To receive notification of an event, your server must supply a buffer on its call to Get_Event. APPC/MVS returns the event element in the event buffer.

The event buffer you specify must be large enough to contain the event element. If you specify a buffer that is not large enough, APPC/MVS sets the event_element_size parameter to the length it requires to satisfy the request. The Get_Event service returns to the server with return code 16 (atbcts_request_unsuccessful) and reason code 41 (atbcts_buffer_too_small). The server can create a larger event buffer and call the Get_Event service again to retrieve the event element successfully.

If you specify a buffer large enough to contain the event element, APPC/MVS sets the event_element_size parameter to the size of the event element that was returned, and the server receives a return code of zero.

Like most parameters returned from APPC/MVS callable services, the event buffer must reside in the caller's primary address space and be accessible to the caller's PSW key.