MODBUS agreement on the remote control port
Electronic and Information Engineering Department electronics and information engineering
Abstract
Regular use of industrial PLC programmable logic controller to the multi-channel switches in the relay control, as PLC programming software for the PLC I / O port programming ability is limited, therefore joined in the design of single-chip As for the PLC I / O port expansion boards, between the bus through the RS-232C and the industrial use MODBUS on the transmission protocol used for data transmission, MODBUS agreement to join the unique CRC-16 yards and calibration Intervals to confirm the news guarantee the reliability of, and connected with the MCU control relays, designed to add low-speed TLP521 Optocoupler be effective in isolation relay control circuit, the protection of the MCU I / O ports will not be large Current impact damage, thus realizing PLC PLC remote control port switch。
