How to poll to determine if device is connected to GPIB bus?

[dantheman]

I am using the ESP-488 engineering support package to implement a driver for the GPIB-ENET/100. How do I use functions in the driver to determine whether or not a device at a particular GPIB address is connected to the GPIB bus?


-Daniel

[Ray K]

Use ibln to check if there is a listener at the address. If there is, and you want to identify it, write an identification query to it and read the response back.
Ray K
NI applications Engineer

[dantheman]

Thanks for your response. I am unable to use ibln, because I am using the ESP-488 on VxWorks to communicate with my GPIB-ENET/100. The ESP-488 does not support the ibln function. Could you please send me an implementation of ibln for the ESP-488?

-Daniel

[Ray K]

I don't have an implementation of ibln for the ESP-488, but you can also just write a write a standard ID query to the device(most instruments respond to *idn?) and read back the response. If the the write fails with an ENOL error, that means a device is not at that address.

[dantheman]

Not all of my instruments are 488.2-compliant (that is, they only conform to the older 488.1 standard) and don't support the *IDN? command. Would I still be able to issue an arbitrary command to these instruments and get a different error depending on whether or not there was an instrument at the specified GPIB address?