Mitsubishi Electric MELSEC iQ-R Series User Manual page 526

When communication type is "Send & Receive"
A packet is sent once, and the status changes to the data receive wait stat after the transmission completes normally. Then,
data is received from the target device, and the process completes when the received data matches the receive packet and
the receiving process is performed.
C24
Predefined receive packet
Header Station
No. 2
Up to 16 receive packet
can be specified
The operation image of "Send & receive" is as follows.
■Normal completion
CPU
Execute dedicated instruction
module
(G(P).CPRTCL)
Completion device
Status display device
at completion
C24
Target device
APPENDICES APPENDIX
524
Appendix 5 Operation Image and Data Structure of Predefined Protocol
Terminator
Verification match
Verification match
(Receive
buffer clear)
* Only if it is specified
Transmitted data
Command Station
Data
No. 2
Receive data 1
Header Station
No. 1
Receive data 2
Header Station
No. 2
Start waiting for receive data
Send packet
Send packet
Header
Target
device
Store verification-matched
receive packet number
(1 to 16)
OFF at normal
completion
Receive packet
Verification match
Receive packet