I had to separate the mash & boil processes since there's an 8 state limit. A couple of things concern me. In process0/state0, if the MLT pump fails or becomes clogged (stuck mash), the HEX element will boil the reservoir water. I guess I could set the HEX element under PID control at a temperature just under boiling, instead of direct 100% on.
I'd like to automate more if possible. Maybe using water level switches and valve actuators. Any suggestions would be great.
Great diagrams. One thing that isn't clear is which temperature probe do you want to associate with the heating element PID? Or in other words, which point in your system do you want to maintain control of the temperature?
Most people would say that the output of the heat exchanger is the best spot for the temperature probe that controls the element, in your case the output of the plate chiller. If you control it with the hex temp itself, you may slow your system response time, unless there is 100% efficient heat exchange. The temp of my heat exchanger is routinely 20deg+ of my wort setpoint, mainly because my heat exchanger is extremely inefficient. But the PID makes up for the system inefficiencies.
But regardless of output association, I agree that Proc0/State0 shouldn't be Direct On. Set it to be PID controlled to whatever temp you are shooting for, 165. Don't worry, it'll be on 100% until it gets close to the setpoint.
