Multiple Remote I/O Network (Process Cpu); Configuration - Mitsubishi Electric MELSEC Q Series Reference Manual

2 SYSTEM CONFIGURATION

2.2 Multiple Remote I/O Network (Process CPU)

2.2.1 Configuration

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A multiplexed remote I/O network system includes a multiplexed remote master station
and a multiplexed remote sub-master station. The multiplexed remote sub-master
station takes control of remote I/O stations when the multiplexed remote master station
fails.
Always assign station No. 0 to the multiplexed remote master station.
It is allowed to assign any of station number 1 to 64 to the multiplexed remote sub-
master station, provided that the number is not the same as that of remote I/O station.
Sixty-three remote I/O stations can be connected in an optical loop system, 31 stations
in a coaxial bus system.
POINT
Only the Process CPU is the CPU module that works as a multiplexed remote
master station and multiplexed remote sub-master station.
The CPUs other than the Process CPU do not work as a multiplexed remote
master station and multiplexed remote sub-master station.
Station No. 0
(Multiplexed remote
master station)
QnPH QJ71
CPU LP21
QJ72 I/O I/O
LP25
Station No. 64
(Remote I/O station)
Up to 63 remote I/O stations can be connected in an optical loop system.
Up to 31 stations can be connected in a coaxial bus system.
Station No. 1
(Multiplexed remote
sub-master station)
QnPH
QJ71
CPU LP21
Optical fiber cable
QJ72 I/O I/O
LP25
Station No. 4
(Remote I/O station)
MELSEC-Q
Station No. 2
(Remote I/O station)
QJ72 I/O I/O
LP25
QJ72 I/O I/O
LP25
Station No. 3
(Remote I/O station)
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