Frequently Asked Questions
The Signaling Line Circuit
- 1 Just What Is a Signaling Line Circuit (SLC)?
- 2 Are Addressable Fire Alarm Systems Different from Conventional Systems?
- 3 What is the Difference Between an Addressable System and a Conventional System?
- 4 What is the Difference Between Electricity Flow and Signal or Power Flow?
- 5 NFPA's 7 Classes of Fire Alarm Paths
Supervision & T-Taps on the SLC
- 6 What Is Addressable Supervision?
- 7 Is an EOL Resistor Needed for an Addressable System?
- 8 How many T-Taps are allowed on a Signaling Line Circuit (SLC)?
Programming and Addressing the Devices
- 9 How do You Use the Switches for Addressing?
- 10 Can a Control Module & Pull Station Address be Sequential?
- 11 It's the Volunteer Firefighter that Reads the Panel
Signals and Multiplexing
- 12 What are the Signals on the SLC?
- 13 Is the Signaling Line Circuit (SLC) a Data-Power Bus?
- 14 How Does Multiplexing of the Signaling Line Circuit Work?
- 15 How does an SLC Carry Both Signals and Power?
Modules and Devices
- 16 How Does the Panel Know the Address?
- 17 Why are Modules Needed in a Fire Alarm System?
- 18 What is Voltage Free Interfacing?
- 19 Can I use an Addressable Detector on a Conventional Panel?
Connecting Panels and Devices
- 20 Can an SLC Power a Horn or Strobe?
- 21 Can the Input and Output Wires on a Speaker be Reversed?
Troubles on the SLC
- 22 What Happens to the SLC when a Device is Disconnected?
- 23 Why Can't You Reset a Trouble on a Fire Alarm Panel?
- 24 Why Can't I Reset the Panel After Disconnecting the SLC?
- 25 Why Won't the Panel Show the Detectors?
- 26 How do I Fix a Damaged Loop?
Wire Length and Capacitive Lag
- 27 How does Capacitance and Shielding Affect Wiring?