Fabric Watch Administrator's Guide v7.0.0 (53-1002153-01, April 2011)

Fabric Watch Administrator’s Guide 19
53-1002153-01
Fabric Watch alarm behavior
2
Above event trigger
Set the Above event trigger for an element that requires only high threshold monitoring. In the
Above event trigger, Fabric Watch triggers an event immediately after the data value becomes
greater than the high threshold.
Define a buffer zone within the operational limit of an area to suppress multiple events when the
counter value goes above the high threshold and fluctuates around it. The next event will not occur
until the counter value falls below the buffer zone created by the high threshold. Figure 4 shows an
Above event trigger with a buffer zone. The Above event trigger occurs when the counter crosses
the high threshold (event 1 in Figure 4). When the data value becomes less than the high threshold
and buffer value, Fabric Watch triggers a second event (Event 2) to indicate that it has returned to
normal operation. The second event will not be triggered until the counter value falls below the high
threshold and buffer values.
FIGURE 4 Above event trigger with buffer zone
Below event trigger
The Below event trigger generates an event when a data value becomes less than the low
threshold boundary.
When a buffer is defined, the event will be triggered only when the value goes below the lower
threshold. A second event will not be generated until the value crosses the buffer region set above
the lower threshold.
Fabric Watch alarm behavior
Fabric Watch alarm behavior depends on the threshold states associated with the Above, Below
and Changed thresholds. Threshold states can be INFORMATIVE, IN_RANGE, and OUT_OF_RANGE.
Notifications are generated only for the following transitions:
• IN_RANGE to OUT_OF_RANGE
• OUT_OF_RANGE to IN_RANGE
No alarm is generated for INFORMATIVE to IN_RANGE (or IN_RANGE to INFORMATIVE).