18
Figure 3 wiring method is not recommended
Figure 4 is incorrect wiring method
When multiple ARTU network use, the last of the RS485 should A and B on the terminal and A terminal
matching resistance R, impedance matching, to ensure the communication terminal matching resistance generally
between 120 Ω Ω - 10 k, wiring terminal matching different resistance may be different.The above diagram shows the
use of a three-core shield wire, with the shield layer connected to the ground and G1 terminals of each device
connected.
5.6
Debugging and maintenance
5.6.1
Use instruction
1) Check whether the power cord is properly connected before power on.
2) After the POWER is switched on, the POWER indicator will be on and the RUN will start flashing at the same
time. The interval is 1 second.
3) Establishment of communication
a) Correctly access RS485 bus and connect to the upper computer.
b) The upper computer issues commands according to the station number and baud rate of the module and in the
format of the protocol.At this point, the module's communication indicator flashes, indicating that the module has
received the command from the upper computer and responded, that is, the communication has been established.
5.6.2
Debugging
1) Check whether the power supply is connected correctly before power on.
2) After power on, observe whether the power lamp is on. If it is not on, it indicates that the power has not been
added.
3) Observe whether the running light flashes. If not, it indicates that the module does not operate normally.
4) Communication is established only when the communication indicator flashes.
Set the upper computer query time interval.Since the bus is half duplex, the upper computer should set an appropriate
time interval, which should be determined according to the length and baud rate of module response command.
Improper setting of time interval will lead to communication failure
