Bosch Rexroth EFC 3600 Operating Instructions Manual page 177

DOK-RCON03-EFC-3600***-IT01-EN-P
Rexroth Frequency Converter EFC 3600
Address of
Slave
1 st
0x10
No.
Hi | Lo
Fig.13-8: Function 16_Request from the master
Slave No. 0x10
Fig.13-9: Function 16_Response from the slave
Address of 1
Slave
0x17
word to be read
No.
Number of
Number of bytes
words
to be written
to be written
Hi | Lo
Fig.13-10: Function 23_Request from the master
Slave No. 0x17
Fig.13-11: Function 23_Response from the slave
Function codes example
● Function 0x03: Read N register words, range: 1 ~ 16.
Example: It is necessary to read 2 continuous words starting from communication
register 0100H of the slave frequency converter addressed at 01H. The frame struc‐
ture is described in the tables below.
Start
Slave address
ModBus function code
Higher byte of start address
Number
word
of words
Hi | Lo
Address of 1 st
Hi | Lo
Number of words
st
Hi | Lo
Value of 1
to be written
Number of
bytes read
Number
1 word
st
of bytes
value
Hi | Lo
Number of words
word
Hi | Lo
to be read
Hi | Lo
Value of last word
st word
–
Hi | Lo
1 st word
–
value read
Hi | Lo
Transmission time for 3.5 bytes
01H
03H
01H
Bosch Rexroth AG
Communication Protocols
Last word
CRC16
value
–
Hi | Lo Lo | Hi
CRC16
Lo | Hi
Address of 1 word
st
to be written
Hi | Lo
CRC16
to be written
Hi | Lo Lo | Hi
Last word
CRC16
value read
Hi | Lo Lo | Hi
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