YASKAWA OYMC V1000, Programming Manual

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2.7 Message Format
YASKAWA ELECTRIC SIEP C710606 10A YASKAWA AC Drive - V1000 PRELIM. Programming Manual 271
ME
MOBUS/Mo
dbus
C
ommuni
cat
io
ns
2
Table 2.3 CRC-16 Checksum Calculation Example
■
Response Data
To be sure that the data is valid, perform a CRC-16 calculation on the response message data
as described above. Compare the result to the CRC-16 checksum that was received within
the response message. Both should match.
Description Calculation
Over-
flow
Description Calculation
Over-
flow
Initial value 1111 1111 1111 1111 Function Code 03H 0000 0011
Address 02H 0000 0010 XOR w result 1000 0001 0011 1101
XOR w initial value 1111 1111 1111 1101 Shift 1 0100 0000 1001 1110 1
Shift 1 0111 1111 1111 1110 1 XOR w A001H 1010 0000 0000 0001
XOR w A001H 1010 0000 0000 0001 XOR result 1110 0000 1001 1111
XOR result 1101 1111 1111 1111 Shift 2 0111 0000 0100 1111 1
Shift 2 0110 1111 1111 1111 1 XOR w A001H 1010 0000 0000 0001
XOR w A001H 1010 0000 0000 0001 XOR result 1101 0000 0100 1110
XOR result 1100 1111 1111 1110 Shift 3 0110 1000 0010 0111 0
Shift 3 0110 0111 1111 1111 0 Shift 4 0011 0100 0001 0011 0
Shift 4 0011 0011 1111 1111 1 XOR w A001H 1010 0000 0000 0001
XOR w A001H 1010 0000 0000 0001 XOR result 1001 0100 0001 0010
XOR result 1001 0011 1111 1110 Shift 5 0100 1010 0000 1001 0
Shift 5 0100 1001 1111 1111 0 Shift 6 0010 0101 0000 0100 1
Shift 6 0010 0100 1111 1111 1 XOR w A001H 1010 0000 0000 0001
XOR w A001H 1010 0000 0000 0001 XOR result 1000 0101 0000 0101
XOR result 1000 0100 1111 1110 Shift 7 0100 0010 1000 0010 1
Shift 7 0100 0010 0111 1111 0 XOR w A001H 1010 0000 0000 0001
Shift 8 0010 0001 0011 1111
1
XOR result 1110 0010 1000 0011
XOR w A001H 1010 0000 0000 0001 Shift 8 0111 0001 0100 0001 1
XOR result 1000 0001 0011 1110 XOR w A001H 1010 0000 0000 0001
Perform operations with next data (function
code)
XOR result 1101 0001 0100 0000
CRC-16
1101 0001 0100 0000
D140H
Continue from here with next data.