DSX Access Systems, Inc.

Controller Communications

Controller Communications Overview

The first panel of every Location is designated as the “Master”. All subsequent panels, at the same Location, are designated as “Slaves”. Any DSX panel may be selected by dipswitch settings to work as a Master panel. The Master panel performs all of the same functions as a Slave, but is also responsible for polling all Slave panels and reporting the history transactions to the Host PC. The Master panel does not make access control decisions for the Slave panels. It is simply the messenger for information from the panels to the PC and for information from the PC to the panels.

The Location Masters may communicate with the Host PC via a combination of direct serial port connection and dial-up phone modems. The Master of a modem-controlled location automatically buffers all normal transactions until its buffer reaches 80% of capacity. When the transaction buffer reaches 80%, the Master panel automatically initiates a phone call to the central monitoring PC and uploads all transactions. If an alarm event occurs, the Master panel initiates an immediate call to the PC to report the alarm. The PC may be programmed to routinely poll each of the remote modem Locations and collect the logs automatically.

The panels communicate using a RS-485 communication network. The panels are connected with a two twisted pair cable that is run in a series loop or daisy chain fashion. Star wiring or home run wiring configurations can be achieved with a DSX-1035 communications Quadraplexor. The Quadraplexor provides multiple outputs for panel to panel communication.