Fuel consumption "live"

Hi
I will like to make a live fuel calculations.
The informations I have, is a "live" fuel rate in "Liter/hour"
This number i get from a monitor software for a engine.

I will like to hava a "Total fuel consuption" number.
How can i get my live "Fuel rate" to a live "Total fuel consumption" ?

I also want it to be possible to freeze the "Total fuel consumption" in another row.

Can sombody help me ?


Setup

[Engine 1] [Fuel rate] [Total fuel consumption] [Freeze total fuel consumption] [Difference total fuel consumption]

Fuel rate in litrer/hour
Total comsumption in liters
Freeze Total comsumption in liters
Difference Total comsumption in liters

can anyone help me ?

I guess you would need to establish a time interval for that. so put a start time and end time somewhere, deduct the 2 to establish elapsed time * fuel rate in ltrs/hr = total fuel consumption for that period.Good luck