User's Manual

33
Installing 5000/5100:
Wiring
2.2.3 RS-485
Connections between every two terminals are set up through RS-485 interface. When
more than two of the terminals are connected (as a multi-station system), a host only
needs to connect to the first one terminal (master) and it can then communicate with
the rest terminals (slave).
On the last slave device, a termination resistor is usually essential. There is one
terminator on the PCB of each terminal, and a DIP switch (s1) is beside JP3. When
the terminal serves as the last one slave device, please turn on the switch.
Figure 20: Terminator’s switch
Slide the DIP switch to the right position on the last salve device.
To establish such RS-485 connection, the following settings need to be done first on
the hardware of the terminals. For preloaded applications, set parameters from the
front panel by entering the Setup Menu.
>> Also see Section 3. System Architecture
z
Line Connection:
Only the device connected to a host is named “Master”, the rest are all “Slave”.
z
Station ID:
Assign a unique ID (01 ~ 99) to each terminal.
z
Maximum station ID:
Set a value (01 ~ 99) as the maximum station ID of the polling list on the Master.
For RS-485 connection without any repeaters, up to 32 stations can be connected.