Mitsubishi Electric FX5 User Manual page 232

CRC error checking procedure
Shift 1
Generator polynomial
Exclusive OR (XOR)
Shift 2
Generator polynomial
Exclusive OR (XOR)
Shift 3
Generator polynomial
Exclusive OR (XOR)
Shift 4
Shift 5
Generator polynomial
Exclusive OR (XOR)
Shift 6
Shift 7
Shift 8
CRC value
Check code calculation range
The following shows specification examples of the check code calculation code.
Packet
element 1
Packet format Header
Example 1
Example 2
Example 3
Example 1: Calculating range when 1 and n-1 are specified as the start and the end respectively.
Example 2: Calculating range when 2 and n-1 are specified as the start and the end respectively.
Example 3: Calculating range when 2 and n-2 are specified as the start and the end respectively.
APPENDIX
230
Appendix 2 Operation Image and Data Structure of Predefined Protocol
16-bit register (MSB)
0100 0000
1010 0000
1110 0000
0111 0000
1010 0000
1101 0000
0110 1000
1010 0000
1100 1000
0110 0100
0011 0010
1010 0000
1001 0010
0100 1001
0010 0100
0001 0010
12H
Packet
element 2
Static data
Calculating range when specifying 1 to (n-1)
Calculating range when specifying 2 to (n-1)
Calculating range when specifying 2 to (n-2)
Flag
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
0100 0001 0
41H
Packet Packet
element n-2 element n-1
Non-conversion
Terminator
variable
Calculating
procedure
7
8
Packet
element n
Check code