Mitsubishi Electric MELSEC iQ-R02CPU - Page 82

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1 FUNCTIONS
1.5 Communications Using the Fixed Buffer
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
• When exchanging data with ASCII codes
LH LH
2 bytes
Application data area
(command message)
2 bytes
Text
(command)
Maximum of
5113 words
End code
1 byte
1 byte
Application data area
(Response)
Communication
request destination
Data length
setting
Subheader
Subheader
Communication
request source
LH -- LH - -
HL HL
4 bytes
Application data area
(command message)
4 bytes
Text
(command)
Maximum of
5112 words
End code
2 byte
2 byte
Application data area
(Response)
Communication
request destination
Data length
setting
Subheader
Subheader
Communication
request source