Modbus to Ethernet Bridge
1.1Introducing the Modbus to Ethernet Bridge
1.1.1Bridge Applications
The Modicon Modbus to Ethernet Bridge provides a means for transacting messages between Ethernet TCP/IP devices and Modbus serial devices. It supports up to eight concurrent transactions between Modbus Master and Slave devices, handling the conversion of TCP/IP and Modbus RTU/ASCII protocols transparently to the user application.
Ethernet nodes using TCP/IP can function as Modbus Masters, originating messages to the Bridge for delivery to Modbus Slave devices connected to the Bridge's Modbus port. The Bridge forwards the messages to the Slave devices using Modbus RTU or ASCII protocol and returns their responses to the Master.
Figure 1 shows a typical application in which a Bridge connects two Modbus Masters on Ethernet to several Modbus Slave serial devices.
Figure 1 Bridging Between Ethernet and Modbus
Ethernet
Bridge
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Modbus
The bridge also allows multiple Modbus networks to be linked together across an Ethernet connection. Multiple Bridges can furnish an Ethernet link between widely separated Modbus networks. This extends the message path beyond the cable lengths allowed for serial connections, and allows a Master on any Modbus network to access Slave devices on another network.
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