We ran into this error using an HP cluster, a Compaq MDR, and an IBM tape library. Although the error says that the device CPQKGPA2 (in our case) did not respond, the tape library can be contacted without problems.
We have the same problem but in our case with Veritas software. The event id is number 15, and error text: "The device, \Device\Scsi\CPQKGPSA1, is not ready for access yet.". It usually occurs once a week, and the only solution is to restart the server.
This event is common to many controllers. See ME154690
and event id 9 from adpu160m.
The problem is occurring when third party backup software Commfault Galaxy cannot find the Tapelibrary by using de MDR. In our case, the only workaround is to shutdown and power off the Tapelibrary, power off the MDR, shutdown, and power off the SAN server, and then startup the Tapelibrary first and wait till is online, power on the MDR and finally power on the SAN Server. The problem is occurring randomly and very often (once a week).