Rules for CTC connections

• If both CHPIDs of the CTC connection are located on the source object, and both source CHPIDs are mapped to target CHPIDs, HCM ensures that the CTC connections are completed for the target object. HCM also ensures that CUADD values are also correctly set (if such a change is needed). This way, it is ensured that both physical and logical connections are established correctly on the target.

  This is also true if you have an FCTC connection over a single FC CHPID.

• If both CHPIDs of the CTC connection are located on the source object, and if just one of the source CHPIDs is mapped to a target CHPID, then a CTC connection is established between the new target CHPID and the unmapped source CHPID.

  The physical part of the link on the source CHPIDs is removed from the source CTC connection and is connected to the new target CHPID.

  As the logical connection between the source CHPID and the CTC control unit(s) and CTC device(s) is not disconnected, the Unused… button will be available on the CTC Connections dialog. For details on unused CTC control units, devices and connections to CHPIDs, see Editing a CTC connection.

  The Unused… button will also be available if just one CHPID of the CTC connection is located on the source object and is mapped to a CHPID on the target object, and if the connected destination CHPID is located on a different processor or channel subsystem. That is, HCM establishes the new CTC connection between the mapped CHPID on the target processor and the unmapped destination CHPID. The reason is as before, that the logical connection between the mapped source CHPID and CTC control unit(s) and CTC device(s) is not disconnected.

After successful copy operations, you should verify your CTC connections via the CTC Connections dialog and check whether some unused CTC control units, CTC devices or CTC CHPIDs are reported.