HVAC system IO

[ICS-GS]

Hi guys,

just a quick question regarding the in-built system IO for HVAC controls
with regard to the zones, and the option to select multiples of them.

is (GetBoolIBSystemIO("HVAC Plant Heating", 1, HVACZone123) = ON)

the same as
(GetBoolIBSystemIO("HVAC Plant Heating", 1, HVACZone1) = ON) or
(GetBoolIBSystemIO("HVAC Plant Heating", 1, HVACZone2) = ON) or
(GetBoolIBSystemIO("HVAC Plant Heating", 1, HVACZone3) = ON)


OR

(GetBoolIBSystemIO("HVAC Plant Heating", 1, HVACZone123) = ON)

the same as
(GetBoolIBSystemIO("HVAC Plant Heating", 1, HVACZone1) = ON) and
(GetBoolIBSystemIO("HVAC Plant Heating", 1, HVACZone2) = ON) and
(GetBoolIBSystemIO("HVAC Plant Heating", 1, HVACZone3) = ON)

or none of the above

Thanks

Grant

[Darren]

It is not actually either of the above. From the help file topic "HVAC App In-built System IO":

It is not possible for a component to show more than one value. Hence if more than one zone is selected for a component, the data displayed is generally the first zone in the list which is being serviced (i.e. it is enabled and the damper is open). If there are no serviced zones, the first active zone will be used. If there are no active zones, the first zone will usually be used. So, for example, if a Component is showing the temperature of Zones 1, 2 and 3 and Zone 1 is switched off, then the temperature of Zone 2 will be displayed.

[ICS-GS]

thanks darren,

so what you are saying is that i would have to use all 4 statements:

123 or
1 or
2 or
3 then...

to be able to determine if the heating is on in any zone?
Given that i have 4 pages to control heating:
1. for whole of house (123) which sets all zones to same temp and mode
2. for zone 1 only (1)
3. for zone 2 only (2)
4. for zone 3 only (3)

Is this correct?

Thanks

Grant

[Darren]

This is not quite right. The HVAC Plant Heating in-built system IO tells you whether the plant itself is currently heating, not whether an individual zone is heating. The plant can only be doing one thing at a time (ie. heating or not heating) so you can just use HVACZone123 to find out if the plant is currently heating.

A zone will be heating if the plant is heating and the zone damper is open.

[ICS-GS]

i don't disagree, but it gives me the option to select individual zones... or collectively as a group of zones... don't tell me i've become dave byron, finding issued with software:eek: