Solution
This description indicates that the instrument was found but that it did not respond to a *IDN? query. The *IDN? query is a common identification query command which is specified in the Standard Commands for Programmable Instruments (SCPI) standard. Most instruments accept this command because the 488.2 Standard was modified in 1990 to include SCPI commands.
If you get this message, it is likely that your instrument is configured correctly, but was made before 1990 or is not SCPI compliant. This is an expected behavior. Check the instrument's manual to verify proper commands and use those commands to test communication with the instrument.