IAxis.DigitalCamSwitch method

Uses an axis' position to control a switch that triggers a digital output. When an axis reaches a certain position, a switch is turned on or off. A switch can be controlled by a forward and backward movement of an axis.

Namespace: IntervalZero.KINGSTAR.Base.Class

Assembly: IntervalZero.KINGSTAR.Base.Class (in IntervalZero.KINGSTAR.Base.dll) Version: 4.4.0.0

Syntax

void DigitalCamSwitch(
       IList<McCamSwitch> switches,
       IList<McOutput> outputs,
       IList<McTrack> tracks,
       uint enableMask,
       McSource valueSource
)

Sub DigitalCamSwitch(
       switches As IList(Of McCamSwitch),
       outputs As IList(Of McOutput),
       tracks As IList(Of McTrack),
       enableMask As UInteger,
       valueSource As McSource
)

Parameters

switches

Type: IList<McCamSwitch>

Controls the switching actions. The track numbers need to be in order.

outputs

Type: IList<McOutput>

Selects which digital output will be controlled by the corresponding track.

tracks

Type: IList<McTrack>

Adds the compensation time and hysteresis to the switches on a track. TrackNumber is defined in Switches.

enableMask

Type: uint

Enables the different tracks. This parameter is 32 bits of BOOL. The corresponding track in the track array is enabled when its BOOL value is set to one.

valueSource

Type: McSource

Defines the source for axis values. For example, positions:

• mcCommandedValue, mcSetValue – synchronization on set value. We suggest you use these settings.
• mcActualValue – synchronization on actual value. This setting may not be stable.

Remarks

• McCamSwitch is a vendor-specific structure that defines switches for digital cam.
• McOutput is a vendor-specific structure linked to the (physical) outputs. If you are using your servo drive's digital output (DO), you need to use the ISubsystem.AxisOutput property before the ISubsystem.Start method.
• McTrack is vendor-specific structure containing the track properties. For example, the compensation time per track (A track is a set of switches related to one output). It can also contain the reference to the output.
• This functionality is sometimes called PLS – Phase or Position or Programmable Limit Switch.

Elements within McCamSwitch Class

Elements within McTrack Class

This definition of a cam has a start and an end position, so the user can define each single cam, which has a FirstOnPosition and a LastOnPosition (or time). This function is similar to a mechanical cam but has the additional advantages that the outputs can be set for a certain time, and to give it a time-compensation and a hysteresis.

CamSwitchMode: It can be position or time.

Duration: Time, the output of a time cam is ON. The time compensation (OnCompensation and OffCompensation) can be positive or negative. Negative means the output changes before the switching position is reached.

Hysteresis: This parameter avoids the phenomenon where the output continually switches if the axis is near the switching point and the actual position is jittering around the switching position. Hysteresis is part of McTrack, which means that a different hysteresis is possible for each track.

Example of McCamSwitch

Example of McOutput

Example of an I/O module

The figure below uses the values from the example of McCamSwitch above. It uses neither On/OffCompensation nor Hysteresis. This is the behavior of the outputs, when the axis is moving continuously in the positive direction.

DigitalCamSwitch – Positive Direction

Positive Direction: Behavior of the Outputs

TrackNumber 1 (Switch01, 02, 03) is mapped to McOutput[1] and TrackNumber 2 (Switch04) is mapped to McOutput[2]. When Switch01, Switch02, and Switch03 are triggered, the second output (Output 1) on the first I/O module (Index 0) is turned on. When Switch04 is triggered, the third output is turned on (Output 2).

Example of On/Off Compensation

This example uses OnCompensation -125ms and OffCompensation +250ms.

The figure below shows the behavior of the outputs, when the axis is moving continuously in the negative direction without On/OffCompensation and without Hysteresis.

DigitalCamSwitch – Negative Direction

Negative Direction: Behavior of the Outputs

EnableMask

EnableMask is an uint parameter that contains 32 bits. Each bit is a BOOL value that controls an output. An output is enabled or disabled by setting its corresponding bit TRUE or FALSE. For example, bit 0 controls McOutput[0] and bit 1 controls McOutput[1]. If bit 0 and 1 are TRUE, their outputs are enabled, which means their outputs will be turned on when their corresponding switches are triggered; if they are FALSE, their outputs are disabled, which means their outputs won't be turned on even if their corresponding switches are triggered.

Example of McOutput

Example 1 of EnableMask Bits

Bit 0, 1, and 2 are TRUE, which means Output 0, 1, and 2 are enabled. The outputs are turned on when their corresponding switches are triggered.

Positive Direction: Behavior of the Outputs

Example 2 of EnableMask Bits

Bit 0 and 2 are TRUE, which means Output 0 and 2 are enabled. Only these two outputs are turned on when their corresponding switches are triggered.

Positive Direction: Behavior of the Outputs

Example 3 of EnableMask Bits

All bits are FALSE, which means all outputs are disabled. No outputs are turned on even if their corresponding switches are triggered.

Positive Direction: Behavior of the Outputs

See also

IAxis Interface

IntervalZero.KINGSTAR.Base.Class Namespace