1.1 Cyclic Transmission; Data Flow And Link Device Assignment; Chapter 1 Functions - Mitsubishi Electric MELSEC iQ-RJ71EN71 User Manual

1
FUNCTIONS
1.1
Cyclic Transmission
This function allows data to be periodically exchanged among stations on the same network using link devices.

Data flow and link device assignment

Master station and slave stations (except for local stations)
One-to-one communication is possible between the master and slave stations. The status data of the link devices (RY, RWw)
of the master station is output to the external device of the slave station, and the input status information from the external
device of the slave station is stored in the link devices (RX, RWr) of the master station.
CPU module
Device
Ø
Sequence
scan
Link
refresh
Device
Ó
Sequence
scan
Link
refresh
M0
Ò
Y
• Output from the master station
 The device of the CPU module turns on.
 The status data of the device of the CPU module are stored in the link devices (RY, RWw) of the master station by link refresh.
 The status data of the link devices (RY, RWw) of the master station are stored in the link devices (RY, RWw) of each slave station by link scan.
 The status data of the link devices (RY, RWw) of the slave station are output to the external device.
• Input from the slave station
 The status data of the external device are stored in the link devices (RX, RWr) of the slave station.
 The status data of the link devices (RX, RWr) of the slave station are stored in the link devices (RX, RWr) of the master station by link scan.
 The status data of the link devices (RX, RWr) of the master station are stored in the devices of the CPU module by link refresh.
1 FUNCTIONS
16

1.1 Cyclic Transmission

Station No.0
Master
station
RX, RWr
Station
×
No.1
Station
×
No.2
Station
×
No.3
Link
scan
RY, RWw
Station
Ô
No.1
Station
Ô
No.2
Station
Ô
No.3
Station No.1 Station No.2
Slave station Slave station
RX, RWr
Station No.1
RX, RWr
Station No.2
RY, RWw
Station No.1
RY, RWw
Station No.2
Area where data is sent to
other stations
Station No.3
Slave station
Ö
RX, RWr External device
Station No.3
Õ
External device
RY, RWw
Station No.3