visadevllist won't show usb/tcpip type devices, only gpib is displayed

my script on the same PC & equipment.

In the last few weeks, visadevlist refuses to display any other type of device other than gpib.

However, useing Matlab-App Test and Measurment tool, I can see my tcpip and usb devices, and I can connect to them.

It seems just the visadevlist won't show them. My script relies on visadevlist to auto-determin available resources.

Please advise.

Answer 1

[Manoj Mirge]

I understand that you have the USB and TCPIP devices connected to the machine but still the "visadevlist" function is not listing those devices in its output.

To resolve the issue kindly verify that the devices are properly connected to the machine. You can use the "visadev" function to connect to your device. Kindly refer to the below code for the same:

% ResourceName is a valid resource name string for the device you are trying to connect to 
>> device = visadev(ResourceName) 

To learn more about the "visadev" function, please refer to the following documentation link:

https://www.mathworks.com/help/instrument/visadev.html

If "visadev" fails, please ensure that you have a valid VISA driver installed, either from National Instruments or Keysight, and the VISA conflict manager in either NI MAX or Keysight Connection Expert is configured so at least one VISA driver is enabled and set as preferred.

If "visadev" works with all connected devices, this issue might occur because "visadevlist" tries to ping all connected devices, and some devices might sometimes take up more time than timeout to connect. Please try to increase the timeout length in the "visadevlist" function:

>> visadevlist("Timeout", 60);
% Above code sets the timout of 60 seconds.

To learn more about the "visadevlist" function, please refer to the following documentation link:

https://www.mathworks.com/help/instrument/visadevlist.html

Hope this helps.

[jiansong wan]

Hi Manoj,

I solved this problem by re-installing NI-MAX software.

It seems like a software glitches, preventing Matlab to discovering any device other than GPIB.

The command you mentioned can be helpful, especially the time out option.

Thanks!

Jiansong

[Shivam Kumar]

Thank you so much Manoj. Your answer helped me a lot.