Communications
36
AC-425 Hardware Installation and User Manual
6.1.2
RS-485 Connection to the Computer
Set the J1 switch to the RS-485 position.
Up to 32 access control panels (AC-425, AC-225, AC-215, or AC-525) can be
linked together and connected to a single communication port on the
computer.
Use the RS-485 interface for situations where there are multiple controllers
connected. The serial port used to control the access control panel is assigned
within the AxTraxNG software.
The AC-425 panel supports a 2-wire RS-485 interface. Using the RS-485
interface can increase the distance between server and panels up to 4,000
feet.
To use the RS-485 interface, the panels must be connected in a daisy-chain
formation with an MD-14 adapter.
The recommended cable type to be used is STP cat5 (shielded twisted pair
category 5). We recommend using a 20-24-AWG cable.
6.1.3
Daisy Chaining
You can connect up to 32 panels to a single serial line using a daisy-chain
formation.
The first panel is connected directly to the server using an MD-14 adaptor,
while the second panel connects to the first panel. Additional panels are
connected in the same way, one after another. The maximum distance from
the PC to the last panel in the chain is 4,000 ft (1,219.2 m).
Figure 20: Daisy Chaining
