I have 4 relays I want to monitor when they go high and how long the stay high. The program with turn them on and off and a set time. So being able to control the relay on line is really not needed. What would be the best way to implement this task.
That is a very broad question. But I would implement a timer that would start counting when the relay turns on and stops when the relay goes off. Then, save time difference in a variable that you would save on a file or display on a web server – it depends on the aim of your project.
Alternatively, if you’re getting track of the time (day, hour, minute), you can save the time when the relay goes on on a variable, and save the time the relay goes off on another variable. This way you’ll have the time that it started and the time that it finished.
I’m not sure if this was the kind of advice you were looking for. Let me know if you were looking for something else.