App 3-1
Appendix 3 BDI50 Communication protocol
A3.1 Modbus communication protocol
1. Communication Data Frame
BDI50 series inverter can be controlled by a PC or other controller with the Communication
protocol, Modbus ASCII Mode & Mode RTU, RS485 or RS232. Frame length maximum 80
bytes.
1.1 Hardware installation
(PLC / HMI
Slave BDI50
Slave BDI50
Slave BDI50
Slave BDI50
RS-485
A B A B A B A B
Response
Request
** The network is terminated at each end with an external terminating resistor (120Ω,1/4w)**
1.2 Data format ASCII MODE
Communication Address(Station):
Function Code (command):
Command Start byte:
4-digit ASCII Code
The length of the command:
4-digit ASCII Code
LRC Check Code:
LRC Check Lo
End Byte :
END Hi = CR(0DH), END Lo= LF(0AH)
END Lo