We would like to monitor an attribute to have Spectrum alarm when the value changes. How can this be achieved
You can use the DELTA function in the Watch Editor GUI.
For instance if you wanted to create a watch when the value of Agent_Port changes, you would set the expression as:
DELTA(Agent_Port)
In the Threshold window select the Attach a Threshold
Set the Threshold Violated if value does not equal zero (!= 0)