MC_AxRtFinishLinear_BkPlcMc (from V3.0.16)
The function block deals with the adjustment of the generated control value to the special features of the axis, taking into account a characteristic curve.
Inputs
VAR_INPUT
EnableLinearisation: BOOL;
ValveTable: POINTER TO LREAL:=0;
ValveTableLowIdx: INT:=0;
ValveTableHighIdx: INT:=0;
END_VAR
Name | Type | Description |
|---|---|---|
EnableLinearisation | BOOL | TRUE at this input activates the linearization. |
ValveTable | POINTER TO LREAL | The address of the linearization table should be transferred here. If possible, this should be the ValveCharacteristicTable of an ST_TcMcAutoIdent linked to the axis. If a NULL-pointer is passed here the linearization table and the limiting indices of the ST_TcMcAutoIdent structure associated with the axis are used. If such a structure is not present, the function block shows the behavior of a MC_AxRtFinish() function block. |
ValveTableLowIdx | INT | The index of the first point in the linearization table. |
ValveTableHighIdx | INT | The index of the last point in the linearization table. If possible, this should be the ValveCharacteristicTblCount of an ST_TcMcAutoIdent linked to the axis. |
Inputs/outputs
VAR_INOUT
Axis: Axis_Ref_BkPlcMc;
END_VAR
Name | Type | Description |
|---|---|---|
Axis | Axis_Ref_BkPlcMc | Here, the address of a variable of type Axis_Ref_BkPlcMc should be transferred. |
VAR_
Outputs
UTPUT
Error: BOOL;
ErrorID: UDINT;
END_VAR
Name | Type | Description |
|---|---|---|
Error | BOOL | The occurrence of an error is indicated here. |
ErrorID | UDINT | An encoded indication of the cause of the error is provided here. |
Behavior of the function block
The function block investigates the axis interface that has been passed to it every time it is called. A number of problems may be detected:
- EnableLinearisation is FALSE.
- There is no ValveTable available.
- ValveTableLowIdx is less than 0.
- ValveTableHighIdx is less than or equal to ValveTableLowIdx.
In these cases an MC_AxRtFinish_BkPlcMc function block is called internally, and its outputs are passed on. Otherwise the table linearization for the axis is performed. Note the following special characteristics:
- The parameter for compensating the directional dependence (area ratio, gravity etc.) of the axis velocity has no effect. This compensation should be taken into account in the table.
- The parameters for compensating a kink in the characteristic curve have no effect. This compensation should be taken into account in the table.
- The parameter for the overlap compensation has no effect. This compensation should be taken into account in the table.
- A pressing power output or an offset compensation cannot be realized through a linearization. The corresponding parameters are active.
Example: Display of a linearization in the PlcMcManager:
A sample program can be found in the SampleList of the Knowledge Base. Demonstrates automatic determination of a characteristic curve with an MC_AxUtiAutoIdent_BkPlcMc function block.