Mitsubishi Electric MELSEC-A Series Manual page 36

1
INTRODUCTION
(b) Coaxial bus system
• When the master station is replaced
MELSECNET/10
Coaxial bus
1M
R
Network 1
1R1
• When the module is replaced gradually
MELSECNET/10
Coaxial bus
1M
R
(An)
Network 1
1R1 1R2
(An) (An)
(c) Coaxial loop system
MELSECNET/10
Coaxial loop
1M
1R1 Network 1 1R3
1R2
1
- 19
MELSECNET/H
Coaxial bus
1M
R
1R2 1R3 1R1
MELSECNET/10
Coaxial bus
1M
R
(An)
1R3 1R1
(An) (An)
MELSECNET/H
Coaxial bus
R
1M
R
1R1
System configuration precautions
The module configuration example when
the master station is replaced
1M
Network 1 R
1R1 to 1R3: QJ72BR15 (MELSECNET/H
mode)
1R2 1R3
System configuration precautions
The example when the module is replaced
gradually
(1R3 is replaced with the Q series module)
Network 1
1R3: A(1S)J72(Q)BR15  QJ72BR15
1R2 1R3
(MELSECNET/10 mode)
(An) (Qn)
System configuration precautions
• The Q series modules do not support
the coaxial loop system. When the
existing system is replaced with the
coaxial loop system, replace all remote
I/O stations.
• Overall distance: If this value exceeds
the Q series specification value when
the MELSECNET/10 system cables are
re-used, measures (e.g. adding a
Network 1
repeater unit) are required.
• Number of stations: When 64 modules
1R2 1R3
are connected, measures (e.g. dividing
into two or three networks of 32 modules
or less having a different network No.)
are required.
• Duplex loop: When the transmission
path has to be duplexed, changes to an
optical loop system, etc. are required.
: QCPU + QJ71BR11