There are fundamentally three parts or phases to implementing a custom control system.
The first is to determine what you need the system to do. All of you know what you want to do at the basic level. You want to turn lights on and off at the correct times each day. You may also want to turn fans on and off with the lights or you might opt for using temperature to control the fans.
The next step is to determine what hardware you must have to implement your design.
The final step is to program your system to make the hardware control your lights, fans, etc.
We intend to cover all of these topics over a few weeks time.
My little veg tent has a small space heater in it to insure that we don’t get too cold. Initially I used the temperature setting on the space heater but that proved to be a disaster! The accuracy of the thermostat on the heater is so poor that the temperature spent more time in the high 80’s than the desired high 70’s and while the heater was running, the A/C was running. Arrghhhhh…
The answer was to add proper temperature (and humidity) sensing and let the PLC determine which equipment is on or off based upon a single temperature input rather than letting each device do what ever it wants to do independently.
Now, when the lights are on and the temperature reaches 82 F, turn on exhaust. If it then reaches 83 F, turn off exhaust and turn on AC. When temp reaches 75 F (going down) turn off AC or Exhaust. If temp reaches 72 F going down, turn on the heater until the temperature reaches 78 F.
Problem solved! Temperature locked in and there is provision for if it gets out of control.
I have not done this (yet? LOL) but it is certainly possible to have the system send email notifications if certain conditions occur. An example might be high temperature warning.
Normally, you would design your system to do the bare minimum to start. Then as you watch the system and how it performs, you might see an opportunity to improve things. You might, alternatively, decide that the basic operation is all you need or want. It is entirely up to you.
Your imagination and the needs of your plants are the only limitations on what you can do with one of these systems.
I should have posted a couple of photos earlier, here are photos of my control system and user interface panel:
Wiring is a bit of a mess as I am in the process of an upgrade
This is the main screen for an overview of the system
This screen allows for UV light setpoint changes