PLC PLC Ethernet based Backplane and Module for Programmable Logic Controller

摘要

The present invention relates to a PLC back plane based on an Ethernet switch and includes a plurality of slots including a power terminal, a control signal terminal, a first Ethernet signal terminal, and a second Ethernet signal terminal, A control signal line commonly connected to control signal terminals of each slot, a second Ethernet signal line for forming a return path, and a path selector provided corresponding to one or more slots. The path selection unit selectively connects the second Ethernet signal terminal of the slot to one of the first Ethernet signal terminal and the second Ethernet signal line of the next slot according to the control signal. The problems of parallel bus signal interference, signal racing, reflected wave, and limited bus access control in the backplane based on the conventional parallel bus can be solved, and the quality and application method of the backplane can be improved.