Bcc Calculation Example; Communications Data - Omron EasySpeed 3G3JV Series Communications Manual

CompoWay/F Communications Procedures

BCC Calculation Example

The BCC (Block Check Character) is determined by calculating the exclusive OR of the bytes from
the node number through ETX. The 8-bit result is written to the BCC byte at the end of the frame.
STX Node number
H'02 0 (H'30) 0 (H'30) 0 (H'30) 0 (H'30) 0 (H'30) 0 (H'30) 5 (H'35)
BCC = H'30 + H'30 + H'30 + H'30 + H'30 + H'30 + H'35 + H'30 + H'33 + H'03 = H'35
The result of the calculation (H'35) is written to the BCC byte.
The + symbols indicate exclusive OR operations.

Communications Data

Communications
protocol
Compoway/F 8-digit hexadecimal 2's comple-
Sub-address SID
Set values Negative
values
ment
Command text
0 (H'30) 3 (H'33)
Data
The decimal point is removed and the result is con-
verted to hexadecimal.
Example conversion: 105.0 → 1050 → H'0000041A
Chapter 2
ETX BCC
H'03 H'35
2-3