ETHERNET BASED BACKPLANE AND MODULE FOR PROGRAMMABLE LOGIC CONTROLLER

摘要

The present invention relates to a programmable logic controller (PLC) backplane based on an Ethernet switch, which comprises: a plurality of slots which include a power source terminal, a control signal terminal, a first Ethernet signal terminal, and a second Ethernet signal terminal; a power source line commonly supplying power to the power source terminal of each slot; a control signal line commonly connected to the control signal terminal of each slot; a second Ethernet signal line for forming a feedback path; and a path selection unit configured to correspond to the slots. The path selection unit selectively connects the second Ethernet signal terminal of a corresponding slot to any one from the first Ethernet signal terminal and the second Ethernet signal line of a next slot according to a control signal. Accordingly, the quality and an application method of the backplane can be improved by solving problems of parallel bus signal interference, signal racing, reflected waves, limited bus access control, etc. which occur in the backplane based on a conventional parallel bus.