MC_OverrideFilter

The function block MC_OverrideFilter can be used to convert an unfiltered override value consisting of digits (e.g. a voltage value of an analog input terminal) into a filtered override value that matches the cyclic axis interface (PlcToNc) (DWORD in the range 0...1000000). This filtered override is also available in percent (LREAL in the range 0...100%).
The raw input value is limited to a validity range by LowerOverrideThreshold and UpperOverrideThresholdauf, and implemented as parameterisable steps (resolution) (OverrideSteps). After each override change at the output of the FB, a minimum recovery time is awaited internally (OverrideRecoveryTime) before a new override value can be accepted. The only exceptions are the override values 0% and 100%, which are always implemented without delay for safety reasons.

VAR_INPUT

VAR_INPUT
    OverrideValueRaw        : DINT;
    LowerOverrideThreshold  : DINT  := 0;        (* 0...32767 digits *)
    UpperOverrideThreshold  : DINT  := 32767;    (* 0...32767 digits *)
    OverrideSteps           : UDINT := 200;      (* 200 steps => 0.5 percent *)
    OverrideRecoveryTime    : TIME  := T#150ms;  (* 150 ms *)
END_VAR

OverrideValueRaw: Raw, unfiltered override value (e.g. a voltage value of an analog input terminal).

LowerOverrideThreshold: The lower threshold for the raw override value.

UpperOverrideThreshold: The upper threshold for the raw override value.

OverrideSteps: The specified steps (override resolution).

OverrideRecoveryTime: Minimum recovery time, after which a new filtered override value is placed on the output. The override values 0% and 100% are implemented without delay.

VAR_OUTPUT

VAR_OUTPUT
    OverrideValueFiltered   : DWORD;  (* 0...1000000 counts *)
    OverridePercentFiltered : LREAL;  (* 0...100 % *)
    Error                   : BOOL;
    ErrorId                 : UDINT;
END_VAR

OverrideValueFiltered: The filtered override value in digits (the data type matches the override in the cyclic axis interface 0..1000000).

OverridePercentFiltered: The filtered override value in percent (0..100%).

Error: Becomes TRUE, as soon as an error occurs.

ErrorID : If the error output is set, this parameter supplies the error number.

Possible error number	Possible causes
MC_ERROR_PARAMETER_NOT_CORRECT	OverrideSteps <= 1 LowerOverrideThreshold >= UpperOverrideThreshold

Requirements

Development Enivironment	Target System	PLC Libraries to include
TwinCAT v2.8 Build > 739	PC (i386)	TcMC.Lib