Veichi AC90 Manual page 185

AC90 TENSION CONTROL FREQUENCY INVERTER MANUAL
can begin.
There is at lowest
3.5 bytes vacancy at
beginning
Command code and communication data description
●
For example：The frequency inverter whose slave machine address is 01H, memory initial address is 2100H [(C-00]),
read continuously 3 words, then the structure of that frame is described as follows:
RTU host machine command information
START
Slave machine address
Command code
Start address high-order
Start address low-order
Data number high-order
Data number low-order
CRC CHK low-order
CRC CHK high-order
END
RTU Slave machine responding information（normal）
START
Slave machine address
Command code
Byte number low-order
Data address 2100H high-order
Data address 2100H low-order
Data address 2101H high-order
Data address 2101H low-order
Data address 2102H high-order
Data address 21021H low-order
CRC CHK low-order
CRC CHK high-order
END
Slave machine responding information（abnormal）
START
Slave machine address
Command code
Error code
CRC CHK low-order
CRC CHK high-order
END
RTU DATA FRAME FORMAT
MODBUS MESSAGE
slave machine
function
address
code
Transmission time of 3.5 bytes
01H
03H
21H
00H
00H
03H
0FH
F7H
Transmission time of 3.5 bytes
BASIC OPERATION AND TRIAL RUN
checking
data
Transmission time of 3.5 bytes
01H
03H
06H
13H
88H
00H
00H
00H
00H
90H
A6H
Transmission time of 3.5 bytes
Transmission time of 3.5 bytes
01H
03H
04H
21H
33H
Transmission time of 3.5 bytes
180
There is at lowest
3.5 bytes vacancy at
ending