Delta 1.07 VFD-D D - Manual (Page 96)

Chapter 4 Parameter Settings|DD Series
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Step 6: Repeat step 2 to 5 for the next 8-bit byte of the command message. Continue doing this until all
bytes have been processed. The final contents of the CRC register are the CRC value. When transmitting
the CRC value in the message, the upper and lower bytes of the CRC value must be swapped, i.e. the
lower order byte will be transmitted first.
The following is an example of CRC generation using C language. The function takes two arguments:
Unsigned char* data Å a pointer to the message buffer
Unsigned char length Å the quantity of bytes in the message buffer
The function returns the CRC value as a type of unsigned integer.
Unsigned int crc_chk(unsigned char* data, unsigned char length)
{
int j;
unsigned int reg_crc=0Xffff;
while (length--){
reg_crc ^= *data++;
for(j=0;j<8;j++){
if(reg_crc & 0x01){ /* LSB(b0)=1 */
reg_crc=(reg_crc>>1) ^ 0Xa001;
}else{
reg_crc=reg_crc >>1;
}
}
}
return reg_crc; // return register CRC
Address list
Content Address Function
AC drive Parameters GGnnH
GG means parameter group, nn means parameter number, for
example, the address of Pr.04-01 is 0401H.
Drive Command 2000H Bit0~3 0: No function
1: Stop
2: Run
3: opening door is prohited
Bit4~5 00B: No function
01B: OD
10B: CD
11B: Change direction
Bit6~7 00B: 1st accel/decel
01B: 2nd accel/decel
10B: 3rd accel/decel
11B: 4th accel/decel
Bit08~11 000B: master speed