An indication of the connect state of this PORT.
Basically, this gives a higher level view of the
state of the connection by grouping PCM states and
the PC-Withhold flag state. The supported values
and their corresponding PCM states and PC-Withhold
condition, when relevant, are:
disabled: (PC0:Off, PC9:Maint)
connecting: (PC1(Break) || PC3 (Connect) || PC4
(Next) || PC5 (Signal) || PC6
(Join) || PC7 (Verify)) &&
(PC_Withhold = None)
standby: (NOT PC_Withhold == None)
active: (PC2:Trace || PC8:Active)