Sungrow SG250HX-US, User Manual

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The port RS485_1 is used to connect Logger, so as to implement data exchange with PC or
other monitoring devices.
The port RS485_2 is used to connect communication device of the tracking system, so as to
implement data exchange with the tracking system. Terminal definitions of the two ports are
as follows:
table 5-5 RS485_1 port terminal definition
No. Definition
A1
RS485 A IN, RS485A differential
B1
RS485 B IN, RS485B differential signal-
A1
RS485 A OUT, RS485A differential
B1
RS485 B OUT, RS485B differential signal-
table 5-6 RS485_2 port terminal definition
No. Definition
B2
RS485 B OUT, RS485B differential signal-
A2
RS485 A OUT, RS485A differential
B2
RS485 B IN, RS485B differential signal-
A2
RS485 A IN, RS485A differential
When multiple inverters (≥15) are connected in a daisy chain, a dip switch can be used to
connect a resistor of 120Ω in parallel between A and B pins to ensure communication quality.
The silk print of the Dip switch corresponding to the RS485_1 port is SW2.
The silk print of the DIP switch corresponding to the RS485_2 port is SW1.
5.10.2 RS485 Communication System
Single-inverter Communication System
In case of a single inverter, communication cable connection requires only one RS485 cable.
5 Electrical Connection User Manual