Schneider Electric Modicon BM85 - Manual (Page 12)

Introducing the BM85 Bridge/Multiplexers 890 USE 103 00 2
1.1 Bridge/Multiplexers on Modbus Plus
1.1.1 The Modbus Plus Network
Modbus Plus is a local area network designed for industrial control
applications. The network enables programmable controllers, host
computers, and other devices to communicate throughout the production
areas of an industrial plant. It supports up to 64 addressable node
devices at a data transfer rate of 1 million bits per second. SingleĆcable
and dualĆcable network configurations are available.
User applications include transferring of process control and supervisory
messages. Typical networked devices include Modicon programmable
controllers that connect to the network through a direct port on the
controller or through a communications option. Network adapters
connect several types of host computer products to the network.
Multiple networks can be joined through Modicon Bridge Plus nodes.
This facilitates the design of timeĆcritical applications in which each
network employs only the devices required for the local process.
1.1.2 The BM85 on Modbus Plus
The BM85 Bridgeā/āMultiplexer operates as a Modbus Plus node and
provides four serial ports that you can configure separately for serial
devices in your application. BM85 models are available for singleĆcable
or dualĆcable Modbus Plus networks, and for support of RS232, RS485,
or Modicon Modbus serial devices.
Figure 1 shows a block diagram of two Modbus Plus networks joined
through a BP85 Bridge Plus. Serial devices communicate with the
application through the BM85 Bridgeā/āMultiplexers.