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Correlate Multiple Alarms to Create Plain English Diagnostics

T/Mon SLIM Remote Alarm Monitoring System
T/Mon SLIM can correlate alarms from separate devices - and even tell you if events didn't occur as scheduled.

Derived alarms and controls are one of the most powerful features of T/Mon SLIM. Derived alarms are "virtual" alarms created through user-defined formulas that coordinate inputs from several alarm points and apply logical operators to them. One classic example of a derived alarm is the combination of a low battery AND a broken generator. Either condition isn't only a Major alarm by itself, but in combination they are a Critical alarm.

The value of derived alarms is that they provide a way for you to watch for alarm combination scenarios. You don't have to scan your monitoring screens to figure out what's happening with your network. If you've configured your derived alarms, you've told the T/Mon SLIM what to watch for, and it will keep track of your alarms for you.

And with a derived alarm formula keeping track of critical events, you don't have to worry that your staff will miss the significance of a cascade of alarms - the T/Mon SLIM will alert the staff to the true situation, and even give them detailed instructions on who to inform and what to do next.

Consider a scenario of what might happen with our example of the bad generator AND the bad battery if you did not have derived alarms. Tom, on the morning shift, receives the alarm that the generator isn't functional, acknowledges it, makes a note to schedule repairs, and goes to lunch. Marcia, on the afternoon shift, comes on duty and neglects to read the trouble log. She notes that the battery is low, sends a command to start the generator, and forgets to check whether the battery is recharged. That night, commercial power fails, there is no backup power, the site goes dark, and the network goes down.

Derived alarms are flexible enough to monitor and control nearly any aspect of your network. Our clients have devised many ingenious derived alarm applications that can give you better visibility of your network. Here are just four of the ways you can use derived alarms to get better visibility of your networks. If you're not using them, you should try them. NetGuardian T/MonXM

  1. Notification when scheduled events do not happen when they should. For example, notification can be sent if scheduled generator self-tests don't happen on time, or if tower lights do not turn on at the scheduled time.
  2. Operate a secondary notification device. You can use derived alarms and controls to create backup notification on other alarm devices. For example, one client has NetGuardians at several sites sending alarms to a T/Mon SLIM. The client has created a derived alarm based on an specified list of critical alarms from the NetGuardian sites. If any of the alarms on the list occur, the derived alarm triggers a derived control, which operates a control relay that operates a secondary notification device.
  3. Notification of LAN failure using a heartbeat alarm. In this application, two derived alarms and two derived controls are set to be an indictor of continued LAN function. The alarms are configured so the following sequence of events happens in a regular time period: Control Relay A triggers Derived Alarm B which operates Control Relay B which triggers Derived Alarm A which operates Control Relay A, starting the sequence over again. Data transport between the T/Mon SLIM and the relays is over LAN. Each alarm has a notification qualification time greater than the time period specified for the alarm-control sequence.

    If the alarm-control sequence operates normally, you'll never see an alarm. If, however, the LAN fails, one alarm will not be able to operate its control relay to trigger the next alarm in the sequence, and the alarm will be left standing. If either Derived Alarm A or Derived Alarm B appears in the COS or Standing Alarm screens, you will know a LAN failure has occurred.
  4. Notification of events that are only alarms when they happen at a certain time. Derived alarm formulas can include date and time terms. This allows you to set alarms for conditions that are not problems when they happen during regular business hours, but are trouble when they happen after-hours and weekends. For example, a door might be left unlocked 8-6, Monday through Friday. But the door should never be open at any other time. You can create a derived alarm that ignores the door during the workday but sends an alarm notification if the door is opened at other times. You can use similar derived alarms to keep you notified of after-hours uses of power, lights, air condition, and so on.

Read this free White Paper and find out if T/Mon SLIM is right for you

Get more information about T/Mon SLIM, the regional alarm monitoring solution you control. This free White Paper, "How to Build a NOC Without Destroying Your Budget" will help you determine if T/Mon SLIM Is the right solution for your network. Download this White Paper now to get more information about T/Mon SLIM.

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