DEVICES, SYSTEMS AND METHODS REGARDING PLC Russian patent published in 2011 - IPC G05B19/05 

FIELD: information technology.

SUBSTANCE: system for data exchange between modules of a programmable logic controller (PLC) comprises a first module of a first chain of modules. Each adjacent pair of the first chain of modules is functionally connected in series. The first module is functionally connected to the PLC. The first module comprises a transmitting circuit and a receiving circuit. The first module is adapted to exchange data with the PLC through 8B/10B coded frames. Frames of said 8B/10B coded frames have message type field of a size which corresponds to eight bits. The value stored in said message type field servers as a feature for the contents of the data field of each of said frames. Said message type field follows the ordered sequence of fields composed of the said frame. Said ordered sequence of fields has a preamble field, a frame onset field, a destination address field, a length field and a source address field.

EFFECT: high reliability of control system owing to prevention of errors arising from failure of equipment or data transmission errors.

18 cl, 12 dwg, 4 tbl