INVT CHV160A Series - CRC Check; Example

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TP.Bắc Ninh
 In the same frame, if the span between two .near bytes more than 1.5 bytes
interval, the behind bytes will be assumed as the start of next message so that
communication will failure.
9 . 6 CRC Check
For higher speed, CRC-16 uses tables. The following are C language source code for
CRC-16.
unsigned int crc_cal_value(unsigned char *data_value,unsigned char
data_length)
{
int i;
unsigned int crc_value=0xffff;
while(data_length--)
{
crc_value^=*data_value++;
for(i=0;i<8;i++)
{
if(crc_value&0x0001)crc_value=(crc_value>>1)^0xa001;
else crc_value=crc_value>>1;
}
}
return(crc_value);
}
9 . 7 Exam pl e
9.7.1 RTU mode, read 2 data from 0004H
The request command is: