Mitsubishi MELSEC LJ71C24, User Manual

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11 DATA COMMUNICATION USING THE BIDIRECTIONAL PROTOCOL
11.1.3 Sequence program for data reception
This section explains the sequence program for data reception.
For details on the BIDIN instruction for data reception, refer to Chapter 10.
X3 Read request
Create control data from D0
G.BIDIN Un D0 D10 M0
M0 M1
(CH1)
Processing for normal completion
(stores receive data, etc.)
1)
2)
3)
4)
Reception data read
request (X3)
BIDIN instruction
BIDIN instruction complete device
BIDIN instruction complete 1
(Normal completion)
Receive data count (address: 600
H
)
Receive data(address: 601
H
to 7FF
H
)
Receive data
One scan
Response transmission Data reception
C24 ready (X1E)
BIDIN
(OFF)
m n
1) Start the host station programmable controller.
The values specified with GX Works2 are stored in the C24.
2) When data is received from the external device, Reception data read request (X3)
turns ON.
3) After the control data for the BIDIN instruction is stored in the device, the sequence
program executes the BIDIN instruction and reads the receive data.
4) When the reading of receive data is completed, a response message (ACK
message when the operation was completed normally) is sent and the device that
has completed the BIDIN instruction turns ON.