User`s manual

FX communication
Computer link 7
7-4
7.3 How to Read a Control Protocol Diagram
1 ) When the computer reads data from the programmable controller
(computer
←
programmable controller)
a ) Areas A and C indicate transmission from the computer to the programmable controller.
b ) Area B denotes transmission from the programmable controller to the computer.
c ) The computer program is created so that the data is transmitted in the order read from left
to right, and the protocol determines that the data is sent in the sequence A, B, C.
(Example: In area A, ENQ is transmitted followed by all other data, starting to the right, after
the ENQ.)
2 ) When writing data from the computer into the programmable controller
(computer
→
programmable controller)
a ) Areas A indicates transmission from the computer to the programmable controller.
b ) Area B denotes transmission from the programmable controller to the computer.
c ) The computer program is created so that the data is transmitted in the order read from left
to right, and the protocol determines that the data is sent in the sequence A, B.
(Example: In area A, ENQ is transmitted followed by all other data, starting to the right, after
the ENQ.)
Computer
Programmable
controller
Data
Data
S
T
X
Data
A
C
K
B
E
N
Q
A
C
Data
Data
Computer
Programmable
controller
A
C
K
E
N
Q
A
B