hpmont HD20 Series - Page 178

Shenzhen Hpmont Technology Co., Ltd Appendix B Communication Protocol
HD20 Series Inverters User Manual －163－
0xC07B,0x807A,0x41BA,0x01BE,0xC07E,0x807F,0x41BF,0x007D,0xC1BD,0x81BC,0x407C,
0x01B4,0xC074,0x8075,0x41B5,0x0077,0xC1B7,0x81B6,0x4076,0x0072,0xC1B2,0x81B3,
0x4073,0x01B1,0xC071,0x8070,0x41B0,0x0050,0xC190,0x8191,0x4051,0x0193,0xC053,
0x8052,0x4192,0x0196,0xC056,0x8057,0x4197,0x0055,0xC195,0x8194,0x4054,0x019C,
0xC05C,0x805D,0x419D,0x005F,0xC19F,0x819E,0x405E,0x005A,0xC19A,0x819B,0x405B,
0x0199,0xC059,0x8058,0x4198,0x0188,0xC048,0x8049,0x4189,0x004B,0xC18B,0x818A,
0x404A,0x004E,0xC18E,0x818F,0x404F,0x018D,0xC04D,0x804C,0x418C,0x0044,0xC184,
0x8185,0x4045,0x0187,0xC047,0x8046,0x4186,0x0182,0xC042,0x8043,0x4183,0x0041,
0xC181,0x8180,0x4040}
It takes a comparatively long time to online calculate the CRC checksum of each byte, but it will
save program space. Code of online calculating CRC is shown below:
unsigned int crc_check(unsigned char *data,unsigned char length)
{
int i;
unsigned crc_result=0xffff;
while(length--)
{
crc_result^=*data++;
for(i=0;i<8;i++)
{
if(crc_result&0x01)
crc_result=(crc_result>>1)^0xa001;
else
crc_result=crc_result>>1;
}
}
return (crc_result=((crc_result&0xff)<<8)|(crc_result>>8));
}
B