FB_BA_SlidingLimitCtrl

Function block for monitoring a floating setpoint.

The input bEn is used for enabling the function block.

To check the function of a control system, the actual value is compared with the setpoint of the controlled system.

If the deviation of setpoint and actual value is within the tolerance range rHys, then the control is OK. If the actual value deviates from the setpoint by an amount outside this tolerance range over a longer period of time, the timer udiDelay_sec is started. After the timer has expired, if the control deviation is permanent, either the output bLowLimit or bHighLimit TRUE of the function block outputs a message.

VAR_INPUT

bEn          : BOOL;
rW           : REAL;
rX           : REAL;
rHys         : REAL;
udiDelay_sec : UDINT;

bEn: Function block enable.

rW: Setpoint.

rX: Actual value.

rHys: Hysteresis.

udiDelay_sec: Output response delay [s]. Internally limited to values between 0 and Const.udiTiSec.

VAR_OUTPUT

bHighLimit         : BOOL;
bLowLimit          : BOOL;
rHighLimit         : REAL;
rLowLimit          : REAL;
udiRemTiDelay_sec  : UDINT;

bHighLimit: Upper limit value reached.

bLowLimit: Lower limit value reached.

rHighLimit: Output of the upper limit value.

rLowLimit: Output of the lower limit value.

udiRemTiDelay_sec: Time remaining after a limit value has been exceeded until either the output bHighLimit or bLowLimit responds.

Requirements