Working With System Image Definitions › How You Specify Messages in a Resource Definition › Special Message Prefixes

Special Message Prefixes

Normally, a resource definition in an active system image recognizes only messages for the corresponding resource. However, the following special message prefixes are available to enable a resource definition to handle special types of local messages. You cannot combine prefixes.

$AA-

A resource definition can generate a user-defined resource event. For another resource definition to recognize the event message, you must prefix the message by $AA- when you specify the message rule in that definition.

For example, ALERT - VTAM AVAILABLE is specified as the event message on the Define Event Related Action panel of a resource definition. To enable the resource you are defining to recognize that message, you must specify $AA-ALERT - VTAM AVAILABLE as the message text to look for.

$DN-

A message can be a delete operator message (DOM) notification. For a resource definition to recognize a DOM notification, you must prefix the message by $DN-.

For example, specifying $DN-IEF233A M 380 enables a resource definition to recognize the DOM notification for the tape mounting request message IEF233A M 380.

$MN-

A resource definition recognizes messages that relate to the resource itself only. For a resource definition to recognize messages from other resources and from the operating system, you must prefix the messages by $MN-.

For example, you might want to detect the starting and the stopping of a batch job that performs system backup. Detecting those messages enables you to stop and restart a resource, as required, by changing the desired state of the resource through the SVCMD macro in a process.