FB_BA_SwiHys2P

The function block FB_BA_SwiHys2P is a two-point switch with adjustable hysteresis and hysteresis offset.

A general function block enable can be implemented at input bEn. If the function block is locked, the output bQ is FALSE. The setpoint for the two-point switch is connected at input fSp. The control direction of the function block depends on the input variable bActn.

The active switching points result from the setpoint, the hysteresis and the hysteresis offset. They are output at fSwiHi and fSwiLow.

The upper switching point is given by fSp + fHys/2 + fHysOffs.
The lower switching point is given by fSp - fHys/2 + fHysOffs.

If bActn TRUE, the result is direct/synchronous control direction (cooling mode).

If bActn is FALSE, the result is indirect/reversed control direction (heating mode).

Syntax

VAR_INPUT
  bEn            : BOOL;
  fIn            : REAL;
  fSp            : REAL;
  fHys           : REAL;
  fHysOffs       : REAL;
  {attribute 'parameterUnit':= 's'}
  nDlyOn   : UDINT;// (0..BAComn_Global.udiMaxSecInMilli) switch-on delay (in [s])
  {attribute 'parameterUnit':= 's'}
  nDlyOff  : UDINT;// (0..BAComn_Global.udiMaxSecInMilli) switch-off delay (in [s])
  bActn          : BOOL;
END_VAR
VAR_OUTPUT
  bQ                 : BOOL;
  fSwiHi             : REAL;
  fSwiLow            : REAL;
  {attribute 'parameterUnit':= 's'}
  nRemTiDlyOn  : UDINT;// switch-on delay countdown (in [s])
  {attribute 'parameterUnit':= 's'}
  nRemTiDlyOff : UDINT;// switch-off delay countdown (in [s])
END_VAR

Inputs

Name	Type	Description
bEn	BOOL	General enable of the function block.
fIn	REAL	Input value
fSp	REAL	Setpoint input
fHys	REAL	Hysteresis
fHysOffs	REAL	Hysteresis offset
nDlyOn	UDINT	Start-up delay [s]
nDlyOff	UDINT	Switch-off delay [s]
bActn	BOOL	Control direction

Outputs

Name	Type	Description
bQ	BOOL	Output
fSwiHi	REAL	Upper switching point
fSwiLow	REAL	Lower switching point
nRemTiDlyOn	UDINT	Remaining time of the start-up delay [s].
nRemTiDlyOff	UDINT	Remaining time of the switch-off delay [s].

Requirements

Development environment	Required PLC library
TwinCAT 3.1 4024.56	Tc3_BA2_Common from V2.2.23.0