Data Reception From The External Device; Receiving Methods - Mitsubishi Melsec-L Series User Manual

11.1 Data Reception from the External Device

11

11.1.1 Receiving methods

CPU module
Sequence
program
3)
Read
(BIDIN
instructions)
Contents
Reception data read request
BIDIN instruction completion device
BIDIN instruction
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This section explains the data reception from the external device.
The following shows how to receive data sent from the external device using the
bidirectional protocol. Since the size of each message received is recognized using the
"data length" information contained in the message, messages of any size can be sent
from the external device.
C24
Buffer memory
Receive area
2)
Read request
(When normal)
Arbitrary data
(00 to FF )
H H
CH1/CH2
X3/XA
11 DATA COMMUNICATION USING THE BIDIRECTIONAL PROTOCOL
Arbitrary data
1)
ENQ Data length Data area
(When abnormal) (00 to FF
H
Ignored
Control Timing
BIDIN
External
device
Sum check code
)
H
2)
Error code NAK
4)
ACK
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