What is an appropriate return value or code when device is disconnected?

[Vasay, Al]

Hi,

I am currently using the latest SNMP++ and AGENT++ on Windows NT.  

I have a general SNMP question -- Let's say that the only mib objects I have defined for a device is deviceName (string) and deviceID (numeric), and the SNMP Manager sends a "GET deviceName" or a "GET deviceID" request. But before this request was received by the Agent, the device was accidentally disconnected. Disregarding Traps, what is the best way to let the Manager know that the device has been disconnected. Is there an SNMP error code that I can return to convey that information?  What have you guys done in this situation? 

Thank you very much,
Al