FB_CTRL_D

FB_CTRL_D 1:

The function block provides a DT₁ transfer element (a real D-element) in a functional diagram.

Transfer function (continuous)

VAR_INPUT

VAR_INPUT
    fIn              : FLOAT;
    fManSyncValue    : FLOAT;
    bSync            : BOOL;
    eMode            : E_CTRL_MODE;
END_VAR

Name	Type	Description
fIn	FLOAT	Input of the D element
fManSyncValue	FLOAT	Input to which the D-element can be synchronized, or whose value is present at the output in Manual Mode.
bSync	BOOL	A rising edge at this input sets the D-element to the value "fManSyncValue".
eMode	E_CTRL_MODE	Input that specifies the operation mode of the function block.

VAR_OUTPUT

VAR_OUTPUT
    fOut        : FLOAT;
    eState      : E_CTRL_STATE;
    eErrorId    : E_CTRL_ERRORCODES;
    bError      : BOOL;
END_VAR

Name	Type	Description
fOut	FLOAT	Output of the D element
eState	E_CTRL_STATE	State of the function block
eErrorId	E_CTRL_ERRORCODES	Supplies the error number when the output `bError` is set.
bError	BOOL	Becomes TRUE, as soon as an error occurs.

VAR_IN_OUT

VAR_IN_OUT
    stParams    : ST_CTRL_D_PARAMS;
END_VAR

Name	Type	Description
stParams	ST_CTRL_D_ PARAMS	Parameter structure of the D-element

stParams consists of the following elements:

TYPE ST_CTRL_D_PARAMS:
STRUCT
    tCtrlCycleTime  : TIME  := T#0ms;
    tTaskCycleTime  : TIME  := T#0ms;
    tTv             : TIME  := T#0ms;
    tTd             : TIME  := T#0ms;
    fOutMaxLimit    : FLOAT := 1E38;
    fOutMinLimit    : FLOAT := -1E38;
END_STRUCT
END_TYPE

Name	Type	Description
tCtrlCycleTime	TIME	Cycle time with which the control loop is processed. This must be greater than or equal to the TaskCycleTime. The function block uses this input value to calculate internally whether the state and the output values have to be updated in the current cycle.
tTaskCycleTime	TIME	Cycle time with which the function block is called. If the function block is called in every cycle this corresponds to the task cycle time of the calling task.
tTv	TIME	Differentiation time constant
tTd	TIME	Damping time constant
fOutMaxLimit	FLOAT	Upper limit to which the output of the D-element is restricted.
fOutMinLimit	FLOAT	Lower limit to which the output of the D-element is restricted.