Mitsubishi Electric MELSEC iQ-RJ71EN71 User Manual page 82

With nonprocedural, the subheader and data length added for procedural are not used, so the data is all
handled as valid text. The RJ71EN71 and the RnENCPU (network part) turn on the fixed buffer reception
status signal after storing the size of the received message (packet) in the receive data length storage area.
Providing a check procedure including the data length, data type code, and so on, in the message's
application data is recommended so that the application data's byte size and data type can be seen on the
receiving side.
The following figure shows the configuration of the application data when the communication procedure is set to "Fixed Buffer
(Procedure Exist)".
■Format
• When exchanging data with binary codes
Communication
request source
Communication
request destination
• When exchanging data with ASCII codes
Communication
request source
Communication
request destination
1 FUNCTIONS
80
1.5 Communications Using the Fixed Buffer
Application data area
(command message)
2 bytes
2 bytes
Data length
Subheader
setting
L H L H
Application data area
(command message)
4 bytes
4 bytes
Data length
Subheader
setting
H - - L H - - L
Maximum of
5113 words
Text
(command)
Subheader
1 byte
Maximum of
5112 words
Text
(command)
Subheader
H
2 byte
End code
1 byte
Application data area
(Response)
End code
L H L
2 byte
Application data area
(Response)