You need to get the EuControl Software directly from Avid. The .dll should just be the link between the EuControl Software and Nuendo.
You will need an Avid Account to download:
https://euphonix.avid.com/downloads.php
We are using a couple of Artist Mix and Transports this way and an S3.
Gonna try the Control App when I have time. Looks promising.
Is it possible to control Cue sends also??
Good question, I don’t use that functionality. The account and app are free so give it a try! john
Thanks to the OP for posting. I’m going to give it a try. Already have Eucon for other controllers.
Yes, it is.
And I find myself in the humiliating position of being the one dumbass in this crowd who can’t seem to make it work. Can’t seem to make the EUCON connection-- just getting its icon dimmed out on the iPad with a “no connection” triangle.
Anybody feel like walking through the Mac/iPad Pro process? I have a feeling I MAY have downloaded the wrong eucon software…
Thanks,
Chewy
Download the 19.12 Eucon unified install for Mac, connect your iPad to your local network and add an Eucon device on Nuendo. Other than that, can’t spot another potential issue.
Something must have gone wacky with my installation. Gonna try again.
Thanks, Miguel.
Chewy
It’s very important to have the same generation of Eucon software and Control App.
Yes, must be on the same software generation. Also, open the Eucontrol software (command + 1 on Mac) and ensure that under the Surfaces tab you have added your Avid Control (move from “All Surfaces” to “My Surfaces” if it didn’t do it automatically). john
Will Avid Control MIRROR ALL COMMANDS from Nuendo’s mixer and project windows? If I hide a channel in Nuendo, will that channel become hidden on the Avid Control screen?
Hey John, you have Nuage!! What are you using the Avid Control for? 
I use it in my home setup (Nuage is at the main studio) as well as to control my rig from the booth.
I just tried hiding a track in the Nuendo 8 mixer and it did not hide in Avid Control, I can try later on N10. john
Well, THAT’S really disappointing. They claimed to have fixed this on the Avid site. Then someone using Cubase said they didn’t fix anything. They’ve set it up to work with S1, so if you try using it with Artist Control, you actually lose features that HAD worked with the PT App. I’m talking really basic stuff like BANKING! 
Avid says they’ll fix this by 1st quarter 2020. We’ll see.
Anyway, now you’re saying that it’s great. I’m really glad they fixed the crashing issue. But even that is suspect since you were on an all Mac system. All of the PC people have never been able to get that tracks page to work without crashing! 
So I don’t really know what to think.
I’ve downloaded 19.12 onto my iPad. But I’ve been waiting to update my Artist Series hardware to 19.12 because it’s SO STABLE ON 18.3. I’m not sure how much use I’ll actually get out of it without the S1 hardware. What I do know, is that, without that Mixing Mirroring issue being resolved, I’m way more inclined to wait before firing mine up. 
The channel is hidden when its desabled.
I have an iPad for my home setup. Cubase IC and PT Control are installed on it. But as I work on post stuff, and have an intensive use of automation. So I use the iPad as an third monitor to show the automation panel. I only use Cubase IC or PT Control when on location with the laptop.
I know that the channel will disappear when it is disabled. I have offered that discovery as a work around on the Avid forum. This suggestion was immediately shot down because you lose the audio output when it’s disabled, as opposed to just hidden. That’s a fair point. But I was trying to point out the one desired advantage. Bottom line, that’s still a big problem. In fact, besides the tracks page crashing issue, I couldn’t think of a more urgent concern.
The thing about improving something is that it assumes you’re adding to something that works, not substituting it for something you had. They fixed the crashing problem. Great! But now I lose banking?
If they weren’t going to make Avid Control backward compatible, they should have left the PT Control App as an option for all of us Artist Series Users.
I don’t seem to be able to create an Avid account as I don’t have any Artist hardware. Boo-hoo 
Guess I’ll have to stay with Steinberg’s less-than-impressive iCPro.
I cannot believe they actually charged money for that!
their serial number validation isn’t particularly robust … just sayin’
@fenderchris: You can create an avid account with no hardware on the main avid site. Afterwards just install the app on any device and it will activate the eucon suite for download based on your login data. I don’t own any avid hardware also. Just did that and tested it on my lg g2, how nice they have android support now.