FB_CTRL_MOVING_AVERAGE

FB_CTRL_MOVING_AVERAGE 1:

The function block provides a moving average filter in the functional diagram.

The arithmetic mean value of the last "n" values is calculated.

The programmer must create an array "ARRAY [1...n] of FLOAT" in the PLC, in which the function block can store the internally required data.

Inputs

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

Name	Type	Description
fIn	FLOAT	Input value for the moving average filter
fManSyncValue	FLOAT	Input value to which the moving average filter can be set, or that is issued at the output in manual mode.
bSync	BOOL	A rising edge at this input sets the moving average filter to the value "fManSyncValue".
eMode	E_CTRL_MODE	Input that specifies the operation mode of the function block.
bHold	BOOL	A TRUE at this input will hold the internal state (and therefore also the output) constant at its current value, independently of the input value.

Outputs

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

Name	Type	Description
fOut	FLOAT	Output of the moving average filter
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.

Inputs/ outputs

VAR_IN_OUT
    stParams              : ST_CTRL_MOVING_AVERAGE_PARAMS;
END_VAR

Name	Type	Description
stParams	ST_CTRL_MOVING_AVERAGE_PARAMS	Parameter structure of the moving average filter

stParams consists of the following elements:

TYPE
ST_CTRL_MOVING_AVERAGE_PARAMS:
STRUCT
    tCtrlCycleTime        : TIME := T#0ms;
    tTaskCycleTime        : TIME := T#0ms; 
    nSamplesToFilter      : UINT;
    pWorkArray_ADR        : POINTER TO FLOAT := 0;
    nWorkArray_SIZEOF     : UINT     := 0;
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.
nSamplesTo Filter	UINT	The number of values, "n", whose arithmetic mean value is calculated.
pWorkArray_ ADR	POINTER TO FLOAT	The address of the array where the input values are temporarily stored.
nWorkArray_ SIZEOF	UINT	Size of the `WorkArrays`