@638 

Do you mean you want to connect EAP235 Wall with mesh? Unfortunately, wall APs don't support mesh, and there is a good reason for that.

Wall-plate APs are the most fixed APs in the network, so adding the mesh is not a cost-effective solution as most people will not use that. Normally, the mesh is for APs that may be moved from time to time, or outdoor environments where providing data cable would be hard.

EAP110 is not mesh compatible because mesh works on 5GHz and EAP110 is 2.4GHz only.

*But one thing I'm concerned about is that when your outdoor EAP is connected to the same switch, the controller should find the wall EAP through the cable connection. If you connect your laptop to that PoE switch, are you able to ping both devices? you said network discovery could find wall-plate AP, so from where it gets the IP address? also try t complete the outdoor AP configuration so you become confident that it is connected t the network, then do a test again. One other option is to connect your laptop to that switch and run Omada Discovery Utility. 

  @638  Its not very clear what you have going on due to possibly referencing more than one switch and not being clear on which EAP you are talking about at different times. After unscrambling my brain, this is what I could come up with. Is this what you have configured and if not you should probably use Visual Paradigm Online or some other tool to visually represent what you are doing.

As previous member stated, the EAP 110 and EAP 235 are not Omada Mesh Compatible. 

  @RamtinR 

Thank you for your suggestion of pinging the AP.

t seems the misunderstanding lies in my mixing up the term "Mesh" with the term "Omada". You are right, I do not want to move this wall plate around the building but I do want to have a single apparent wifi access point which covers the entire premises which I hope will simplify the nuisance of connecting to various APs all having different SSIDs.
The 2.4Ghz EAP110 can't do mesh but it can & does do Omada. The EAP235 Wall should do this too.

I will try another way to describe this system
Hard wire = ---          Wireless = ((()))
==================================
Internet---Router---POE Switch#1---EAP110
                                                      ---EAP225#1))))))wifi))))
--------------------40 metres --------------------
((((wifi(((((EAP225#2---[CONCRETE WALL]---POE switch#2---EAP235 Wall))))wifi)))
==================================

So I went to plug the EAP235Wall into the  POE switch#1. Omada found it & got an ip address. I adopted it into Omada. It worked. 
Then it went back onto POE switch#2. Omada sees it but declares it as disconnected & it isn't advertising the default SSID any more. 

I connected a laptop to POE switch #1 as you said. I can ping the router & I can ping the EAP225#2 but not the EAP235 Wall. The router client table says its IP address is disconnected.
I plugged the laptop into the EAP235 Wall ethernet socket & tried to ping it but received no reply.

I don't understand enough about this networking jazz to be able to solve this so please help.

Alec.

  @638 So it sounds like the EAP235, when connected to the POE Switch#2, is not part of the network for some reason.  The nearest I have come to what you are doing is a MESHED EAP225 connected to a POE switch and 3 cameras also connected to that same switch and that works without issue. For that reason I would expect your setup to work the same, since the cameras are able to obtain network information.

My first step, if you have not already, and even though it is powering up, would be to try a different ethernet cable on the EAP235.

Wish I could be of more help.

  @638 

I figured the same topology from your first post. So for some reason you cannot see the network from the switch port connected to the wall AP, connect the same cable to the laptop and see if you can ping the controller from the same cable that connected to the EAP235. Some PoE switches has port isolation, check if it's not activated. As other suggested, also change the cable. One thing you should make sure is that you can see the Router and Controller from the PoE Switch.

  @638 Thanks, Guys.

All sorted. Dicky cable.