SUNFAR Self-Defined Communication Protocol 70
1.2 Bus Structure and Protocol Specification
1.2.1 Bus Structure
1. Physical layer
Standard RS485 bus.
2. Transmission mode
Asynchronous serial and half-duplex transmission mode. Either main machine or
slave machine can send data at the same time, while the other one can receive data
only. The data will be sent frame by frame in message format in the process of
serial asynchronous communication.
3. Topology mode
Single main station system is compatible with 32 stations at most with one station
for main machine and the other 31 stations for slave machine. The setting range of
slave address is 0-30, while 31(1FH) is the broadcast communication address. The
slave address must be unique in the network.In fact,point-to-point mode is identifyed
as special applications case of topology mode with “One main machine and multiple
slave machines”, namely the condition of existing only one slave machine.
1.2.2 Protocol Specification
E550 series is applicable to MODBUS (please refer to Appendix II for details) and
SUNFAR custom communication protocol, which is to be described as follows:
SUNFAR custom communication protocol is a serial master-slave communication
protocol, only one device (main machine) in the network can set up protocol
(named as query/command), while the other devices (slave machine) can provide
data to response query/command of main machine or operate the corresponding
actions in line with query/command of main machine. Here, main machine refers to
personal computer (PC), industrial personal computer (IPC) or programmable logic
controller (PLC), etc., while slave machine refers to the inverter. Main machine can
separately access some slave machine and send broadcast message to all slave
machine. As for query/command for separate access sent by main machine, slave
machine should feedback one message (named as response); as for broadcast
E550 Series Universal Low-Power Inverter
