The STC-BACnet IP 902 MHz EnOcean Radio Transceiver is Thermokon’s new and dynamic bi-directional gateway for EnOcean-based sensors, actuators, controllers, and control systems with BACnet IP interface. Configuration and commissioning is done using the EasySens AirConfig Software tool.
Transmitting Frequency and Measuring Principles: Sensors send events and/or time controlled telegrams to the receiver.
A: Event Controlled: By operation of controls, for example, you press the learn button of the device, the internal microprocessor is woken up and sent a telegram. Whish data contained in the telegram is in the EEP (EnOcean equipment profile) defined (http://www.enoceanalliance.org/eep/).
B: Time Controlled: The sensor wake up at regular intervals (T_wake up) and send the measured values. Provided that the measured values from the last transmission have significantly changed, the current readings are sent. With almost unchanged measured values the sensor goes to sleep-mode without a telegram to send. Is repeatedly sent no unchanged measurements the sensor sends a telegram after a specified number of wake-up-cycles. A telegram always includes all information (measured data, charging voltage of energy storage, etcetra).
Information about EasySens (Radio)Transmission Range:
As the radio signals are electromagnetic waves, the signal is damped on its way from the sender to the receiver. That is to say, the field strength is removed inversely proportional to the square of the distance between sender and receiver (E,H~1/r²), at twice the distance, only ¼ of the field strength is still present. Beside these natural transmission range limits, further interferences have to be considered: Metallic parts, e.g. reinforcements in walls, metallized foils of thermal insulations or metallized heat-absorbing glass, are reflecting electromagnetic waves. Thus, a so called radio shadow is built up behind these parts. Radio waves can penetrate walls; however, signal dampening is increased versus transmitting within the free field.
Penetration of radio signals (Material Penetration)
Wood, gypsum, glass uncoated 90..100%
Brick, pressboard 65.. 95%
Reinforced concrete 10.. 90%
Metal, aluminium pasting 0.. 10%
This means that the building material used in a building is of paramount importance for the evaluation of the transmitting range.
For an evaluation of the environment, please see guide values listed below:
Radio path Range/penetration
Visual contacts Typ. 98 ft. range in passages, corridors, up to 328 ft. in halls
Plasterboard walls/wood Typ. 98 ft. range through max. 5 walls
Brick wall/Gas concrete Typ. 66 ft. range through max. 3 walls
Reinforced concrete/-ceilings Typ. 33 ft. range through max. 1 ceiling
Supply blocks and lift shafts should be seen as a compartmentalization
In addition, the angle with which the signal sent arrives at the wall is also important. Depending on the angle, the effective wall strength and thus the damping attenuation of the signal changes. If possible, the signals should run vertically through the wall. Recesses should be avoided.
Ken Smyers (Co-Founder and Co-Chairman of the CTA Awards)