Implementation Aspects for KNX PL Devices
Standardized BCUs and modules (PIM) are also available for KNX PL (110) similar to Twisted Pair.
BCU "Bus coupling units"
These are system devices which include the KNX coupling circuitry, a microprocessor and are delivered with housing. The device developer only needs to develop the application module, the application hardware and software.
PIM "Powerline Interface Modules"
They are basically built up of the low voltage part of the BCU. PIMs are modules that are soldered to the circuit board together with other network coupling parts.
ASIC with Communication Stack
An ASIC for PL110 is responsible for sending and receiving bits. To build a KNX device based on such an ASIC a KNX stack for Powerline (communication software) is necessary. A communication stack contains interfaces for the programming of the application.
What is the right solution?
In case of flush-wall mounted devices and lower production quantities, BCUs are best suited to develop cost effective devices. For medium production quantities, PIMs are recommended - a circuit diagram is available. The development of PL devices with ASIC and communication stack requires larger investments as compared to BCUs and PIMs and is therefore generally only suited for high production quantities.