HVAC_Coil (FB)¶

Functionality¶

HVAC_Coil provides a control strategy for a HVAC (heater / cooler) coil taking into account:

• differential pressure monitoring

• fan request

The fan is requested if:

• it is enabled (xEnable = TRUE)

• differential pressure monitor is detecting proper differential pressure (xDifferentialPressureMonitor = TRUE)

• setpoint reaches/exceeds fan request threshold (rSetpt >= rFanReqTreshold)

The fan request involves a stop delay.

In case the differential pressure monitor is not detecting proper differential pressure, this is signaled by xError=TRUE / eErrorID=HardwareError.

InOut:

Scope	Name	Type	Initial	Comment
Input	xEnable	BOOL	TRUE	Enable
	rSetpt	REAL	0.0	Setpoint, 0..100(%)
	rFanReqTreshold	REAL	0.0	Fan request threshold, 0..100(%)
	xDifferentialPressureMonitor	BOOL	TRUE	Differential pressure monitor - TRUE => signaling proper differential pressure
	tFanStopDelay	TIME	TIME#0ms	Fan stop delay
	xReset	BOOL	FALSE	Reset
	itfDateTimeProvider	Util.IDateTimeProvider	Globals.g_dtpDateTimeProvider	Source for the current date and time information in milliseconds since 1.1.1970 00:00:00.000
Output	xOn	BOOL		Coil is switched on.
	xFan	BOOL		Fan request
	xError	BOOL		Error indication
	eErrorID	Error		Error ID

Methods:

SetError

Structure: