Temperature offset

[Deadeye]

I've got a probe at the heater outlet and one in the mash. I control with the mash probe. However, I notice when the grain bed is becoming compacted and the flow is droping off, the temperature of the heater outlet climbs rather significantly. Is there a feature that will maintain temperature using the mash probe but limit the heater output based on the difference between the two probes? For example, if you are controling the mash at 150 F and dont want to heater output to be above 155 F. Perhaps an alarm on the heater outlet probe based on the delta between the two probes that would let you know the grain bed needs to be stired.

[brewdude]

I haven't tried this but you could set an exit condition of the state "mash maintain 150" to "heater output > 155" then go to a "rest" state that turns off the heat, then that state has an exit condition "heater output < 155" to go back to the "mash maintain 150" state. You can continue the timers between the states, so you can still mash for 60 minutes.

"Mash Maintain 150" state, PID to mash temp, exit if timer > 60 min or heater output > 155
"rest" state, heater off, exit if heater output < 155 go to state "Mash Maintain 150"

Rick.

[Deadeye]

Interesting. I'll have to try that out.
Perhaps a second timer on the rest period to wait a minute or two before rechecking the heater out temp.
Does the 60 minute timer have to be in a separate process?
Figuring out how things work from a wiki isn't all that educational.