Detector Id Switches; 120Ohm Termination Resistance - CGS Merlin 'S' Range Installation, Fonctionnement Et Entretien

Installation, Operation & Maintenance Manual
Split Detector Chain from Control Panel example.
Reversing the [D+] and [D-] connections of any device can lead to the whole system to stop working owing to reverse
polarity found on the terminals. In order to avoid this problem, it is recommended that the cable of same colour
should be used to connect all [D+] terminals together and similarly cable of same colour to be used to connect all [D-]
terminals together.
The detector must be earthed/grounded for electrical safety and limit the effects of R/F & EMC interference!
Where cable runs may exceed 100 yards from one control panel – Contact your supplier!
Ensure the 120ohm termination resistance switch is turned on at each end of a cable run!

Detector ID Switches

When wiring multiple detectors it is important to identify each detector installed for
the control panel to receive and display accurate data corresponding with the
correct device.
The ID configuration diagram is printed onto detector boards for quick
reference as shown opposite. All detectors are factory set to ID1.
We recommend a plan, map and/or marking the detector enclosures detailing ID and location!
ID Switches must be configured for each detector connected to receive and display accurate data!

120ohm Termination Resistance

Signal communication issues may occur where the bus length is too long, high baud rates are
used or signal reflections are occurring. To avoid this, terminating at each end of a chain
may help the quality of the data signal by turning on the 120-ohm terminal resistor switch.
If a split chain is used, terminate the last detector in each chain.
If a single chain is used, terminate the first device (Panel) and last device (Detector).
Split chain
IOM Iss: 4 11-21
Single chain
Merlin Detector-TFT
7