Using ENF event code 67 to listen for check status changes

If your check is authorized, it can use the ENFREQ LISTEN service to detect check status changes. On the ENFREQ service, specify theX'20000000' status change event qualifier and the listener user exit routine that is to receive control after the specified event occurs. The listener user exit specified receives control when IBM® Health Checker for z/OS® comes up and notifies the check routine of the status change.

To listen for ENF event code 67, you must specify the qualifying events on the BITQUAL parameter, which specifies a 32-byte field, a hexadecimal constant, or a register containing the address of a 32-byte field containing a bit-mapped qualifier that further defines the event. The qualifier is mapped by mapping macro HZSZENF. The BITQUAL value for the status change event is Enf067_BitQual_StatusChange in the HZSZENF mapping macro. This might mean on eof the following:

The check completed with a different result than the last time it ran. For example, the check ran successfully after the previous check run issued an exception or vice versa.
The check was deactivated or deleted

The check then might want to issue the HZSQUERY macro to get information about the check.

This event may not be presented if IBM Health Checker for z/OS is terminating (indicated by a X'40000000' ENF 067 event for NotAvailable - see Using ENF event code 67 to listen for IBM Health Checker for z/OS availability).

If the check routine decides it is no longer interested in knowing if IBM Health Checker for z/OS is up or not, it can issue the ENFREQ REQUEST=DELETE request to delete the listen request.

For information about ENFREQ and listener exits, see: