SDC-650 Multiple door controller
5
Step 3: Connecting the RS-485 reader network
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– Saflec Systems (Pty) Ltd.
http://www.saflecsystems.co.za
Step 3: Connect the RS-485 controller network
All controllers in a specific network will be connected together via an isolated multi-drop RS-485
network. This network will be connected as detailed in the figure below.
Figure 5
Wiring configuration for multiple controllers on the RS-485 controller network
NOTE:
The RS-485 network requires termination on the first and last controller on the line by
shorting J6. Controllers in the middle of the line must not have the termination jumper inserted as
this can cause network problems.
In the diagram above you will see that the controller on the left is terminated while the controller
on the right isn’t. This is because the cables go off to another controller; hence the controller is in
the middle of the line and must not be terminated.
Step 4: Connecting the RS-485 device network
All readers or IO expansion boards are connected to each other via an RS-485 multi-drop network
which is connected to the controller as detailed in the figure below.
Figure 6
Wiring configuration for an SSR reader on the RS-485 device network
