INVT CHF100A-004G-2, Operation Manual

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CHF100A series high performance universal inverter
.111.
9.5 Note:
9.5.1 Between frames, the span should not less than 3.5 bytes interval, otherwise, the
message will be discarded.
9.5.2 Be cautious to modify the parameters of PC group through communication,
otherwise may cause the communication interrupted.
9.5.3 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.
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^=*dat+;
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 Example
RTU mode, read 2 data from 0004H
The request command is:
START T1-T2-T3-T4 (transmission time of 3.5 bytes)
Node address 01H
Command 03H