Communication Protocol
113
Request format:
Protocol data unit Data length(bytes) Range
Command 1 0x06
Data Address 2 0~0xFFFF
Write Content 2 0~0xFFFF
Reply format (success):
Protocol data unit Data length(bytes) Range
Command 1 0x06
Data Address 2 0~0xFFFF
Write Content 2 0~0xFFFF
If the operation fails, the inverter will reply a message formed by failure command and
error code. The failure command is (Command＋0x80). The error code indicates the
reason of the error; see table 1.
10.5 Note:
10.5.1 Between frames, the span should not less than 3.5 bytes interval, otherwise, the
message will be discarded.
10.5.2 Be cautious to modify the parameters of PC group through communication,
otherwise may cause the communication interrupted.
10.5.3 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.
10.6 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);
}
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