Runnig PlexConnect on a different machine to server

I am currently running my media server on an old pc, but I am having trouble installing PlexConnect and getting it to work on my ATV3. I understand that I am able to install it on a different machine to my server (MacBook Pro in this case), but would I need to have my MacBook running every time I want to use it on my ATV?

Yes, also you can use another host for PlexConnect like a non aTV jailbroken iOS device or a rPI for example.