Installation guide

Introducing the Modbus Plus Network
890 USE 100 00
39
MODBUS PLUS NETWORK (UP TO 64 NODES)
BM85
BRIDGE
MULTIPLEXER
CPU
IBM PC
OR
J478
MODBUS
= MODBUS PORT
COMPATIBLE
MODEM
(SLAVE)
1 2 3 4
MODBUS NETWORK
ADDRESSES 1 ... 247
(MASTER)
ASCII, 9600 BAUD
RTU, 4800 BAUD
J478
MODBUS
MODEM
MODBUS NETWORK
ADDRESSES 1 ... 247
RTU, 4800 BAUD
RTU, 9600 BAUD
CPU
CPUCPU
Figure 23 Unique Device Addressing and Parameters
If a Modbus Plus networked controller or Modbus master device needs
to perform a lengthy command sequence to one of the Modbus
networked devices, the Bridge Multiplexer can acknowledge the
command and then handle it locally at the Modbus port. The Bridge
Multiplexer will perform a polling process with the destination device
and return a final response when the command action has been
completed. This frees the network at the port for further transactions
with other devices in the application.
1.13.4 RS232 and RS485 Configurations
Two BM85 models can be programmed by the user to support custom
RS232 or RS485 applications. Both of the models can be downloaded
with a user application image across Modbus Plus.
The user creates the application program on an IBM
PC/ATcompatible, using software development tools supplied with the
BM85. These require the use of a Borland C/C++ development
environment which must be supplied by the user.