FB_CTRL_nPOINT
The function block provides an n-point transfer element in the functional diagram.
Behaviour of the output:
Data array for the example:
The value of the array with index (1,1), that is the left-hand value in the first row, can be freely selected, because it is not evaluated.
VAR_INPUT
VAR_INPUT
fSetpointValue : FLOAT;
fActualValue : FLOAT;
fManValue : BOOL;
eMode : E_CTRL_MODE;
END_VAR
fSetpointValue : Set value of the controlled variable.
fActualValue : Actual value of the controlled variable.
fManValue : Input whose value is output in manual mode.
eMode : Input that specifies the block's operating mode.
VAR_OUTPUT
VAR_OUTPUT
fOut : nPOINT_CTRL_TABLE_ELEMENT;
eState : E_CTRL_STATE;
eErrorId : E_CTRL_ERRORCODES;
bError : BOOL;
END_VAR
fOut : Output of the n-point element.
eState : State of the function block.
nErrorID : Returns the ADS error number when the bError output is set.
bError: Becomes TRUE, as soon as an error occurs.
VAR_IN_OUT
VAR_IN_OUT
stParams : ST_CTRL_nPOINT_PARAMS;
END_VAR
stParams : Parameter structure of the n-point element. This consists of the following elements:
TYPE
ST_CTRL_nPOINT_PARAMS :
STRUCT
tCtrlCycleTime : TIME := T#0ms; (*
controller cycle time [TIME] *)
tTaskCycleTime : TIME := T#0ms; (* task
cycle time [TIME] *)
pDataTable_ADR : POINTER TO
nPOINT_CTRL_TABLE_ELEMENT := 0;
nDataTable_SIZEOF : UINT := 0;
nDataTable_NumberOfRows : UINT := 0;
fHysteresisRange : FLOAT; (* range of
the hysteresis loop *)
END_STRUCT
END_TYPE
tCtrlCycleTime : 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 : 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.
pDataTable_ADR : Address of the data table.
nDataTable_SIZEOF : Size of the data table in bytes.
nDataTable_NumberOfRows : Number of rows in the data table.
fHysteresisRange : Hysteresis range, see image above. The hysteresis range functions as described for FB_CTRL_2POINT.