Implementation Aspects for KNX RF devices
The development of KNX RF devices does not require special KNX components. To reduce development time and - costs however, it can be useful to integrate ready-made RF Modules - usually in case of low production quantities. A KNX RF node basically consists of the following elements:
For KNX RF no dedicated chip is necessary. Today there are a couple of chips available which can be used to implement a KNX RF node. For unidirectional devices, low cost transmit-only chips are available.
The transceiver builds together with a couple of passive components the RF circuit. Based on the reference design of the chip manufacturer, a circuit can be designed and optimized to the KNX RF requirements.
The core of any KNX device is a microcontroller which handles the communication as well as the application task. For RF one of the most important requirements is low power consumption. The interface logic to connect the transceiver should be present in most of today’s controllers.
The KNX standard defines a complex protocol which leads to a high implementation and certification effort. The communication stack is the system software for a KNX RF device. It controls the transceiver and handles complete communication, including the configuration procedure. The communication stack provides an interface (API) for application development.