Learning How to Create Behavior Models - How to Use Alarms - How to Create an Alarm -
What is an Alarm?      Enabling an Alarm

How to Create an Alarm

As in the last scenario, you want to know which of the CriticalDevices nodes are experiencing high traffic. Now that you have created the poll 1CheckTraffic, you must create an alarm that will notify you when NerveCenter has detected high traffic.

This scenario includes five activities:

1. Creating a New Alarm
2. Designing a State Diagram
3. Enabling an Alarm
4. Modifying an Alarm's State Diagram
5. Adding Another State to an Alarm

Creating a New Alarm

This first activity will step you through the first stage of creating a new alarm that monitors high traffic.

 
  To create a new alarm:

1. Open the NerveCenter Client and connect to the appropriate NerveCenter Server.
2. From the Admin menu, choose Alarm Definition List.

   

   NerveCenter displays the Alarm Definition List window.

   

   This window lists all the alarms in the NerveCenter database.

3. In the Alarm Definition List window, select New.

   NerveCenter displays the Alarm Definition window.

   The Alarm Definition window allows you to examine, create, or change an alarm definition. The definition is implemented through the state diagram. The next activity will step you through the process of designing the state diagram. First, you must name the alarm and limit the nodes it will monitor.

   

4. In the Name field, type 1HighTraffic.
5. From the Property list, select the myNodes property.

   By selecting the myNodes property, you are limiting the alarm to monitor only nodes in the CriticalDevices property group.

   In this case, limiting the nodes is redundant, because you have already limited the related 1CheckTraffic poll to this property group. If you had wanted the alarm to monitor all the nodes in your network, you would have selected the property NO_PROP.

6. From the Scope list, select SubObject.

   By selecting the SubObject scope, you are telling the alarm to monitor each port on each CriticalDevices node separately.

   Using scope in alarms is an advanced topic that is discussed in How to Use Alarm Scope in Behavior Models on page 85

7. Select Save.

You have just set the parameters of your new alarm by naming it, limiting it to the CriticalDevices property group, and setting the scope to the SubObject level. In the next activity you will design the core of the alarm, the State Diagram.

Designing a State Diagram

This next activity steps you through the process of designing a state diagram for the 1HighTraffic alarm.

 
  To design a state diagram:

1. From the toolbar at the top of the Alarm Definition window, select Add State. NerveCenter displays the State Definition window.

   

2. In the Name field, type Busy.
3. Under Severity > Traffic, select Low.
4. Select OK.

   The State Definition window closes. An icon appears in the top left corner with the name of your new state, Busy, and a bright green color, indicating a low severity.

5. Position the Busy state icon in the middle of the state diagram.

6. From the toolbar at the top of the Alarm Definition window, select Add Transition.

   The Transition Definition window appears.

   

7. In the From list, select Ground. In the To list, select Busy.

   You are creating an instance when the alarm will transition from the Ground state to the Busy state.

8. In the Trigger list, select portTraffic.

   You are telling the alarm to transition to the Busy state whenever NerveCenter fires the portTraffic trigger. In Chapter 3, How to Use Polls you created a poll that would fire portTraffic under certain high-traffic conditions.

   The Trigger list in the Transition Definition window contains all the predefined triggers and user-defined triggers in NerveCenter's database.

9. In the Actions area, select New Action.

   A list of alarm actions appears. You can associate one or more of these actions with each transition in a state diagram. A transition does not need an action.

10. From the alarm action list, select Beep.

    The Beep Action window appears.

    

    Some actions require additional information. For the Beep action, the beep's frequency and duration can be changed. Notice the fields include default values.

11. In the Beep Action window, select OK.

    Beep now appears under the list of actions for this transition.

12. In the Transition Definition window, select OK.

    In the state diagram, a transition named portTraffic connects the states Ground and Busy.

    Notice the transition name, portTraffic, is the same as the trigger that causes this transition.

13. In the Alarm Definition window, select Save.
14. Select Cancel to close the window.

You have just completed creating your first alarm. In the next activity you will enable the alarm and the poll to test it out.