REXROTH EFC 3600 - Modbus Communication Example

13.2.5 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
"Inputting 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
messages 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 5000 internally)
Slave
address
Function
code
Start
address
Number of
address
Bytes
of data
Data
content
CRC code
Request 0x01 0x10 0x4000 0x0002 0x04
0x0081
0x1388
0x9F12
Response 0x01 0x10 0x4000 0x0002 N/A N/A 0x5408
● 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 0x0D04 0x0002 N/A N/A 0x8766
Response 0x01 0x03 N/A N/A 0x04
0x00E2
0x0015
0x9BCA
● 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 0x4000 N/A N/A 0x0088 0x9C6C
Response 0x01 0x06 0x4000 N/A N/A 0x0088 0x9C6C
Bosch Rexroth AG
Communication Protocols
EFC 3600
198/259
DOK-RCON03-EFC-3600***-IT03-EN-P