SLU 1 with MFS
During IMS system definition, you can define a SLU-1 terminal to work with Message Format Service (MFS). Like a 3270 terminal, system-supplied formats are available.
Even when defined to operate with MFS, the SLU-1 terminal operates in unformatted mode (using IMS basic edit) until one of the following occurs:
- You enter //midname.
- MFS processes an output message to the terminal using an MFS message output descriptor (MOD) that names an MFS message input descriptor (MID) to be used to process subsequent input data.
If you enter data on the same line as //midname,
separate //midname from the data
with a blank. IMS discards the //midname and
the blank, and formats the data according to the named MID. If you
enter //midname without any data
on the same line, IMS considers
the next line received from the terminal to be the first line of the
message.
When IMS processes an output message to a SLU-1 terminal using a MOD that names a MID, MFS uses that MID to format the next input from that terminal. An application program, the IMS /FORMAT command, a message switch, or some IMS functions can create this output message.
When in formatted mode (using MFS), a SLU-1 terminal remains in formatted mode until one of the following occurs:
- You enter two slashes (//) or two slashes followed by a blank. The terminal returns to unformatted mode, and IMS discards the two blanks. The two slashes are escape characters.
- You enter two slashes, a blank, and data. MFS returns the terminal to unformatted mode, IMS discards the slashes and the blank, and formats the data using basic edit.
- IMS sends an output message that does not name a MOD to the terminal.
- IMS sends an output message whose MOD does not name a MID to the terminal.
IMS uses MFS default formats for many output messages. When a terminal receives such a message, the terminal goes into formatted mode, and MFS processes the next input message unless you use the escape characters. If in doubt, use the escape characters.