Mitsubishi Electric MELSEC-A Series Manual page 25

1
INTRODUCTION
(f) 3-tier system 3: System configuration example using local stations/remote I/O stations
MELSECNET( II )
Coaxial loop
M
L1
L2/m
I1
I2
*1 As the transmission speed of MELSECNET/H is faster than MELSECNET(II), and as the transmission method is different,
the distance between stations and overall distance become shorter.
MELSECNET/H
Coaxial bus
1M 4
P
L3 Network 1
1N 1 1N 2/2M
S S
Network 2
r3
2N 1 2N 2
S S
System configuration precautions
1) Distance between stations: If this value
exceed the Q series specification values
when re-using the MELSECNET(II)
system cables, 3C-2V has to be changed
*1
to 5C-2V.
2) Overall distance: If this value exceeds the
Q series specification value when
MELSECNET(II) system cables are re-
used, measures (e.g. adding a repeater
unit) are required.
3) CPU: When replacing an integrated type
CPU, one new slot (32 points) is required.
4) Duplex loop: When the transmission path
4/3M 1N 3
P R S
has to be duplexed, changes to an optical
Network 3
loop system, etc. are required.
5) Composite system: As a mixture of a PLC
3R3
to PLC network and a remote I/O network
is not allowed on the Q series, the
network has to be divided into two
networks having different network Nos.
For this reason, a separate network
module for the remote master station is
required.
6) New installation: A separate coaxial cable
is required for the remote I/O stations.
*1
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