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Resolve VISA Connection Errors


If you are unable to connect to a VISA device using the visadev interface, follow these troubleshooting steps.

Possible Solutions

Configuration and Connection

  1. Make sure your device is powered on and all cables are properly connected.

  2. Make sure that you have the correct instrument driver installed for your device. Refer to your device documentation and the vendor website.


    If you are connecting to a GPIB device using an NI GPIB adaptor, you must download the NI-488.2 driver compatible with your VISA driver version from the NI website. The NI-488.2 driver is not available as an Instrument Control Toolbox™ support package.

  3. Make sure that your device is supported in Instrument Control Toolbox. See Is My Hardware Supported? and Instrument Control Toolbox Supported Hardware.

  4. Make sure that Instrument Control Toolbox recognizes your device, by using the visadevlist function.

    resourceList = visadevlist
    resourceList =
      6×6 table
                            ResourceName                         Alias                  Vendor               Model       SerialNumber     Type 
             __________________________________________    _________________    ______________________    ___________    ____________    ______
        1    "USB0::0x0699::0x036A::CU010105::0::INSTR"    "NI_SCOPE_4CH"       "TEKTRONIX"               "TDS 2024B"    "CU010105"      usb   
        2    "TCPIP0::"          "Keysight_33210A"    "Agilent Technologies"    "33210A"       "MY57003523"    tcpip 
        3    "ASRL1::INSTR"                                "COM1"               ""                        ""             ""              serial
        4    "ASRL3::INSTR"                                "COM3"               ""                        ""             ""              serial
        5    "GPIB0::5::INSTR"                             "FGEN_2CH"           "Agilent Technologies"    "33522B"       "MY52800145"    gpib  
        6    "GPIB0::11::INSTR"                            "OSCOPE_2CH"         "TEKTRONIX"               "TDS 1002"     "0"             gpib  

    Create a visadev object using one of the resource names listed. If your instrument is not listed, it might not be configured properly in your VISA vendor’s configuration utility software.


    VISA-TCP/IP, VISA-Socket, and VISA-Serial instruments and devices might need to be added manually in the VISA vendor's configuration utility to appear in the visadevlist output.

VISA Driver Configuration

If you are still having connection or communication issues with your instrument using VISA, you can troubleshoot using your VISA vendor's software and utilities, as described in the following table.

VISA VendorConfiguration UtilityTesting ConnectionDebug Utility
Keysight® VISAKeysight Connection Expert (KCE)Interactive IO button on KCEIO Monitor button on KCE
NI-VISANI Measurement and Automation Explorer (NI MAX)Tools > NI VISA > VISA Interactive ControlTools > NI I/O Trace
Rohde & Schwarz R&S VISARsVisaConfigure, launched from RsVisa Config tab on RsVisaTesterRsVisaTesterRsVisaTraceTool, launched from RsVisa TraceTool tab on RsVisaTester
  1. Use the VISA Conflict Manager settings from your VISA vendor's configuration utility to make sure that you have a preferred VISA set and that it is enabled. Check if all the VISA interfaces are using the expected VISA. For R&S VISA, make sure it is set to "Preferred". For example, for the Keysight Connection Expert, do the following.

    • Open the settings menu and select Tools > VISA Conflict Manager.

    • Under Enabled Implementations, make sure that your VISA vendor is selected.

    • Under Preferred Implementation, make sure that your VISA vendor is selected.

  2. If you are using SCPI commands, check if your device responds to them as expected when they are issued from the configuration utility.

  3. Use your VISA vendor's configuration utility to make sure that your device hardware is being detected. You can also check that your device responds to a *IDN? query.

  4. Use your VISA vendor's debug utility to check the Instrument I/O traffic for errors other than timeout errors.

  5. Try installing a different supported VISA vendor's driver.

Interface-Specific VISA

You can use other Instrument Control Toolbox interfaces to troubleshoot VISA. Try connecting to your devices using these interfaces.

  • VISA-TCP/IP — tcpclient interface

  • VISA-Serial — serialport interface

See Also

Related Topics