Using logic gate to inhibit heating

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I thought I'd have a play with the new General Logic object and when reviewing my heating set up yesterday I spotted an opportunity.
Initially the dining room was set to inhibit if the backdoor was open:

dining-room-hvac-connectivity.png

but it occurred to me that it was a little unfair to turn off the heating if the kitchen door was closed when the backdoor was open. Multiple entries can be added to the inhibit list, but they would act as a logical-OR, I needed an AND.

So I added a general logic object to the dining room, opened up it's behaviour and added a gate:

logic-item.png
(these images are clickable to see the full-sized versions)

As you can see, I set up the door states as the inputs and gave a usable name to the output. You can also see that the current state of the doors is shown labelled on the gate and the resulting output. This realtime animation is common in many areas of Cortex and is really useful. Just to prove the point (and the logic) I opened the backdoor*:

logic-item-2.png

Excellent, the AND gate works. So close that and we see the new Gate in the General Logic object:

logic-behaviour.png

Note that you are not adding a single gate object, but that the object can contain many gates. This wakens old memories of HILO (probably), a logic simulator where you built up netlists by defining the gates and named their inputs and outputs to connect them. At least, I'm assuming that is how this would work, because I've not tried it. I wonder if it detects feedback logic ?

And finally I replaced the inhibit input in the HVAC behaviour with the output from the new gate:

hvac-behaviour.png

Heating Inhibit with General Logic? Done.

with apologies to Gordon Ramsay. 

* actually I simulated opening it because I didn't want to run round the house.

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This page contains a single entry by David published on January 28, 2008 8:35 PM.

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