User manual

Wide Bank 28 DS3 - Release 2.4 July 2004 7-3
Diagnostics & Troubleshooting
LED Test and Status Indicators
Power LED
There is one Power LED for each of the two Controller cards. Each indicates the status of the power
supply on its respective Controller card.
Alarm Cutoff (ACO) LED and Pushbutton
There is one alarm cutoff LED and pushbutton switch for each Controller card. Each alarm severity
(critical, major, and minor) has its own ACO function, though major and minor alarms share the
same relay contacts. When an alarm condition occurs, the active Controller energizes the alarm
relays for that alarm severity, providing open or closed contacts on the alarm output connector on
the rear connector panel, depending on the alarmout command setting. The connectors can be wired
to the facility alarm system to provide audible and visual alarm indications for each alarm severity.
See Alarm Contacts on page A-3.
You can silence or suppress the current alarm outputs by pressing the ACO pushbutton on the active
Controller (the Controller with lit alarm LEDs). This deactivates the currently active alarm relay
contacts and lights the ACO LED. However, if a new alarm condition occurs, the ACO function for
that alarm severity will be reset and that alarm output will resume. ACO operation is also reset when
the alarm condition is cleared.
State Meaning
OFF –48V failed
GREEN Power Supply is functional
RED On-board power supply (5V) failed
Color Description
OFF Alarms active
YELLOW Alarms suppressed