Alpha 6000S series User Manual page 204

}
else
{
crc=crc>>1 ;
crc^=0xa001 ;
}
}
ulenth-=1 ;
uptr++;
}
return(((crc&0x00FF)<<8)|((crc&0xFF00)>>8));
}
 Example of Command Application
[03H]
Reading of Single-character Command: read the single-character record content from the specified code. The record
content is divided into high 8 bits and low 8 bits and becomes part of the response content in order.
Example: read the state of frequency inverter 1
Command Content
Frequency Inverter
Address
Command Code
Start
Address
Number of
Addresses
CRC
[06H]
Single-character Writing Command: write a single character into the specified register, and save the specified data in
the specified register. The data saved should be among the order of record codes. The command content should be
arrayed in the sequence of high 8 bits and low 8 bits.
Example: start the operation of frequency inverter 1
Command Content
Frequency Inverter
Address
Command Code
Start
Address
Content of
Data
CRC
203
Normal Response Content
Frequency Inverter
01
03 Command Code
High Bit 00 Number of Data
Low Bit 20
Content
of Data
High Bit 00
Low Bit 01
CRC
High Bit 85
Low Bit C0
Notes: The number of data doubles that of address.
Normal Response Content
Frequency Inverter
01
06 Command Code
High Bit 00
Start
Address
Low Bit 01
High Bit 00
Content
of Data
Low Bit 01
High Bit 19
CRC
Low Bit CA
Appendix 4 Use of MODBUS Communication
01
Address
03
02
High Bit 00
Low Bit C1
High Bit 79
Low Bit D4
01
Address
06
High Bit 00
Low Bit 01
High Bit 00
Low Bit 01
High Bit 19
Low Bit CA
Abnormal Response Content
Frequency Inverter
01
Address
Command Code 83
Abnormality Code 03
High Bit 01
CRC
Low Bit 31
Abnormal Response Content
Frequency Inverter
01
Address
Command Code 86
Abnormality Code 00
High Bit 42
CRC
Low Bit 60