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PyVisa | Trouble I identifying Resources | Rigol DS1054 | Keithly 2200-20-5

dustin1986

Hi I am new to automating lab equipment. I am playing around with an oscope and psu to learn. I am using the usb connections. I am using Manjaro linux. I have the usbtmc driver installed and working. My linux box does see the instruments when I plug them in. However, pyvisa doesnot seem to find them. I just get a long list of ASRL "devices" no way to identify which one is the hardware I attached.  

image

Does pyvisa not see the hardware or is thee another way to find devices?

  • in reply to dustin1986

    Oh, right. Keithley/Tek is licensed. I forgot you said you were using one of their PSUs.

    pyvisa is a wrapper for the VISA driver. Example VISA drivers are:

    1. NI-VISA
    2. R&S VISA
    3. Keysight IO Connect (or whatever they call it now)
    4. pyvisa-py

    I know it is confusing because the name is so similar. "pyvisa-py" is a pure Python VISA implementation. "pyvisa" is the wrapper. (also pyvisa-py is not installed automatically if you pip installed pyvisa.)

    The pyvisa maintainers specifically write pyvisa to work as a wrapper for NI-VISA. So, if you can use NI-VISA, that is your best option. pyvisa-py is less feature0rich and is only a good option if you have no other VISA driver.

    The VISA driver is what talks to the devices via USBTMC or TCPIP or Serial or whatever.

    The result is that if NI-VISA's configuration tool cannot see your devices, then pyvisa won't be able to either.

  • in reply to baldengineer

    On Linux this may become a stretch, but for Windows, Rigol (and other SCPI compliant manufacturers) supply a VISA runtime with their software install. Usually an OEM-licensed NI-VISA version ...

  • in reply to Jan Cumps

    Yeah, I think you still have to be careful there. Tier 1 manufacturers are generally covered. But some of the smaller (and very popular) companies are not. Some will even link their customers to NI's website, but they don't have a license agreement. They're just banking on the fact that their customer is using LabView.

    And, while I am not a lawyer, my read of the NI-VISA runtime license only covers using the manufacturer's "software," not generic SCPI usage.

    I know it is splitting hairs. But since NI is so purposefully restrictive, I would rather err on the side of caution.