
Communications
38
AC-425x-B Hardware Installation and User Manual
The distance between the computer and the access control panel must be no more than 150
feet (50 meters).
If the baud rate is increased to 57600 or beyond, the distance must be no more than 30 feet
(10 meters).
Table 5: RS-232 Connection
Access Control Panel
DB9 Connector
DB25 Connector
GND
Pin 5
Pin 7
Tx
Pin 2
Pin 3
Rx
Pin 3
Pin 2
6.1.2
RS-485 Connection to the Computer
Set the J1 switch to the RS-485 position.
Using the RS-485, up to 32 access control panels can be linked together and connected to a
single communication port on the computer (Figure 18).
Figure 18: RS-485 Panel Connection to PC
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-425x-B supports the 2-wire RS-485 interface, which can significantly increase the
distance between the server and the last panel. To use the RS-485 interface, the panels must
be connected in a daisy-chain formation with an MD-14U RS-485 to RS-232 adapter
(Section 6.1.3).