FC_TPEdge

 

FC_TPEdge - General Information

Overview

Task

Record position to an event on a filed input (TouchProbe = TP); for example, register mark.

Description

Position measurement via an edge at a measured input. The used digital input must be configured as Touchprobe input before Sercos phase-up. The measurement of the position starts by calling the function. If a valid measurement result is recognized, the measurement is reported back through the CaptureOK parameter of the measured input.

NOTE: The function is "edge-triggered," meaning it is triggered once per working cycle.

The event or signal is entered in the PacDrive system at a measuring input using the measurement sensor (such as the print marker sensor).

Using the function FC_TPEdge(), the measuring input (i_stTPId), the edge (i_xPosEdge), the position source (i_stDevId), the position type (i_diParType), and the position window (i_lrLowLimit and i_lrHighLimit) is defined. If the measurement result is outside the position window, then the system discards the measurement and waits for a valid one.

When the FC_TPEdge() function is called, the status of the CaptureOk parameter of the measured input is set to FALSE and the CaptureValue parameter of the measured input is set to 0.

NOTE: If the function is called in an external event-driven task, then the priority (system priority VxWorks) of the task in which the function is called has to be >32.

NOTE: For information concerning the minimum interval between two measuring impulses (using LXM62DxS with OnboardIO), refer to "Interval between two measuring impulses".

NOTE: Shifting CaptureValue. With a speed modification, the CaptureValue moves due to delays in the system.

In order to compensate this, consider:

0 / Position: TP SensorDelay = TP HW Delay - ShaftDelay

1 / RefPosition: TP SensorDelay = TP HW Delay - ShaftRefDelay

2 / MechPosition: TP SensorDelay = TP HW Delay - ShaftDelay

3 / RefMechPosition: TP SensorDelay = TP HW Delay - ShaftRefDelay

4 / ShaftMechPosition: TP SensorDelay = TP HW Delay

5 / ShaftMechRefPosition: TP SensorDelay = TP HW Delay

NOTE: The function FC_TPEdge() may only be placed and used in Sercos Phase 4. If the function leaves Phase 4, the TouchProbes must be reactivated when Phase 4 is reached again.

Interface

Return Value

Examples

CASE diState OF
1:  

   diResult:=FC_TPEdge(
      i_stTPId:=TP.stLogicalAddress,
      i_stDevId:= Encoder.stLogicalAddress,
      i_diParType:= 0,
      i_xPosEdge:= TRUE,
      i_lrLowLimit:= -MAXX,
      i_lrHighLimit:= MAXX );
   diState:=2;
2:  

   IF TP.CaptureOk = TRUE THEN
      lrTP_Pos:= TP.CaptureValue;
      ...
   END_IF
END_CASE