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SECTION
8
Se
rial Int
erf
ac
e
(Nor
ma
l)
V530-R160
Operation Manual
SECTION 8
Communication with the Host
FCS Calculation
FCS is the result of taking the XOR for each byte between the header and footer (8 bits) and con-
verting to 2-character ASC ll code.
The FCS (Frame Check Sequence) can be attached to output data to improve communications.
Each time data is received, the host link calculates the FCS and checks it against the FCS
attached to the sent data so that the sent data can be checked for errors.
For details on an FCS check program, see
SECTION 10 Appendix FCS Check Program Exam-
ple (BASIC)
.
Refer to page 278 (SEC.10).
An FCS can only be appended if the communications mode is
Normal
.
Refer to page 206.
Example: Reading data: ABCDEFG
The details of the reading data and calculation method are as follows.
• Reading data
• Calculation
Footer
Header
A
B
C
D
E
F
G
4
0
Reading data
FCS
0100
0100
0100
0100
0100
0100
0100
0001
0010
0011
0100
0101
0110
0111
Reading data
On conversion
to ASCII code:
A
B
C
D
E
F
G
ASCII code
41
42
43
44
45
46
47
On conversion
to hexadecimal
notation:
Hexadecimal
notation
XOR
XOR
XOR
XOR
XOR
XOR
0100 0000
On obtaining the exclusive
logical sum:
On conversion
to ASCII code:
FCS data: 4 0