Overview

***also see data sheet attached, at the bottom of the page


Ceilling sensor units are round, white boxes (130mm diameter, 35mm height)  which are house for the following sensors:

  • Passive infra-red (PIR) - triggered by movement around the room 
  • Temperature - termophile sensors which monitor ambient temperature at ceilling level and surface temperature, for a better accuracy
  • Ambient light - indicates the level of light in the room
  • Humidity  -  indicates relative humidity within the room
Additional sensors that can be installed, when requested: 
  • CO2 - for air quality monitoring
  • Volatile Organic Compound (VOC) - for air quality monitoring
  • Doors/windows sensors - detects if doors/windows are open/closed
  • Extra PIRs can be installed to the side of the sensor unit (SU) so that occupancy can be detected further away - e.g along a corridor or at the other end of a larger room.



Hardware information


The Ceilling sensor unit is a translation device that uses RJ45 terminated CAT5 cables to connect Zone Gateways to sensors.

Sensor units are usually connected to sockets 6-10 of a Zone Gateway (ZG).

There is also a "suppression" circuitry on the board to dissipate any electrical noise that may have been picked up by the cable and to protect the sensors from damage due to this noise.


Wire Colour Zone Gateway SKT6-10 pin Sensors / general I/O  description Sensor fitted in standard configuration
white/orange 1 anl I/P 1, dig I/O 4 Ambient Light
orange 2 anl I/P 2, dig I/O 5 Temperature
white/green 3 0V, GND
blue 4 dig I/O 1 Passive Infra-Red (PIR)
white/blue 5 5V
green 6 dig I/O 2
white/brown 7 anl I/P 3, dig I/O 6 Humidity
brown 8 dig I/O 3

General rules for placing the sensor unit:

  • There is an A5 template with each SU which shows the orientation of the thermopile sensor with respect to the mounting screws.
  • Ideally, SU should be placed 1-2m away from an internal wall.
  • The thermopile should be pointed at an internal wall, if possible, with a non - shiny surface (i.e not glass or polished surface). Shiny surfaces alter infra-red emissions characteristics while external walls tend to be colder than the the actual room temperature, depending on wall insulation.
  • Temperature sensors should not be aimed at buried heating pipes or air ducting that will alter the wall temperature