Siemens ATC5300 Manual page 15

Example of CRC calculation:
Frame = 0207h
CRC initialization
Load the first byte
Execute xor with the first
Byte of the frame
Execute 1
Carry=1, load polynominal
Execute xor with the polynominal
Execute 2
Carry=1, load polynominal
Execute xor with the polynominal
Execute 3
Execute 4
Carry=1, load polynominal
Execute xor with the polynominal
Execute 5
Execute 6
Carry=1, load polynominal
Execute xor with the polynominal
Execute 7
Execute 8
Carry=1, load polynominal
Load the second byte of the frame
Execute xor with the polynominal
Second byte of the frame
Execute 1
Carry=1, load polynominal
Execute xor with the polynominal
Execute 2
Carry=1, load polynominal
Execute xor with the polynominal
Execute 3
Carry=1, load polynominal
Execute xor with the polynominal
Execute 4
Execute 5
Carry=1, load polynominal
Execute xor with the polynominal
Execute 6
Execute 7
ATC5300
Modbus Communication Protocol, Edition 03/2011, A5E02469001-02
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right shift
nd
right shift
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1.13 CRC Calculation (CHECKSUM for RTU)
1111 1111
1111 1111
0111 1111
1010 0000
1101 1111
0110 1111
1010 0000
1100 1111
0110 0111
0011 0011
1010 0000
1001 0011
0100 1001
0010 0100
1010 0000
1000 0100
0100 0010
0010 0001
1010 0000
1000 0001
0100 0000
1010 0000
1110 0000
0111 0000
1010 0000
1101 0000
0110 1000
1010 0000
1100 1000
0110 0100
0010 0100
1010 0000
1001 0010
0100 1001
0010 0100
General Information
1111 1111
0000 0010
1111 1101
1111 1110 1
0000 0001
1111 1111
1111 1111 1
0000 0001
1111 1110
1111 1111 0
1111 1111 1
0000 0001
1111 1110
1111 1111 0
1111 1111 1
0000 0001
1111 1110
0111 1111 0
0011 1111 1
0000 0001
0000 0111
0011 1001
1001 1100 1
0000 0001
1001 1101
0100 1110 1
0000 0001
0100 1111
0010 0111 1
0000 0001
0010 0110
0001 0011 0
0000 1001 1
0000 0001
0000 1000
0000 0100 0
1000 0010 0
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