Panasonic HL-D3 Series, User Manual

Page: 256 / 305

Chapter 5 External communication control
5-37
5

Format of abnormal response
The abnormal response communication data is common in all commands.

BCC
BCC is the code for horizontal parity check to improve the reliability of
communication data. The exclusive logical sum from the header ( ) to
the final character of communication data is calculated and resultant 8-bit
data is converted to 2-character ASCII code. The controller checks
whether the exclusive logical sum of received communication data (from
the header to the final character of communication data) is consistent with
the value transmitted by the personal computer. The difference in BCC
between at transmission and at receipt indicates that an error occurred in
the communication data during communication.
To omit BCC calculation, enter
(2Ah
，
2Ah) to BCC. In this case, the
BCC in the response data is (2Ah
，
2Ah), too.
Creation example of BCC
＊ ＊
＊ ＊
%
% E E
!
Header Error Code BCC
CR
2-character
% E E # R M B C E 6
CR
%
E
E
#
R
M
B
C
End character of
communication data
Header
Exclusive logical sum (XOR) of received
communication data is calculated.
ASCII
H25
H45
H45
H23
H52
H4D
H42
H43
H 18
1 8
BCC
(H)
BCC
(L)
(H31) (H38)