Specifying trace options

Use the SUBS= parameter on the OPTIONS statement to specify trace options for external subsystems.

If you want to trace the connection and disconnection activities of IMS to the external subsystem, the parameter SUBS= on the OPTIONS statement must be set to ON. Specifying OUT on this parameter causes trace information to be written to the log. If this parameter is omitted, traces can be turned on and off with the /TRACE command.