Mitsubishi Electric MELSEC iQ-R04CPU - When Receiving Data Whose Length Is an Odd Number

APPX
Appendix 10 Operation Image and Data Structure of Predefined Protocol
403
A
Ex.
When receiving data whose length is an odd number
When unit of stored data is "Lower Byte Only"
• A size double the data length is occupied. For the upper data, the Ethernet-equipped module ignores the data at sending
and adds 00H to the data at receiving.
Non-verified reception
The usage examples for a non-verified reception element is shown below.
Ex.
In the above type of packet format, the following operation can be executed by setting reception without verification.
• It is possible to store only the required information in the CPU module's device or buffer memory.
• Even if the received packet contains data that changes with each communication, it can be handled with one protocol
(packet).
03H02H 05H04H01H
0005H
0201H
0403H
0005H
+ 0
+ 1
+ 2
+ 3
External device
Byte swap
(Word) Specified device
No byte swap
Receiving
Data length storage area
Data storage area
0005H
0102H
0304H
0500H
+ 0
+ 1
+ 2
+ 3
(Word) Specified device
Data length storage area
Data storage area
Send data
Necessary information for users
Example of a packet setting
Example of a packet format of the external device
Reading data
When the information is unnecessary
for users and the data
(including the number of characters)
are variable
Non-verified reception is
set in the elements.
Product
code
Manufacturer
code
Country
code
Identification
code
5 bytes2 bytes
STX
1 byte
EXT
1 byte2 bytes 5 bytes
Non-conversion
variable
2 bytes
Static data
1 byte
Static data
2 bytes
Non-verified reception (variable number of characters)
Variable number of
characters
Variable number of characters