Networks And Network Modules; Networking On All Levels - Mitsubishi MELSEC System Q Manual

Networks and Network Modules

3.7 Networks and Network Modules
3.7.1

Networking on all Levels

For complex or widely ramified applications but also for the implementation of remote inputs
and outputs or for the visualization of processes the communication between PLCs, produc-
tion control computers, operator terminals and other devices is very important.
Mitsubishi Electric offers optimal solutions based on a three-level network:
b Production level
b Control level
b Command level
Production level
A field network which links control devices, such as PLC, with remote inputs and outputs,
inverters and operator terminals is on the lowest network level in production locations.
While control devices were previously linked with sensors and drive equipment by wires on a
point-by-point basis, the field network can connect multiple sensors and drive equipment with
a single network cable, reducing the number of wires and wiring processes. When connected
with intelligent equipment such as the ID system, bar-code reader, inverter and display, the
field network allows production data control at network ends through transfer of various data,
in addition to ON/OFF data, and serves for improved maintenance efficiency by centralized
control of equipment operating statuses.
The high speed and high performance are further increased when combined with a PLC of the
MELSEC System Q while at the same time easy handling is guaranteed.
Control level
A control network which links control devices, e.g. PLC and CNC, is on the middle network level
in production sites. Designed to transfer data directly related to the operations and motions of
machinery and equipment between the control devices, the control network is required to have
excellent real-time capabilities. MELSECNET(10/H), MELSEC's control network, is highly
regarded in the market for its excellent real-time capabilities, simple network settings, highly
redundant reliability typified by duplex loop.
Command level
On the highest network level in production fields in an information network. Designed to trans-
fer production control information, quality control information, facility operating status and
other information between the PLC or facility controller and the production control computer,
the information network assumes the use of the most general-purpose Ethernet. Ethernet
accepts not only a wide variety of computers such as Windows and UNIX type personal com-
puters but also various Factory Automation equipment. The MELSEC System Q has functions
which make the best use of the Ethernet features.
In addition to the above levels networks can be divided into
b Open networks
and
b MELSEC networks.
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