What is a accumulating timer for a car wash?
It is a timer which knows the value of time which it has and allows for additional time and money to be added. It removes the need to wait for the timer cycle to expire for the user to add more money.
An example is a self serve bay where you add $2 to start and 25 cents to extend the time using the bay for another 45 seconds. The process of adding the addition quarter adds an additional 45 seconds to the ongoing time which requires an accumulating timer. Or a timer which actually knows the value of time it has…. so it can add an additional 45 seconds.
A non-accumulating timer does not know the value of time it has…. which does not allow it to add any additional time to the cycle. This in turn does not allow the customer to add any money to existing time cycle until the time cycle expires.
In the bay example…. every time a customer would want to use your bay it would cost $2 and the customer would have to wait until the cycle was over until adding another $2 to start the cycle again.