Operator logical paging

Operator logical paging allows you (or, for SLU P, a remote program, or ISC subsystems) to request a specific logical page of an output message. It is defined on a message basis in the PAGE= operand of the MOD's MSG statement.

Functions provided

When a MOD is defined to allow operator logical paging, the following functions are available to you once the first physical page of the output message is displayed:

  • Enter = to display the next logical page of the current message.
  • Enter =n, =nn, =nnn , or =nnnn (where n is the logical page number) to display a specific logical page of the current message. The maximum value for nnnn is 9999.
  • Enter =+n, =+nn, or =+nnn to display the n th logical page past the current logical page. The maximum value for nnn is 999.
  • Enter =-n, =-nn, =-nnn , or =>nnn to display the n th logical page before the current logical page. The maximum value for nnn is 999.
  • Enter =L to display the first physical page of the last logical page of the current message.

Format design considerations

When operator logical paging is permitted, message and device formats should be designed to allow you to enter the page request onto a currently displayed page and have the request edited to the first field of the first input segment. If this is not done, or the PAGEREQ function is not used, paging requests can only be entered on a cleared device.

Preferably, the installation standard for device formats should include a specific device field for you to enter logical page requests, transaction codes, and IMS commands. If the transaction code is normally provided through a message or program function key literal, the PAGEREQ function can be used, or a field can be defined at the beginning of the first segment using the null pad character. A page request field on the device can map to this field. If you do not enter a page request, the null pad causes the field to be removed from the segment and the second field (literal transaction code) appears at the beginning of the segment.

Transaction codes and logical page requests

If the PAGEREQ function is not used to specify a page request, MFS formats input data according to the defined MID prior to determining whether operator logical paging was specified, and whether the input contained a page request. If operator logical paging was not specified, the message undergoes standard IMS destination determination.

If operator logical paging was specified, MFS examines the first data of the first message segment (first field if the message uses format option 3) for an equals sign (=). If MFS does not find an equals sign, it routes the message to its destination. If an equals sign is present, all following characters up to a maximum of 4, or the first blank, are considered to be a page request.

A message destined for a single-segment command or transaction, as required in Fast Path applications, should be defined as single-segment in its MID. If the MID defines more than one segment, you must ensure that only one segment is created when the destination is a single-segment command or transaction. This can be achieved by careful input and the use of option 2, null compression (FILL=NULL) or both.