What would be the best way to do the following...

[Mudguppie]

...when at home the thermostats follow a pre-defined schedule but when the perimeter alarm is set to be away, the thermostats are set back. When the alarm is set to off then the thermostats return to the non-setback temeperatures according to the current schedule. All the hardware is in place, I just need some programming help. Thanks. ~Robert

[ewelin]

How do you change between home and away, do you use the built in Mode option or are you just using schedules? What about setting and disabling your alarm? What sort of schedule do you have for your thermostat currently? Does it change at all or during the day if you're home, or do you only want the set point to adjust when the mode/alarm adjusts?

Without knowing too much about your automation setup, I would suggest that you use a create a program to adjust the setpoint and then have that program called via the method you use to change schedules/alarm status. So if you have a program which disables your alarm, have it call a program which checks the current schedule status and sets the setpoint according to the schedule.

Hopefully that gives you some guidance.

[Mudguppie]

I don't currently use schedules (they're disabled) because they'll override the setback that occurs when the alarm is set. Currently, when I set the alarm it just turns off the HVAC system but it could just as easily enable the setback. The schedule, when enabled, will adjust the temperature setpoint during the day. When the alarm is set to away mode the setback occurs via a program. When the alarm is set for stay mode, it adjusts the temperature for the night setting. What you describe is what I want to accomplish but I cannot see any way to do it. If I use the set schedule command and set it to an away schedule which would essentially turn off any setpoint changes, when I return and enable the normal schedule will it then change the setpoint to what the temperature would be had the schedule been enabled all along?

What I'm asking is if I get home at 5:30 and the temp was set to 68 because of the setback but the normal schedule would have the temp at 74 at say 4:30, if the program then reenabled the normal schedule would it then immediately change the setpoint to 74 even though the time for the change has passed?

[KHarms]

The answer to your question is no. A schedules doesn't "catch up" when it is made the current schedule.

Normally this sort of stuff doesn't really matter much - for example when it is lighting. Clearly though sometimes it does and HVAC is a "big dog" in this regard. What I would do is to create programs that do what you want. Tie those programs to whatever it is that you do when you get home. Remember that you can have more than one program triggered off the same event. This will make it simpler to modularize your work.