Relay NOT logic

Hi, there is probably a really simple answer to this but please advise.

I don't have any logic engine available and simply want to disable (turn off) a relay output using a timer for lets say 30 minutes and have the output on for all other times.

Can someone point me in the right direction?

Cheers!

 

I am assuming you want to do this by pressing a key and not automatically at a specific time (otherwise you will need a scheduling unit like a touch screen or wise or pac).

Create a new group address called say 'Enable Relay'.
On you relay unit, select the logic tab. On a spare line select the relay channel check box and then select the new group address in the logic groups drop down. Select AND as the function.

So far whenever the 'Enable Relay' ga is set, it will be controlled normally, and when the ga is off the relay is off.

On your switch, enter the 'Enable Relay' group for the key you are using.
Go to the key functions tab and select:
short press: Off key
short release: Start
long press: idle
long release: on key

Go to the blocks tab and find the block associated with your key.
set:
recall 1 to 100%
timer to 30min
expiry to recall 1

Hey presto.

To get it going you need to set the 'enable relay' group on. That's what the long release is for. Press and hold the key and when you release it the group will be on the the relay controlled via it's normal ga.

When you give the key a short press, it turns to ga off and starts the timer. At the end of the time it executes the expiry command which is a recall to 100% (you can't have an ON command as a timer expiry for some unknown reason so that's why it's a recall to 100%).

This solution will allow you to control the relay via another ga when the timer isn't running. If you only want the relay to be controlled by the switch, just select the 'Enable Relay' ga in the main channel drop down and forget about the logic.

I guess it wasn't really a simple answer, but the best I could come up with

 

Hi Ashley, yes I did want to press a key and yes it wasn't as simple as I thought originally.

Thanks so much, works great! Maybe something that could be implemented would be an ON for a timer expiry function but the recall does the job fine.

Gotta love this forum