MFS data bytes (SLU P)

Bytes 5 through the end of the header can contain up to four MFS fields, depending on settings in message descriptor 1, bits 6 and 7, and message descriptor 2, bit 0.

If bit 0 is on, the first field, if present, is a 2-byte MFS DPM version identification. This field is present for all MFS DPM formatted output. The field can contain a version ID, or the value 0 (zero). In either case, one of the following fields (second, third, or fourth field) is present.

The second field, if present, is 2 to 9 bytes long and contains a 1-byte length indicator, including length byte followed by a 1- to 8-byte MFS MID name. This MID name field is present if the message output description contains the name of the MID to be used for the next input message, and should be returned to IMS by the controller program.

The third field, if present, is 2 to 9 bytes of data name, as defined by the paging option for the MFS device format.

The fourth field, if present, is 2 to 17 bytes long and contains a 1-byte length indicator, including length byte followed by a 1- to 16-byte user-specified MFS forms literal. The forms literal identifies the special setup or forms required for this message. The user must define the procedure to be followed at the terminal upon receipt of the forms literal.

The message format name (FMT statement label) is present if OPTIONS=MSG is specified; the logical page name (DPAGE statement label) is present if OPTIONS=DPAGE is specified; the presentation page name (PPAGE statement label) is present if OPTIONS=PPAGE is specified. This field appears in all output (message descriptor 2, bit 0) from DPM.

The content and format of the function management header for DPM formatted output can be influenced when defining the MFS device format through the HDRCTL=FIXED or HDRCTL=VARIABLE option. If HDRCTL=VARIABLE is specified, each MFS header field is variable in size. If HDRCTL=FIXED is specified, the following MFS header fields are sent and padded to their maximum size.
  • The MID name field in the output header is padded with trailing blanks for the maximum length of 8 bytes. Eight blanks are sent if no MID name is specified to format the next input through the user-supplied message output description.
  • The message format name is padded to a maximum length of 6 bytes. The logical page name or the presentation page name is padded to a maximum length of 8 bytes.