Detector Configuration; 4-20 Ma Output; Rs485 Serial Communication Output - Prosense PQ Series Installation And User Manual

Detector Configuration

The Prosense PQ detector has 4-20mA analogue output and RS485 Modbus serial
communication output features on main board. It is possible to install optional relay module

4-20 mA output:

to have three relay outputs for two alarm levels and fault status.
The default configuration provides single 4-20mA signal output. Prosense detectors can be
connected to control panels on the market having 4-20mA input signal. Signal wiring from
detector and the control panel should be carried out by shielded cables. Wires cross section
depends on the distance between the control panel and the detector. The details given in
power cabling are valid as well for signal output. We recommend using values given in Table-
4 as cabling best practices.
Please avoid any interruption in case any junctions on wires. The shield is to be grounded
from the control panel side only and never connect the shield to the detector. Please make
sure clutching or crimping apparatus are not loosened or oxidized.
To get the analogue output signal correctly and constant the load resistor on S output should
be between 100-500 Ohms. If the load on S port drops below 100 Ohms the detector will
behave as the S output is in short circuit status and enable the automatic output saving

RS485 serial communication output:

mode resulting with reducing signal level to 2mA.
Prosense PQ series detector has RS485 serial communication output on main board.
Connection ports are located on a different socket nearby analogue output and power input
ports. User should prepare two wire additional cables when RS485 communication used. To
use the detector with RS485 serial communication, a four-wire connection should be done
which are energy input (V +, V-) ports and RS485 (A, B) ports. Even if only the RS485
connection is to be used, the S end must have the required load resistance. If both analog
current output and RS485 serial communication terminals are to be used at the same time, a
five-wire connection must be made to connect the terminals on both sockets (V +, V-, S, A,
B). The total length of the connection line should not exceed 800 meters. The wiring for
detectors utilized with RS485 board should be done by using connection cable EIA RS485 2
core wires with section 0.22 / 0.35 mm2 and shielded. Nominal capacity between the wires
should be < 50pF/m and nominal impedance 120 Ohms.
Detectors will be wired in daisy chain (bus) mode. We recommend not using star mode
connection due to negative impact of interference. Each detector should have unique
address number in the chain. The detectors would not be recognised by control panel if
same address given to them. The address of detector can be adjusted via using configuration
PRS-UM-PQ-EN-Rev.05-18.06.2020 20