7. MODBUS
IMS01J02-E2
113
The flow chart of CRC-16
START
FFFFH
→
CRC Register
0
→
n
Shift CRC Register right 1 bit
Carry flag is
1
No
Yes
CRC Register
⊕
A001H
→
CRC Register
n + 1
→
n
No
Yes
n
>
7
No
Yes
Is message
complete ?
CRC Register
⊕
next byte of the message
→
CRC Register
END
Reverse with high-order byte and low-order byte of CRC Register.
The
⊕
symbol indicates an
exclusive OR
operation. The symbol for the number of data bits is
n
.