Integration of EnOcean peripherials into Domat controllers

The wireless EnOcean-based peripherials are attractive because of their easy installation and no need of batteries. They are powered using solar cells, piezoelectric elements and thermoelectric cells. Their main field of application is at installations where cabling can not be brought to sensors, window contacts or room units because of price, design, or local conditions.

EnOcean peripherials can be easily integrated into Domat controllers. The EnOcean manufacturers provide communication interfaces which map the EnOcean data to a standard protocol, typically Modbus RTU. / RS485. The Thermokon STC65-RS485 converter is a typical example. The system topology looks then somehow like this:


Peripherials which can be used for integrated room controls are room units (eg. SR04P containing a temperature sensor and setpoint correction) and solar-powered magnetic window contact SRW01. One converter can host up to 32 EnOcean devices. To commission the system, only a RS485 converter and Thermokon configuration program (free for download) are necessary. The configuration software is used to attach the sensors to the STC65-RS485 converter.

Data from the sensors are then available in a Modbus table of STC65-RS485. The STC65-RS485 converter is one of the Modbus slaves together with I/O modules, wired room controllers, communicative sensors, etc. The RS485 bus can host more than one STC65-RS485, each having different slave address, which makes it possible to increase the number of wireless sensors in the system, for example in different floors of the building.

A sample Merbon project with room unit SR04P and window contact SRW01 can be downloaded here. In the application, use only the variables which fit the sensor address. More EnOcean addresses can be added by copying of variables and changing the Modbus offset according to the STC65-RS485 Modbus table.