Concept
Interconnection Integrity and Pathway Class
The interconnection pathways provided for communications between the smoke control system components, such as Smoke Control Servers (AS-P-AS), field controllers (IP, MS/TP and Infinet), Central IO modules and the IP alarm panel, are supervised with communications integrity monitoring. Also, the end-to-end critical control functions are supervised via end-device monitoring and feedback.
The Ethernet IP network, MS/TP and i2 communications pathways operate as Class B pathways. A Class B pathway is specified to operate as follows:
a) A redundant path is not included.
b) Operational capability stops at a single open.
c) Conditions that affect the intended operation of the path are annunciated as a trouble signal.
d) Operational capability is maintained during the application of a single ground fault.
e) A single ground condition shall result in the annunciation of a trouble signal.
f) Where operational capability must be maintained during a fault, the operational capability shall be restored within 200s of the application of the fault.
Note that criteria d and e are not required in smoke control applications because of exception #2 in section 50.3 of the 10th edition of the UL 864 standard.
The control of smoke control equipment (such as fans and dampers etc.) presented on the FSCS is supervised through process feedback sensors or contacts and operates as Class C pathways. A Class C pathway is specified to operate as follows:
a) One or more pathways are included.
b) Operational capability is verified via end-to-end communication.
c) Monitoring the integrity of individual paths is not required.
d) A loss of end-to-end communication shall result in the annunciation of a trouble signal.
Note that the signal returned from these sensors to the controller provides the end-to-end (criteria b) and a failure anywhere in the equipment activation process is reported as a trouble signal on the FSCS (criteria d).
Basic Application Functions
General Communications Conventions
FSCS Communication Status
Equipment Fault Detection
Weekly Self-Test