Alpha Technologies Serial System Controller User Manual

Page 14

018-332-C0-002 Rev. B

1. System Overview

Figure 1-3; LED Block, Reset Switch

1.2 Indicators & Connections, continued

1.2.3 LED Indicators

The SSC Alarm LED reflects system level alarms. When a system level alarm is active,

all LEDs will periodically (every ten seconds) turn off, and an alarm code will be

displayed. (See section entitled Alarm LEDs for more information.)

The Ready LED flashes at a rate of 1 Hz to indicate that the SSC software is running

normally. Generally, this LED is only turned off while alarm codes are being displayed.

The External Bus Comms LED (on left) indicates active communication on the

external RS-485 or RS-232 interface. Generally, this interface is where a Digital

Transponder connects to the SSC.

The System Bus Comms LED (on right) indicates active internal communications.

The Left System LED is not used at the time of this publication.

The Right System LED flashes to remind the user of a pending tamper alarm. After 30

seconds, the alarm will activate if not disabled. Once the tamper alarm is activated,

it will remain on until either: the Reset switch is pressed 3 times consecutively; the

door is closed again; or the alarm is disabled through status monitoring.

The Right System LED also indicates the number of devices (XM2s and SSCs) actively

communicating with the SSC on the Alpha Bus.

1.2.4 Reset Switch

Performs two functions:

Latches the system configuration

Disables the tamper alarm

When all devices are properly communicating on the Alpha Bus, latch the system

configuration by pressing and holding the Reset switch for 3 seconds or longer.

(Latching tells the SSC: Remember the configuration of the system as it is right

now.) At the end of the 3-second period, all LEDs will flash quickly to indicate

successful latching of the system. If this step is not taken by the user, the SSC will

automatically do it 30 minutes after power-up.

Note: The SSC does not remember system configuration when it loses power.

If any device on the Alpha Bus stops communicating with the SSC, or

any device is added to the bus after the system configuration is

verified, the SSC will generate a Communications Failure alarm.