I would pay for an addon card for my P4 to have wired ethernet.
Here is my Hydros collective I am logged into using the emergency mode with my router unplugged so there is no wifi or network communications. I took several screenshots of logging in in the emergency mode where it uses bluetooth for logging in.
This is the app trying to connect normally.
Once it gives up the screen below is displayed.
You click on enter emergency mode and you will get the next screen for a few minutes.
Then it will give you a choice of which collective or controller you want to select.
For this I clicked on my collective aquarium control. and then this screen comes up for a while.
Then this will pop up for you to enter the emergency mode password you setup when you turned on allow emergency mode in options in the left menu.
Once I put in the password this comes up. If you are not familiar with Hydros normally you have inputs and outputs setup on individual pages instead of all on one like it is in emergency mode. The first things listed are the member controllers. The top one on the left with the three overlapping circles is the collective wifi master. It is the one that currently communicates with the wifi devices such as the wifi power strips. As you can see all the wifi icons are red indicating the controllers cannot access wifi. The second screenshot below are more of the controllers.
Below is the start of the inputs. It defaults to text mode with the inputs and outputs but I already selected tile mode since I like that mode better. You will have to do that each time you use emergency mode in the normal app operations that is saved and will come up how it was last saved. None of the inputs are red so that is good on this screenshot.
Below is another screenshot of more inputs. The ones that show as unconfigured or None Never have to have internet to show. The unconfigured ones are test that taken at a specific time and the time is usually also displayed. The None Never ones are static inputs which are ones manually entered.
Below is the remainder of the input in my collective and the start of the outputs. The outputs that are highlighted in blue are on. The grey ones are off. The ones with the lightning bolt to the left are outputs that have power monitoring.
Below is more outputs. The ones that are completely orange are in override on or off mode. It could be due to a timed event such as a minimum on or off time set in the output. The colors on the EcoTech outputs just denote where the pump is located like same side, opposite side or back.
Below is more of the outputs.
Below are more outputs. I guess I have a lot of outputs setup.
Below is the end of the outputs and the wifi devices and third party devices. The all red tiles is because those are access via wifi or internet and at the time these screenshots were taken there was no internet or wifi.
So you can access the controller or collective if you are onsite using bluetooth. You can even override the outputs if you need to or click on a mode and it will go into that mode. Of coarse there is not way to change any outputs on the wifi devices with no wifi so those cannot be set to a override mode. If it was just no internet then those would still be controllable. The screens below were taken with no internet but with wifi working. These two show the only basic differences from the ones already posted. The first one you can see the wifi icon on the controllers is orange instead of red. That indicates there is wifi but there is other communication issues which in this case is no internet since I had my cable modem unplugged to get the screenshots. The second screen just show the wifi and third party devices which are not red since the collective can still communicate with them.
Hope this is a help in how to access you Hydros without wifi or internet in emergency mode.