LabVIEW programme not recognizing keithley 6487

[gperis]

Hi all,

Back in the day I had a labview program that allowed me to run a voltage sweep with a Keithley 6487. Now I'm trying to use the same program on a different computer with a different Keithley 6487 and I cannot make it work. Windows versions from both computers are the same (W11) and labview versions too (labview 2021). We are using the Keithley 648X driver, and each time we try to initialize the device I get a -1073807360 error (see attached picture). I'm using a serial-usb to connect the device to the computer, and I've checked the configuration in both the device and the labview programme are the same (baud 9600, flow control none, terminating term CRLF, paraty none, 8 bits, 1 bit stop). The device configuration is set to communicate via serial connection, RS232. Does anyone know what could be happening?

[rolfk · Accepted solution]

Try to switch those USB-Serial adapters. They are by far not all of the same quality and their drivers are also VERY different quality wise. Counterfeit chips are also a possibility, with the device claiming to be FTDI for instance, which is usually working fine, but being some "Jin-Yang Sing" device in reality. FTDI has modified their driver (which are also shipped with a standard Windows install) in the past to try to detect such chips and simply returning an error when someone tries to access the device. While some application pretty much ignore most errors, VISA is relying on the return status of the driver calls to be something useful.

[gperis]

Hi Rolf,

thank you very much for your answer. I bought a new usb-serial cable, exactly the same model I had used in the past in my previous set-up, and I keep finding the same error. Do you have any other suggestion of how I can try to fix this problem?

Miguel

[gperis]

Update: I actually installed the drivers of the cable and it worked!