An application can monitor the status of the BCPii address space itself by using the ENFREQ LISTEN service and specifying the appropriate QUAL values to monitor when the BCPii address space becomes active and when it terminates:

• BCPii signals an ENF68 with a QUAL value of 01000002 when the BCPii address space becomes active.
• BCPii signals an ENF68 with a QUAL value of 01000001 when the BCPii address space becomes unavailable.

While it is possible to use the HWIEVENT service to allow an application to register for the Hwi_Event_BCPiiStatus event, this is not a recommended way to monitor initialization or termination of the BCPii address space. When the BCPii address space terminates, BCPii asynchronously asks the system to delete all ENF registrations made on behalf of applications that have issued HWIEVENT Add requests. If the deletion of the ENF registration occurs prior to the BCPii address space termination, the ENF exit will no longer receive control when BCPii signals that it is down.