14.3.5 Modbus Communication Example
One slave address is 01H. The frequency setting of the frequency converter has
been set to 'Given by communication' and the RUN command source is set to 'In-
putting commands by communication'. It is required for the motor connected to
the frequency converter to run with 50 Hz (forward rotation). The operation can
be achieved with function 0x10 (function 16) of the Modbus protocol. The mes-
sages of the requests from the master and responses from the slave are shown
in table below:
●
Example 1: Start 01# frequency converter for forward rotation at frequency of
50.00 Hz (represented by 5,000 internally)
Slave
address
Function
code
Start
address
Number of
address
Bytes
of data
Data
content
CRC code
Request
0x01
0x10
0x7F00
0x0002
0x04
0x0081
0x1388
0x8AE3
Response
0x01
0x10
0x7F00
0x0002
N/A
N/A
0x581C
●
Example 2: Read the output frequency of 01# frequency converter and output
velocity
Slave
address
Function
code
Start
address
Number of
address
Bytes
of data
Data
content
CRC code
Request
0x01
0x03
0x1000
0x0002
N/A
N/A
C0CB
Response
0x01
0x03
N/A
N/A
0x04
0x1388
0x05DC
0x7C54
●
Example 3: Stop 01# frequency converter according to the stopping mode
with the function code
Slave
address
Function
code
Start
address
Number of
address
Bytes
of data
Data
content
CRC code
Request
0x01
0x06
0x7F00
N/A
N/A
0x0088
0x9078
Response
0x01
0x06
0x7F00
N/A
N/A
0x0088
0x9078
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