Omron 2D CODE READER User Manual page 106

FCS Calculation Method
The FCS (Frame Check Sequence) is the result of taking the XOR for each byte
between the header and footer (8 bits) and converting it to 2 characters of ASCII.
The FCS can be attached to output data to improve the reliability of communications.
Each time data is received, the PC calculates the FCS and checks it against the FCS
attached to the sent data so that the send data can be checked for errors.
FCS Setting p.47
Calculation Example for Sending FCS
Sample read data: ABCDEFG
The details of the read data and calculation method are as follows:
• Read data
Header
A B C D E F G 4 0
Read data
• Calculation method
Read data
A
Converted to
B
ASCII
C
D
E
F
G
Footer
FCS
ASCII
41
Converted to
hexadecimal
42
values
43
44
45
46
47
Appendix
Hexadecimal
0100 0001
XOR
0100 0010
XOR
0100 0011
XOR
0100 0100
XOR
0100 0101
XOR
0100 0110
XOR
0100 0111
Obtaining the
exclusive OR
0100 0000
Converted to
ASCII
FCS data: 4 0
V400-F050/250/350
User's Manual
105