Chapter 3: Using the Web Interface
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Assertion Timeout Example for Temperature Sensors
Assumption:
Upper Warning threshold is enabled.
Upper Warning = 25 (degrees Celsius)
Assertion Timeout = 5 samples (that is, 5 seconds)
When a temperature sensor's reading exceeds 25 degrees Celsius, moving from the "normal" range to the "above upper
warning" range, the PDU does NOT immediately announce this warning state. Instead it waits for 5 seconds, and then
does either of the following:
•
If the temperature remains above 25 degrees Celsius in the "above upper warning" range for 5 seconds, the PDU
performs the "assertion" action to announce the "above upper warning" state.
•
If the temperature drops below 25 degrees Celsius within 5 seconds, the PDU does NOT perform the "assertion"
action.
"To De-assert" and Deassertion Hysteresis
After the PDU asserts a worse state for a sensor, it may de-assert that state later on if the readings improve.
To de-assert a state:
To de-assert a state is to announce the end of the previously asserted worse state.
Below are good state changes that cause the PDU to de-assert the previous state.
above upper critical
above upper warning
normal
below lower warning
below lower critical
1. above upper critical --> above upper warning
2. above upper warning --> normal
3. below lower warning --> normal
4. below lower critical --> below lower warning
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