• Low Level GPIB Communication with 2611B

    I have a 2611B connected via a Keysight Technologies 82357B USB to GPIB adapter.

    I'd like to communicate with the 2611B using low level GPIB commands, possibly without some other additional layer.
    I have a small routine that just sends the command over GPIB and receives a string, but I first tried to use the Keysight Interactive IO tool.

    If I send

    *IDN?

    I receive

    Keithley Instruments Inc., Model 2611B, 4038432, 3.0.3

    so the connection itself should work.

    But even simple commands like

    :SYSTem:LFRequency?

    just result in a timeout.

     ! VI_ERROR_TMO: A timeout occurred
    Visa ErrorCode: 0xBFFF0015 (-1073807339)

    Can somebody tell me how to make the 2611B respond to my requests?

    Thanks!