In this paper the realization of safe communication in an unsafe environment for safety-related applications in building automation and control systems is presented. The communication system used is based on the LON technology - widely used in automation applications Ill. The requirements for the safe communication and for the network management and commissioning tools are described in the first part of this paper. The description of the hardware and software needed and the implementation of the software are the second part. At the end an outlook is made for the results after finishing the European research project SAFETYLON at the beginning of 2008.