FastHeating

FastHeating (FB)

FUNCTION_BLOCK FastHeating

Short description

Activation of a fast heating mode (controlled variable: room temperature) Typical application: Activation of the fast heating mode during operation of an air handling unit

Representation

Function description

General

This function block controls the activation of the fast heating mode ( xEn = TRUE ) by comparing the room temperature rRoomTemp with the room setpoint temperature rSetPtTemp when the ventilation system is active ( xRegAHU = TRUE ). The fast heating mode can also be activated independently via the input xCoolOutProtectionEn activated.

Enable / disable of the fast heating mode xEn

xReqAHU	rRoomTemp	xCoolOutProtection	xEn	Notes
FALSE	X	FALSE	FALSE	Fast heating mode via ventilation system and input locked
TRUE	> rSetPtTemp + rSwitchOffPoint	FALSE	FALSE	Fast heating mode via room temperature locked
TRUE	< rSetPtTemp + rSwitchOnPoint	FALSE	TRUE	Fast heating mode via room temperature enabled
X	X	TRUE	TRUE	Fast heating mode via input enabled

Legend: X = don't care

CODESYS

InOut:

Scope	Name	Type	Initial
Input	rSetPtTemp	REAL
Input	rRoomTemp	REAL
Input	xReqAHU	BOOL
Input	xCoolOutProtectionEn	BOOL
Output	xEn	BOOL
Input Const	rSwitchOffPoint	REAL	-1
Input Const	rSwitchOnPoint	REAL	-2.5