POLLING SUBSTATE

         State of a tributary as determined by the polling algorithm. This
 	attribute applies only when the value of the link's protocol
 	characteristic is set to control. The value of this attribute is
 	affected by the value of the characteristic polling state. If the
 	characteristic  polling state is set to automatic, the value of
 	this status attribute reflects the current state of the polling
 	algorithm. For all other values of the polling state characteristic,
 	the values of both attributes are the same.

         ACTIVE -   The tributary is active and responds with data when
                    selected.

         DEAD -     The tributary did not respond when selected within the
 	           appropriate timeout period, when already in the Dying or
 	           Inactive state. The tributary will be ignored until the
 	           station reinitializes.

 	DYING -    The tributary, currently in the Inactive or Active state,
 	           has not responded within the appropriate timeout period
                    when selected.

 	INACTIVE - The tributary has not sent any data when selected by the
 	           control station. However, the tributary has responded with
 	           an appropriate message when selected.

     PROTOCOL STATE

         State of the data link protocol with the remote station.

        	HALTED -      The protocol is stopped and no messages are being
                       exchanged with the remote station.

 	RUNNING -     The protocol is on line and is exchanging messages
                       with the remote station.

 	STARTING -    There is an attempt to initialize the protocol between
                       the local and remote stations. This uses the STRT and
                       STACK PDUs.

 	MAINTENANCE - The protocol is off line and dealing with maintenance
 	              messages only.

     STATE

         Operational state of the local logical station.

         OFF - The station is disabled.

         ON  - The station is enabled.