Very interesting paper on survivability of Modbus monitoring network after nuclear war (PDF)
These guys have duplicated most of my strategy which I developed independently before I had read their paper on the subject.
The reason the scope has changed for me is the rapidly dropping price of Modbus peripherals. What formerly cost $500 and $100 is now $10 on EBay and in the future it is inevitable they will drop even lower.
Once you are operating in an economic arena where Modbus is just as cheap as I2C it becomes obvious Modbus is vastly superior to 1-wire because it has been heavily debugged in industrial settings and intensive use. I experimented with 1-wire for years and it is not even remotely as safe or easy to run over long lines as RS-485 Modbus.
I am including my former I2C code for CD-OS on Github but my focus now is entirely on getting a Lua-scripted process driver for Modbus monitoring going. That is going to be the baseline and users can create whatever other services for protocols they want to add to it, whether CANBUS or BACNET, etc.
Once you are running on Modbus, providing cheap optical isolation at different points is not hard at all. You can add it to the RS-485 lines with ease and anything else connected at a much lower price threshold. It is also simple to connect cheaply from Modbus to TCP-IP with a small box that has dropped from $300 in 2005 to $30 nowadays. Once you have Modbus connected to TCP-IP then you can monitor any device in the shelter or retreat by just tapping off the network and gettings the signals into the Lua-scripted service I mentioned above. If you have to connect devices outside the shelter (weather sensors, security cameras, generators, door keypads) you go to true optical over a TCP-IP converter which itself is around $40 nowadays. Things I built from scratch in 2005-2008 now come as plug'n'play devices with configuration built-in. This makes Modbus the default protocol for CD-OS, at least for the first release.
I absolutely guarantee I will have CD-OS version one in Github this year. I was thinking of putting it up last night as-is but I am still tweaking the inventory/barcode recognition stuff and similar functionality. I made this list of mandatory stuff that has to be in version one before it goes up and am still working on these features. I have very high standards for things that I release as my own work.