This is my problem:
I have tag A created. I want to check whether value of tag A is smaller or equal to the value of tag A ‘n’ seconds/samples ago.
I have tag B. I want to check whether tag B’s value is between 200 and 1000 for more than 30 seconds.
I plan to create a boolean tag C as an expression tag whose value will become 1 if both the above conditions become true.
If the tag C value becomes 1, I want to issue an alarm.
However, I am having problem creating the first condition with tag A. How can I write an expression for tag C that will check if current value of tag A is smaller or equal to the the value of tag A 5 seconds/data samples ago?