You define APPC/MVS start parameters in system PARMLIB member APPCPMxx (for example, SYS1.PARMLIB(APPCPMxx)). The APPC/MVS start parameters contain information for establishing and controlling APPC conversations on the system. They identify the local LU to be used for APPC conversations, and the TP profile and side information data sets to be used by APPC/MVS.

On z/OS®, Distributed FileManager conversations flow over the LU defined as the base LU in APPCPMxx. The TP profile data set provides APPC/MVS with the DFM TP profile information. The TP profile information enables DFM to participate in APPC LU 6.2 conversations.

You can control APPC/MVS start parameters by using different versions of APPCPMxx. Each version can have different values for the start parameters. For example, one version can omit an LU name that is included in another version.

APPC/MVS is started by a system operator command. The operator command (which can be part of initial program load) identifies APPCPMxx (see Starting APPC/MVS). Both APPC/MVS and the APPC/MVS transaction scheduler (also started by operator command) must be active before DFM LU 6.2 conversations can take place.