MC_AxUtiSlewRateLimitter_BkPlcMc (from V3.0)
The function block generates a rise-limited ramp.
Inputs
VAR_INPUT
fInput: LREAL:=0.0;
fCycletime: DINT:=0;
fMaxRate: DINT:=0;
END_VAR
Name | Type | Description |
|---|---|---|
fInput | LREAL | The raw value of the parameter to be filtered. |
fCycletime | DINT | [s] The cycle time of the calling PLC task in seconds. |
fMaxRate | DINT | The magnitude of the maximum permitted rate of change at the output as change per second. |
Outputs
VAR_OUTPUT
fOutput: LREAL:=0.0;
bError: BOOL:=FALSE;
nErrorId: UDINT:=0;
END_VAR
Name | Type | Description |
|---|---|---|
fOutput | LREAL | [1/s] The filtered value. |
bError | BOOL | This output indicates problems with the transferred parameters. |
nErrorId | UDINT | In the event of an error, coded error information is output here. |
Behavior of the function block
With each call the function block checks the transferred values for fCycletime and fMaxRate. If the values are incorrect, the system responds with bError and coded information in nErrorId. Otherwise, the difference between Input and Output is determined with each call. If the magnitude of this difference is less than or equal to fMaxRate * fCycletime, the value of Input is used directly as fOutput. Otherwise, fOutput is changed by fMaxRate * fCycletime. The sign is selected automatically.
 | The value for fCycletime must be ≥ 0.001. Negative values are not permitted for fMaxRate. |
Input will usually be a value, which is determined and filtered based on the cycle of the axis blocks. Axis_Ref_BkPlcMc.ST_TcHydAxParam.fCycletime can be used for fCycletime here.