An Industrial Realtime Data Transmission Gateway by Modbus Serial Bridge Protocols Using Transparent Transmit Serial Over TCP Technique

Traditional Industrial Gateways are complex and expensive part of the real-time data transfer that supports multiple network which may not be required for process industries since Modbus protocols are used predominantly. Through the use of the proposed Modbus Serial Bridge (MSB), which combines the Modbus RTU and Modbus TCP protocols, it is possible to upgrade the existing Modbus Serial devices to support Modbus TCP for sending and receiving data. Receiving data is then directly connected to remote hosts or the cloud via IP to an existing Modbus client via the TCP/IP Ethernet gateway. The network is managed by a 32-Bit MCU-based MSB, and an RS-232/RS-422/485 device that supports Modbus/TCP master and slave is connected to Ethernet and the Internet via a Serial-to-Ethernet device, which serves as an affordable Modbus/TCP to RTU/ASCII bridge. Software codes and functional blocks are developed to maintain the states, sending receiving packets, protocol conversions, slave ID, function ID validation, writing circular buffer, CRC and IP management and also to achieve the faster transparent transmissions in bidirectional way and act as the Modbus gateway. Sample data transfer is done with designed MSB results are verified with Modpoll and Modscan software and then presented.