Beckhoff BC8050 - RS232 - Interface; Protocol Overview; Modbus Protocol Details

RS232 - Interface
BC8050 und BC815064 Version: 3.0.0
6 RS232 - Interface
6.1 Protocol
6.1.1 Modbus
6.1.1.1 Modbus protocol
RTU
In RTU mode the protocol starts with a pause of 3.5 characters, and finishes in the same way (illustrated in
the diagram with T1-T2-T3-T4).
The characters permitted for transmission in all fields are hexadecimal 0... 9, A..., F.
Start Slave address Function Data CRC END
t1-t2-t3-t4 1byte 1byte n Bytes 2bytes t1-t2-t3-t4
ASCII
In ASCII mode the telegram starts with a colon (":", character 0x3A) and ends with a carriage return line feed
("CRLF", characters 0x0D and 0x0A).
The characters transferred are represented in the ASCII code.
Start Slave address Function Data LRC END
1byte 0x3A 2bytes 2bytes n Bytes 2bytes 2bytes 0x0D,
0x0A
6.1.1.2 Data Frame
Description ModbusRTU (address 40-59) DEFAULT ModbusASCII (address 1-39) DEFAULT
Data bits 8 8
Stop bits 1 1
Baud rate 9600 baud 38400 baud (automatic detection)
Parity none even