
UPS2000-(6 kVA-20 kVA)
Modbus Protocol Development Guide
1 Communication Protocol
Issue 02 (2016-03-10)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
7
Figure 1-5
Connecting cables for the Modbus card
shows the RJ45 port pins. For port pin definitions and cable connections, see
Figure 1-6
RJ45 ports
Table 1-3
Pins on an RJ45 port
Pin
No.
Signal
Corresponding Signal of RS232-RS485
Adapter
Two-wire system Four-wire system
1
Four-wire system: RS485 TX+
Two-wire system: A
A
RS485 RX+
2
Four-wire system: RS485 TX–
Two-wire system: B
B
RS485 RX-
3
None
N/A
N/A
4
Four-wire system: RS485 RX+
N/A
RS485 TX+
5
Four-wire system: RS485 RX–
N/A
RS485 TX–
6
GND
N/A
N/A