Related data and inputs
The related data and inputs include the following items:
- Operational space temperature (OprST)
- Space temperature source (STSrc)
- Network override space temperature (NetST) communicated input on FC bus
- Net sensor space temperature value to SA bus
- Space temperature input (ST) to ST and COM
- Return air temperature input (RAT) to RAT terminals.
- Net sensor calibration (NS-Calibration) applies an offset to the net sensor space temperature.
Operation
The operational space temperature (OprST) uses the assigned priority levels for inputs ranked from highest to lowest in the following order:
- Network override space temperature (NetST)
- Net sensor space temperature value Note: If multiple sensors are connected, the average value is used.
- Space temperature input (ST)
- Return air temperature input (RAT)
If the input in use becomes invalid, operational space temperature (OprST) reverts to the next highest priority input.
When Single Setpoint mode is enabled, the control automatically determines if it is in heating or cooling mode. If the zone temperature exceeds the Common Setpoint, cooling or heating (depending on mode of operation) are initiated. The control changes between heating and cooling mode if the zone temperature exceeds the Common Setpoint +/- the Auto Changeover.
The space temperature source (STSrc) describes the input in use for the operational space temperature (OprST), and the indications include the following items:
- BAS Override
- Indicates the network override space temperature (NetST)
- Network Sensor
- Indicates a NetSensor
- Local Input
- Indicates a space temperature input (ST)
- Return Air Temp
- Indicates the return air temperature (RAT)
- Unreliable
- Indicates no valid input is available for the operational space temperature (OprST) and the control functions that use the OprST are not permitted
The network override space temperature is used if a value is set or communicated within the last 15 minutes. If 15 minutes pass without a communicated value, the UI displays Value Timed Out and the next highest priority input is used.
The net sensor space temperature value is used after approximately 30 seconds from the time a net sensor with space temperature capability is connected to the SA Bus.
Space temperature input is used if the temperature sensor is connected to the ST and COM terminals.
Return air temperature input is used if the temperature sensor is connected to the RAT terminals.