaneously, the sweep does not proceed, and as shown in the first photo, it is stuck. An error appears (as seen in the second photo), and a 410 error is identified on one of the devices. Upon checking, I found a “Query Interrupted” error. So I putted delay module in between loop and SMU, but still doesn’t work. How can this issue be resolved?
First of all, you could try to migrate to SweepMe! 1.5.6, our latest version that can be installed in parallel to your currently used version SweepMe! 1.5.5, maybe the problem is already solved there.
It looks like the second SMU does not get any values back. Can you add your settings files so that I can see which port strings you are using for each SMU module? Or send a screenshot of each SMU module.
While both SMU modules need to use Prologix adapter with the same COM port, the number that indicates the GPIB port needs to be different and in accordance with the GPIB port set at the instrument. Further, the GPIB ports of both Keithley 2400 must differ, for example they should not be “24” at the same time. This could also explain why single instruments work but not if they are used together.
Query interrupted (error 410) can happen if you send a command to an instrument while it is still processing another one. So, if you accidentally send the command to read the results to the same instrument two times in a row, such an error could appear at the Keithley 2400 that is related to the given communication port.
