PLC Addressable Systems

These systems combine the flexibilty of a PLC (Progarmmable Logic Controller) with our high integrity building network for controlling motorised smoke dampers.

Our S90C controller is at the heart of the addressable system. It controls an XP95 network with up to 126 addresses (100 addressable units + LED drivers). When working with a PLC the S90C controller sends input data from the field to the PLC. It receives output data from the PLC and transmits this back to the field.

Mitsubishi PLCs for complex logic

The PLC (e.g. Mitsubishi FX3G), using Apollo XP95 protocol, provides a high integrity network between the control points. This has advantages in terms of power and flexibility as thiMitsubishi Keyboard display (e.g. E1022)

s system is software driven and can drive/monitor significant numbers of smoke/fire dampers. This also enables us to use standard Mitsubishi programming tools (GX Developer) to write and test the required program. Programs can be changed on site with a laptop PC and the system can be easily maintained without the need of specialist knowledge from us as programming is in ladder logic and can be modified and maintained by any engineer with Mitsubishi experience. The systems use Mitsubishi FX series PLCs for single loop systems and Q series PLCs for multi loop systems. These are very powerful industry standard controllers with a wealth of features. Mitsubishi supply a range of fully programmable keyboard displays and touchscreens for the user to interface with the system.

The key elements of a PLC addressable system are as follows:

  • Mitsubishi PLC with RS232 interface
  • Blue River S90C controller
  • Blue River Watchdog module
  • 24v dc power supply (battery backed option)
  • Panel with damper status LEDs
  • DCM damper control modules
  • Other modules as required

Maximum of 100 dampers per loop
The system will accommodate up to 100 addressable units which can be for dampers, fans, smoke detectors or other field devices. Addresses above 100 are reserved for remote indicator devices where, for example, damper status can be displayed on a remote mimic over the comms loop.

Maximum loop size of 2km
This is adequate for the largest building. On multiple buildings, individual control systems can be networked to a Building Management System using Modbus protocol.

Multiple loops for large projects
At present up to six loops can be controlled from one programmable logic controller (PLC). Very large projects use multiple PLCs.

Keyboard graphical display unit (HMI)
This unit is used to monitor or override the system for maintenance purposes and is programmable to suit the Client’s requirements and include password protection.

Fan Controls can be incorporated
Control of fans can be incorporated with the damper controls to give automatic operation in a fire, or override facilities for firemen. It is sometimes useful to interlock fans with critical dampers to prevent over pressure in ductwork.


Call us for control systems advice - 01296 613110