They distribute Modbus RTU communication and 24 VDC power supply. All devices are connected via RJ45 connectors to minimise wiring errors. Please read these instructions carefully and examine the equipment in order to familiarize yourself with the device before installing, operating or carrying out any maintenance work on it. For larger networks, repeaters can be used to reinforce the communication and to make longer network. Connection via RJ45 wiring system _______________________________________________________________________ 8 5. ? Information regarding installation of ATV21. Installation, adjustment, repair, and maintenance must be performed by qualified personnel.