TI120 Series Variable Frequency Drive
Appendix A
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7. Modbus communication example
Read the setting frequency of 1# variable frequency drive, and the setting frequency of variable
frequency drive response is 50.00Hz.
Premi-
ses
Function
code
Register
address
Number of
register
Number of
bytes in
contents
Register
content
Checksum
Request
0x01
0x03
0x0000
0x0001
No
No
0x840A
Response
0x01
0x03
No
No
0x02
0x1388
0xB512
Start the 1# variable frequency drive to rotate forward
Premises
Function
code
Register
address
Register content
Checksum
Request
0x01
0x06
0x8000
0x0001
0x61CA
Response
0x01
0x06
0x8000
0x0001
0x61CA
8. CRC16 function
unsigned int crc16(unsigned char *data,unsigned char length)
{
int i,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) )
；
// Swap high and low bytes
}
9. Establishment of communication network
There are two networking modes for variable frequency drives: single master/multiple slave mode
and single master/single slave mode. It is as shown in the following figure:
