A row represents the configuration of synchronous equipment timing
subsystem (SETS) of the system. Entries cannot be created and deleted
via SNMP SET operations. When a tmnxCpmCardEntry is created, a
tmnxSyncIfTimingEntry is created. SNMP set operations with
tmnxCpmCardSlotNum of the secondary CPM will be denied.
If the value of the reference source port is a valid Port ID then the
reference is a port. If the value of the source hardware is a valid
non-zero HWIndex then the source is the hardware specified by the
HWIndex.