Huawei UPS2000 - Communication Mode at the Physical Layer

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.
8
Pin
No.
Signal
Corresponding Signal of RS232-RS485
Adapter
Two-wire system
Four-wire system
7
None
N/A
N/A
8
None
N/A
N/A
----End
1.4 Communication Mode at the Physical Layer
After the slave nodes are powered on or reset, and run steadily, the slave nodes respond to the
read or write commands. When the slave nodes receive the relevant command, the slave
nodes return the queried information to the master node under normal conditions. Under
abnormal conditions, the slave nodes return the specific error codes corresponding to the error
types.
Table 1-4 lists the error codes.
Table 1-4 Error code list
No.
Name
Description
0x01
Invalid function code
Slave nodes received
unsupported or incorrect
function codes.
0x02
Invalid parameter
Slave nodes received invalid
function code parameters.
0x03
Invalid data
Slave nodes received invalid
data such as CRC checking
error.
0x04
Slave node execution failed
Slave nodes failed to
respond to the command.
0x05
Reload the start command
Slave nodes are busy.