Adtech iMASTER – A1 Series - Page 168

A1-User’s Manual
１６４
5) 16 bit CRC generation
The step of CRC generation is as follows:
1. All of 16-bit Parameter is 1.0xffff
2. The exclusive OR of 16-bit Parameter and 8-bit Parameter.
3. Shift right side 1bit 16-bit Parameter
4. If the result of step 3 is 1, exclusive OR 16-bit Parameter and 0xa001.
5. Execute 8 times step 3 and step 4.
6. Execute step 2∼6 until data completion.
7. Exchange the step 6 result of higher 8bit and lower 8bit.
Ex) the case of d01 output frequency reading.
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Communication
Number
Command
Parameter
Parameter number
0x01
0x03
0x01
0x01
0x00
0x01
The sequence of addition Byte (01x01)
16-BIT PARAMETER MSB Flag
(Exclusive OR) 1111 1111 1111 1111
01 0000 0001
1111 1111 1111 1110
Shift 1 0111 1111 1111 1111
Shift 2 0011 1111 1111 1111 1
Polynomial 1010 0000 0000 0001
1001 1111 1111 1110
Shift 3 0100 1111 1111 1111
Shift 4 0010 0111 1111 1111 1
Polynomial 1010 0000 0000 0001
1000 0111 1111 1110
Shift 5 0100 0011 1111 1111
Shift 6 0010 0001 1111 1111 1
Polynomial 1010 0000 0000 0001
1000 0001 1111 1110
Shift 7 0100 0000 1111 1111
Shift 8 0010 0000 0111 1111 1
Polynomial 1010 0000 0000 0001
1000 0000 0111 1110