How MFS formats input messages

Input data from MFS-supported devices in formatted mode is formatted based on the contents of two MFS control blocks—the message input descriptor (MID) and the device input format (DIF). The MID defines how the data should be formatted for presentation to the IMS TM application program and points to the DIF associated with the input device. The DIF describes the data as the data is received from the device.

If the message built by the MID is a command, the command must conform to the command format and syntax rules as documented in IMS Version 15.3 Communications and Connections.