FB_BA_SwiHys2P

Functional description

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 rSp. The direction of action 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 rSwiHi and rSwiLo.

• The upper switching point results from rSp + rHys/2 + rHysOffs.
• The lower switching point results from rSp + rHys/2 + rHysOffs.

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

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

VAR_INPUT

bEn      : BOOL;
rIn      : REAL;
rSp      : REAL;
rHys     : REAL;
rHysOffs : REAL;
bActn    : BOOL;

bEn: general enable of the function block

rIn: input value

rSp: setpoint input

rHys: hysteresis

rHysOffs: hysteresis offset

bActn: control direction

VAR_OUTPUT

bQ      : BOOL;
rSwiHi  : REAL;
rSwiLo  : REAL;

bQ: output

rSwiHi: upper switching point

rSwiLo: lower switching point

Requirements