Valve timing help

Hello, curious if anyone can offer me a little assistance with a project. I'd appreciate it. I'm getting all caught up in my timers and sequences and have lost focus.....

RSLogix5000 - ladder or FB, take your pick.

I have 2 valves in parellel to operate as a dual timer, off/on cyclic operation; 1 hour closed, 30 seconds open. They just can't be open at the same time and should probably wait a several minutes between each other. They feed into the same drain path, but the drain cannot support the flow of both valves open and there's the potential to backfill the other valve as the supply pressures may differ.

The operator has the ability to select each valve to Auto and Manual independantly of each other. Manual mode will allow the operator to open/close a valve at their discretion, but again, not with the other valve open. Both valves can be in manual, auto, or any combination. Placing the valve(s) back into auto should be seamless and will restart the timing sequence.

Welcome to the site
If you need to protect against both valves openning together
Handle this one seperately - this way regardless which one is singled the the other must be closed.
As fas as sequencing - I would suggest using a step style program
I am a little bit busy now - I can post something later

My initial stab at it was using Function Block and a pair of on-delay timers. One with PRE of 1 hour (off timer), and using DN to EN the second timer for 30 seconds (on timer). I used the TT of the second timer (on timer) to open the valve, the DN bit reset both timers and the sequence restarted.

Okay, so I added the second valve timer set, fine. But then tried to determine whether to lock out the second timer from the start time, or the time from when the valve closed, tying them together with BAND, etc., etc. I can get them to time correctly, but if an operator upsets the sequence by going to manual the whole thing falls apart....

I dunno, I'm pretty rusty at this to be honest.

if you write a step sequence - assuming it is not important as to which valve starts.
- 10 = start open valve 1
- 20 = close valve 1
- 30 = delay valve 2 signal
- 40 = open valve 2
- 50 = close valve 2
- 60 = delay open valve 1
- 60 = move Value to 10

similar for manual

The step sequence would work assuming that's the order that will be used all the time. What I can't get is how the operator can select only 1 valve to go to manual, open/close it at will, while also ensuring the second valve doesn't open at the same time and without disrupting it's timing sequence, then placing the valve back to Auto and resume the original 1hr/30min timer (delayed from the first valve of course).

So, if the individual valve sequence is too long for some reason, the op can override auto. There's no requirement to sequence the valves together, only apart if that makes any sense.

there are many ways of doing this
Seperately sequence the manual - even use a different routine
If valve 2 is open when you switch back to Auto then simply move the Value
40 0r 50 to sart the sequence from there = too easy