Vary the Duty Cycle of an output

[ECC]

--EDIT-- New Duty Cycle feature added, see below --EDIT--

This is an example of varying the Duty Cycle of an output.

For instance, say that you have a heating element that you want to use to bring water to a boil. Due to the wattage of the element, 100% is too much. But through experimentation, you've found that 75% on, 25% off maintains the proper boiling rate.

A simple 2 state process will give the desired results.


In State0, we setup a timer to count down 3.0 seconds. The element is ON during this time. The exit condition of State0 is when the timer has reached zero, at which time it transitions to State1. During State1, the element is OFF for 1 second. This gives and effective duty cycle of 75%. The cycle repeats until the process is disabled.

[ECC]

Although the method posted above still works, we've added a new feature to allow outputs to be controlled with variable duty cycles in any state, as well as Manual Mode. This should free up states to be used elsewhere, and make it simpler to achieve the desired functionality. Now there are 4 ways an output can be controlled in a state:

1. Directly Controlled (on/off)
2. Duty Cycle Controlled (%on over 10second period)
3. Differentially Controlled (Setpoint +- deg)
4. PID Controlled