3

Typical Modbus Applications

In this chapter, we introduce three typical Modbus applications.

Serial master device talks to serial slave devices over the Internet

Let traditional Modbus serial devices talk over the Internet…

Many traditional serial Modbus devices can talk over RS-485, but the RS-485 network limits the maximum number of Modbus devices to 32, provided the transmission distance does not exceed 1.2 km.

By using Modbus Gateway, you can link all Serial Modbus devices over an Ethernet network. Up to 8 Modbus Gateways can be installed in the same control network, extending the coverage of a single Modbus network as far as a TCP/IP network can reach.

NPort 6110

RS-232

Modbus/RTU

 

Master device

 

 

Ethernet

 

 

 

NPort 6110

 

NPort 6110

NPort 6110

RS-232

 

RS-485

RS-485

Modbus/RTU

Slave devices

Flow meter

Loop controller

PLC

Drives

Power measurement

DCS

3-1

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Moxa Technologies 6110 user manual Typical Modbus Applications