Monitoring, Communication & Signal Transmission
Central station monitoring, ULC S559 communicators, alarm transmission testing, surge protection, network pathways, environmental ratings, and two-wire bases.
- Explain central station monitoring and ULC S559 communicator requirements
- Describe alarm transmission testing and signal verification procedures
- Identify surge protection and lightning grounding requirements
- Explain sequence of operations, environment ratings, and two-wire base systems
Lesson 1
Central Station Monitoring & ULC S559 Communicators
Central Station Monitoring
A central station is a facility staffed 24/7 that receives alarm, trouble, and supervisory signals from fire alarm systems and dispatches the appropriate emergency response.
Communication Pathways
The fire alarm communicator transmits signals to the central station via:
- Digital Alarm Communicator Transmitter (DACT) - uses telephone lines
- IP communicator - uses internet connection
- Cellular communicator - uses cellular data network
- Dual-path - two independent pathways for redundancy
Exam Tip
ULC S559 covers fire signal receiving centres and communicator equipment. The communicator must transmit signals within 90 seconds. Dual-path monitoring uses two independent communication methods for reliability.
CAN/ULC-S561 Central Station Requirements
- Staffed by trained operators 24 hours a day, 365 days a year
- Must process alarm signals and dispatch fire department within prescribed time
- Must notify building owner/manager of trouble and supervisory signals
- Must maintain records of all received signals
- Listed by ULC to CAN/ULC-S561
Communication Supervision
The FACP must supervise the communication pathway:
- Loss of the communication path generates a trouble signal at the panel
- For DACT systems, telephone line integrity is checked periodically
- IP and cellular communicators send periodic test signals (heartbeat)
- Dual-path systems generate trouble only if both paths fail
Central stations are staffed 24/7 and receive signals via DACT, IP, or cellular communicators per ULC S559. Signals must be transmitted within 90 seconds. Communication path failure generates a trouble signal at the FACP.