User`s guide

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1.0 Serial MODBUS Gateway Overview
The Monnit Serial MODBUS Gateway (SMG) acts as a data
concentrator for Monnit wireless sensor networks. This device
allows you to connect up to 50 wireless sensing devices, per
gateway, to your existing serial MODBUS RS-232C and RS-485
sensing and control infrastructures.
Monnit has recognized the importance of using open standards
like MODBUS, allowing Monnit wireless sensors to be used in
the majority of industrial applications. MODBUS is often used to
connect a supervisory computer with a remote terminal unit
(RTU) in supervisory control and data acquisition (SCADA)
systems. MODBUS allows for communication between many
devices connected to the same wired network. Therefore, Monnit
SMG’s allow for seemingly unlimited wireless expansion of a
traditional wired network.
A system incorporating a Monnit SMG consists of the following:

MODBUS Master – PLC, SCADA, etc.

Existing RS-232C or RS-485 Infrastructure.

Monnit Serial MODBUS Gateway (SMG).

Monnit Wireless Sensors
For information about the MODBUS TCP interface,
please refer to documentation regarding the Ethernet Gateway
v3.0.