Logical link path control

You can use several commands to control logical link paths. The logical link path is the lowest level of control across a Multiple Systems Coupling (MSC) environment because it is the lowest level that is necessarily defined in intermediate MSC systems.

Logical link paths are defined by SYSID pairs that identify the sending and destination systems. You define logical link paths using the MSNAME system definition macro or by using the type-2 CREATE MSNAME command. The following table summarizes the commands you can use for link control.

Table 1. Commands used to control MSC link paths
Command Keyword MSC use and effect
/START MSNAME Start a previously stopped MSNAME.
/STOP MSNAME Stop the sending or receiving of primary request messages associated with the logical link path.

When stopped by an input system, primary requests for remote programs or terminals associated with the stopped logical link path are canceled and IMS returns message DFS065 to the input terminal. Conversations in progress are allowed to continue.

When stopped by a destination system, messages received from other systems over a stopped logical link path cause a logical link path to be stopped in the sending system (input or intermediate); IMS issues messages DFS2140 and DFS2142 (respectively) to the MTOs of the sending and receiving systems. Messages remain enqueued in the sending system until the logical link is subsequently started in both systems.
/PURGE MSNAME Halt enqueuing of primary requests for all remote terminals and programs represented by the MSNAME. Continuing conversations and secondary requests are still handled. Primary requests entered through an input terminal receive message DFS065. Requests from other systems that require use of the logical link path for a response are not accepted, but remain enqueued in the sending system (see /STOP MSNAME above).
UPDATE MSNAME SET(), START(), and STOP() Using the UPDATE MSNAME command, you can set or change various logical link path attributes, including starting and stopping the queuing or sending of messages to logical link path. The command requires the Operations Manager (OM) API. The command syntax for this command is defined in XML and is available to automation programs that communicate with OM.