LSIS XGL-C22A, User Manual, Page: 184 / 299

Chapter 9 User-defined Communication
9-3
When setting BCC, in case of general method, the user need not set BCC setting range and indication method and in case
of dedicated method, the user should set BCC setting range and indication method.
Item Contents
Start
position
Start area Determines where BCC calculation starts from among HEAD/BODY/TAIL
Segment
Determines segment location to start BCC calculation in HEAD/BODY/TAIL. 0 means first segment will be
included in the BCC calculation
End
position
Before BCC Included from start position to before BCC
End of area Included from start position to end of designated area
Settings Included from start position to designated area segment
ASCII conversion Converts result value, its size will be double
Initial value 0 Designates BCC initial value as 0. If there is no designation, initial value is FF
H.
9.2.3 Structure of BODY
Input type of segment which composes BODY is different according to reception and transmission.
In case of transmission, they are divided into string constant, numerical constant and fix sized variable. Meaning of string
constant and numerical constant is same with HEAD’s.
(1) Variable sized variable (in RX frame)
Part where size and contents changes are defined as variable sized variable. Variable sized variable can be set in the
BODY and after variable sized variable, the user can’t add segment. When using variable sized variable, there should be
one among HEAD, TAIL. If the user registers variable sized variable without HEAD, TAIL, when receiving frame, there
may be error according to communication status. For reliability of communication, register one among HEAD, TAIL. (In
case of Variable sized variable of TX frame, the size is designated in P2P Block setting, so the function and characteristic
is same with Fix sized variable of RX frame.)
(2) Fix sized variable (in RX frame)
Frame part where size is fixed but contents changes are defined as Fix sized variable. It can be set in the BODY. In case of
Fix sized variable, the user can register up to 4.
TRX frame standard for user - defined communication of XGT Cnet I/F module is as follows.
Group Frame Segment Reference
TX
frame
HEAD
Numerical constant Max. 10 byte
String constant Max. 10 byte
TAIL
Numerical constant Max. 10 byte
String constant Max. 10 byte
BCC Only one BCC applicable
BODY
Numerical constant Max. 10 byte
String constant Max. 10 byte
Variable sized variable Available up to 4
RX
frame
HEAD
Numerical constant Max. 10 byte
String constant Max. 10 byte
TAIL
Numerical constant Max. 10 byte
String constant Max. 10 byte
BCC Only one BCC applicable
BODY
Numerical constant Max. 10 byte
String constant Max. 10 byte
Fix sized variable
Available up to 4
Fix sized variable 3, variable sized variable 1 are
available
Variable sized variable
Only one variable sized variable available
After variable sized variable, adding segment is
impossible