Appendix C Examples Of Crc Calculation - Omega i-SERIES User Manual

APPENDIX C
Device address 06, read (03), starting register 0008, number of registers 0001
CRC Calculation
Function code
Load 16 bit register to all 1's
First byte is address 06
Exclusive OR
1st shift
A001
Exclusive OR
2nd shift
A001
Exclusive OR
3rd shift
A001
Exclusive OR
4th shift
5th shift
A001
Exclusive OR
6th shift
7th shift
A001
Exclusive OR
8th shift
Second byte Read 03
Exclusive OR
1st shift
2nd shift
3rd shift
A001
Exclusive OR
4th shift
5th shift
A001
Exclusive OR
6th shift
7th shift
8th shift
Third byte Starting reg. 00
Exclusive OR
1st shift
2nd shift
A001
Exclusive OR
3rd shift
A001
Exclusive OR
4th shift
Example of CRC Calculation
Two byte (16 bit) Register
HB
1111
1111
0111
1010
1101
0110
1010
1100
0110
1010
1100
0110
0011
1010
1001
0100
0010
1010
1000
0100
0100
0010
0001
0000
1010
1010
0101
0010
1010
1000
0100
0010
0001
0001
0000
0000
1010
1010
0101
1010
1111
0111
50
1111 1111
0000
1111 1111
1111 1111
0000 0000
1111 1111
1111 1111
0000 0000
1111 1111
0111 1111
0000 0000
0111 1111
0011 1111
0001 1111
0000 0000
0001 1111
1000 1111
0100 0111
0000 0000
0100 0111
0010 0011
0000
0010 0011
0001 0001
0000 1000
1000 0100
0000 0000
1000 0100
0100 0010
1010 0001
0000 0000
1010 0001
0101 0000
0010 1000
0001 0100
0000
0001 0100
1000 1010
0100 0101
0000 0000
0100 0101
0010 0010
0000 0000
0010 0010
1001 0001
Overflow
LB
1111
0110
1001
1100
0001
1101
1110
0001
1111
1111
0001
1110
1111
1111
0001
1110
1111
1111
0001
1110
1111
0011
1100
1110
1111
0111
0001
0110
0011
0001
0001
0000
1000
0100
0010
0000
0010
0001
0000
0001
0001
1000
0001
1001
0100
Bit
0
1
1
1
0
1
0
1
0
0
0
1
0
1
0
0
0
0
1
1
1