How to calculate availabity using tag values

[srinivasan_s]

I want to calculate availability.
Actual formula i am using is,actual hour/planned runtime. here planned runtime is memory tag.
for actual hour, i am using
machine_up_status- machine_down_status.
I want to find time between machine_up_status and machine_down_status.
here are questions:
how to find that time between two tag.

[Transistor]

Your question is very unclear. Please edit (click the pencil icon) to fix.

• Use a capital letter at the start of each sentence. It helps to make it clear where the sentence starts.
• You mention machine_up_status and machine_down_status but you do not have tags with those names.
• You mention actual hour but don't explain what this is and there is no tag.
• What is machine_up_status - machine_down_status supposed to tell you? Are these supposed to be the time the machine was running / not running in the past hour? Note that if the machine ran for 30 minutes and stopped for 30 minutes that this expression will give a result of zero.
• Mark code, expressions or variables by enclosing them in backticks. e.g. `variable name` will render as variable name.