Appendix 5.3.5 Non-Verified Reception - Mitsubishi Melsec-L Series User Manual

Appendix 5.3.5 Non-verified reception

Example of format of packet from other device
1 byte
STX
Data needed by the user
Example of packet setting
1 byte
Header
App. - 54
(5) Calculating range of Check code
The following shows specification examples of the calculating range of Check
code.
Packet
element 1
Packet
Header
format
Example 1
Example 2
Example 3
Example 1: Calculating range when its start is 1 and end is n-1.
Example 2: Calculating range when its start is 2 and end is n-1.
Example 3: Calculating range when its start is 2 and end is n-2.
The following shows a usage example of Non-verified reception.
2 bytes 2 bytes
Country
Identification
code code
Set a Non-verified
reception element
2 bytes
Conversion
Non-verified reception (variable number of characters)
variable
Using a Non-verified reception element has the following advantages in the case of the
packet format shown above.
The only necessary data can be stored in the device memory of a CPU module and
buffer memory.
A single protocol (packet) can handle receive packets that includes data whose
contents vary each time.
Packet
element 2
Static data
Calculating range when specifying 1 to (n-1)
Calculating range when specifying 2 to (n-1)
Calculating range when specifying 2 to (n-2)
5 bytes 5 bytes
Manufacturer
Product code
code
Data
to be read
Variable
number of
characters
Packet Packet
element n-2 element n-1
Non-conversion
Terminator
variable
Variable
number of
characters
When the data are not needed by
the user and data contents and/or
the number of character vary
APPENDIXES
Packet
element n
Check code
1 byte
ETX
1 byte
Terminator
App. - 54