So here's my reason for asking:
Tractor - ck20s with factor single rear remote, no more available.
Original plan - from rear remote feed to solenoid operated valve which just like 3rd function for loader allows for 2 sets of remotes. Simply cascading that concept would allow for an additional set of remotes.
New thought and hence this thread - Consider how a backhoe hydraulics attach - connect to rear remotes on tractor, set rear remote valve open (tractor valve has detent so it stays open.) and now the backhoe is "live". So building on that concept I started thinking well why not have a similar spool valve mounted on the rear of the tractor fed by the tractor's rear remotes just like the backhoe. In that case leaving the rear remote open will not dead head the system and will give as many remotes as come with the spool valve. (I'm thinking 3 is plenty for my needs.) For typical circumstances leaving it at that would be sufficient. Anything hooked up could then be controlled via the corresponding valve control on the spool.
The reason I ask for an indent to hold any/all the valves in the open position is if for example I hook the backhoe up to one of those valves. It requires the valve to be held open for it to operate.
so that's it in a nutshell. By using a spool valve it simplifies a lot of the "plumbing", there's no need for solenoids/electrical connections/switches which also simplifies things and makes a cleaner setup.
I suppose if no such spool valve exists (I'm guessing not) then as an alternative I could have a manual valve between the rear remotes and the spool valve that would have 2 output options - one feeds to the spool valve and the second feeds to a set of quick connects. So when hooking up something like the backhoe I'd manually throw the valve to feed to the quick connects.
Hopefully what I've described above makes sense?
E.