Fortunately, I don't need any of that stuff, most people don't.
What
you need isn't important. Unless you are 100% self sufficient (food, shelter, care, etc.) you rely on monies and services from others. So, what
they want is the issue as it drives what value you can offer them in exchange for those monies/services.
As to your claim of "most people", the statistics belie that.
https://www.rubyhome.com/blog/smart-home-stats/ indicates:
- 7 in 10 homebuyers are actively looking for a smart home.
- 78% of homebuyers would be willing to pay more for a smart home.
So, unless you plan on dying where you are, you will be influenced by these issues. Increasingly so, especially with the advent of AI "at the edge".
My vaguely-smart 'stat talks to the gravity furnace with, get this TWO WIRES! And it WORKS!.
As did the oil-fired, hot water heat furnace in the 70 year-old home I was raised in. No filters (save the one in the oil line) to replace.
But, cooling was achieved with open windows, fans and,
eventually, window-mounted air conditioners. Adjusting the temperatures of each of the areas served by those required making a circuit of the house to tweek each's settings, individually. But, "it works"!
Here, everyone has a furnace (of course). Some larger homes have two systems. Many have evaporative coolers. Most have central air conditioning. (We can ignore the needs of spas and swimming pools, for now).
HVAC control is not a trivial issue as how the environment needs to be "conditioned" depends on the outdoor weather; you'd not run the cooler in "Monsoon" and running the ACbrrr in "Summer" is just wasteful. Switching from one to the other inappropriately is wasteful of energy as well as leading to discomfort. If it's going to be humid tomorrow, then run the ACbrrr as it will be more effective and more responsive than the cooler. If it will be dry/arid, run the cooler.
If windows and doors have been open, then the filters in the AHU will likely need to be replaced more often. Of course, a function of how much air has passed through them.
You can make all of these decisions "manually", EVERY DAY. Or, have something else make them more intelligently leading to more comfort and energy efficiency.
My computers are all plugged in to a 1gT wired network and the fast stuff is on 10g fiber. Only thing on the wifi are the couple of tablets and my phone when it's at home or the office. When I do camera setups, it's almost all PoE and fiber if needed.
I have ~80 drops in my 2-bedroom office. The radio is turned off on the router (there are 4 other APs that serve the
private network, here). There are 30 cameras in place. Close to 300 PoE drops powered by a 5KVA UPS backed with a 5KWHr battery pack.
And when you talk of "new plants", most people aren't that; they might be a multi-zone heat-pump setup or along those lines
Here, HVAC systems tend to become inefficient to repair at the ~20 year mark. Service calls quickly dominate the TCO with older kit.
I don't know any of my neighbors who have plants older than ~15 years. Can you even
buy R22 anymore? How long do you want to keep nursing a SEER 10 unit along -- especially as electricity costs rise?
And BTW, it's a long stretch to describe modbus-rtu as a layer 7 protocol, I'd call it more like layer 2 but it really doesn't fit the ISO stack.
Layer 2 is a traditional serial port. EIA232 defines layer 1 and the "UARTs" (or SDLCs, etc.) on each end of that cable define Layer 2. A "frame" becomes a single character that the link conveys much like an ethernet frame is a set of octets.
The contents of the frames are meaningless at layer 2. They just get shuffled from point A to point B and nowhere beyond.
Modbus adds the concepts of addressing, data types, function codes, error checking, exceptions, etc. The data that is exchanged has
meaning.
"
Modbus (or
MODBUS) is a client/server data communications protocol
in the aplication layer." (from
Wikipedia)
By contrast, I can take a UART or a NIC and just move frames between A and B (e.g., AHU and condensing unit) without adhering to any constraints imposed by any of these other higher level protocols. What I choose to pass back and forth need not make sense to anyone or anything other than the devices on the terminals.