Bosch Rexroth EFC 3600 Operating Instructions Manual page 182

Bosch Rexroth AG
Communication Protocols
CRC lower byte
CRC higher byte
End
Fig.13-20: Function 0x17_Request from RTU master
Start
Slave address
ModBus function code
Bytes of read register
Higher byte of read register 0100H
Lower byte of read register 0100H
Higher byte of read register 0101H
Lower byte of read register 0101H
CRC lower byte
CRC higher byte
End
Fig.13-21: Function 0x17_Response from RTU slave
Error code and exception code
If the slave receives the request without a communication error, but cannot handle it,
the slave will return an exception response which includes error code and exception
code informing the master of the nature of the error. The error code is formed by setting
the MSB of the function code to 1 (i.e. function code plus with 0x80, like 0x83, 0x86,
0x90, 0x97), then the exception response has a format shown below.
Slave No.
Exception codes for EFC 3600 frequency converters:
● 1=Parameter cannot be modify owing to user password locked
● 2=The function requested is not recognized by the slave, i.e. not equal to 3, 6, 8, 16
or 23
● 3=The word address indicated in the request do not exist in the slave
● 4=The word values indicated in the request are not permissible in the slave
● 5=Parameters cannot be modify in run mode
● 6=Parameters are read-only that cannot be modified
● 7=Invalid operation which is decided by the function of frequency converter
180/235
Rexroth Frequency Converter EFC 3600
38H
E3H
Transmission time for 3.5 bytes
Transmission time for 3.5 bytes
01H
17H
04H
00H
32H
00H
32H
D9H
3DH
Transmission time for 3.5 bytes
Error code Exception code
DOK-RCON03-EFC-3600***-IT01-EN-P
CRC16
Lo | Hi
(*)