Specification of message output descriptor name

Output messages destined for MFS terminals are formatted using a message output descriptor (MOD).

Which MOD IMS uses can be specified within the output call, either insert (ISRT) or purge (PURG). Both ISRT and PURG allow you to specify an output MOD name parameter on the call that provides a segment of an output message.

When the output MOD name parameter is specified, IMS uses the name supplied to select the message output descriptor. If the call is directed to the TP PCB or alternate response PCB, IMS updates the MESSAGE OUTPUT DESCRIPTOR NAME field of the TP PCB with the name supplied in the output call. The MOD name of all output messages inserted on an alternate PCB that did not explicitly specify a MOD name is set to the previous MOD name.

Which MOD IMS uses to format the message depends on the name specified:

Name Specified: Descriptor Used
Valid output MOD name: Message output descriptor named by output MOD name
Eight blanks: IMS default message output descriptor (3270 or SLU 2 only—other devices use IMS basic edit for output)
Invalid output MOD name: IMS error default message output descriptor

If the output MOD name parameter is not specified, IMS formats the message using the MOD named in the MESSAGE OUTPUT DESCRIPTOR NAME field of the I/O PCB.