If you have a Display module, you can control the Apex without any network connection. But as a best practice, put your Apex and your router on a UPS battery for backup power. The Apex can even be integrated with the UPS so it knows when the power is out, so it can turn off high-power devices like heaters, lights, and pumps to preserve the battery life for water movement. See my tutorial on Apex Power Monitoring for details to set this up:
https://www.reef2reef.com/ams/neptune-apex-programming-tutorials-part-4-power-monitoring.698/
I know how to do it. I am not paying for a display that will go bad in a year, and costs way too much money. I think that there could be a better way to deal with power down situations. Blue tooth comes to mind. Or perhaps gasp! the old USB. Or even make the controller a hot spot. Many ways to deal with this situation. Adding more battery back up or worse yet having to branch multiple things off of my generator isn't something I want to do. A clean solution from APEX would be better. I am just noting that it isn't nice they way they implemented it.
I had to find all of this out the hard way when they came to update my power poles. You find out real fast where the holes in your system are.
I also have to say that in the last few years APEX has become less interested in customer feed back and like all companies eventually will, they are starting to succumb to themselves. When a company becomes completely focused inward they cease to be of any value or help to their customers.
The little *** for tat war with EcoTech also signaled to me that they are more interested in politics than they are with making what customers need and want.
I have had APEX for a long time and up until recently I have really liked them. They haven't done anything concretely that tells me that the gig is up, but the subtle hints are making me not trust them.
Also on the AFS why is it that they can't seem to get motor quieted down. The product, except for the programming, is solid but the motor noise is a joke. The DOS's drift, and I never bothered to try out the CORs because APEX.
GHL is no gawd send either. The people at GHL are hardware people and their software shows it. Fortunately for me I get the gates and the thinking, but it took me a bit to make the transition. APEX is way better in this regard. Though I think APEX could have done a lot more to make the programming more like programming. This coming from a software engineer.
Neither is perfect, but I am moving steadily to GHL because hardware failure is no joke and though I haven't had problems with APEX I fear their current popularity/marketing direction. I don't think it will end well and I don't want to be on the wrong side of it.