4 FUNCTIONS
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(c)
Change of state
Change of state is a communication method by which the following steps 1)
and 2) are performed to each slave node by changes in I/O data.
No data transmission is performed unless any change is made in I/O data,
1) When output data of the master node changes, the master node
sends the data to the slave node.
2) When input data of the slave node changes, the slave node sends
the data to the master node.
The change-of-state communication does not have a concept of
communication cycle.
Master node
1)
Slave node
2)
MELSEC-Q
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