Wire Relay Connection; Rs-485 Communication Network; Figure 19 - 4 Wire Relay Connection - GasTech F-GUARD UVIR User Manual

F-Guard UV-IR User Manual Doc. No. F110V0020.06
2.9

4 Wire Relay Connection

This wiring option uses the fault and alarm relay and is connected to fire alarm panels. This
connection allows connecting of several detectors on 4 wires in a single loop. On the last detector,
there is a connected EOL resistor in the connection box. The value of the resistor depends on the
control panel specification.
The number of detectors in a single loop depends on the control panels power supply capacity and
length of wire width.
In a fault condition, the fault relay will open the contact. The control panel will see an open-loop and
will report a fault.
In alarm conditions, the alarm relay will close the contact and short the loop. With this configuration,
the panel does know which detector in the loop caused the alarm or fault. See figure below.
F 19 - 4 W R C
IGURE IRE ELAY ONNECTION

2.10 RS-485 Communication Network

Using the RS-485 network capability of the detector and communicator software, it is possible
to connect up to 32 detectors in an addressable system with only 4 wires (2 for power and 2 for
communication). Using repeaters, the number of detectors can be much larger (32 detectors for
For more information & Technical support: info@gastech.com and support@fg-detection.com 19