Groups and Triggers
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Groups and Triggers

Group Stop

In each cue, there is the option for an axis to be part of the Global Stop Group.

If any axis in this group errors, it will cause all the other axes in the group to also stop.

To add an axis to the Global Stop Group:

  • Locate the axis in the cue where you want to add it to the Stop Group.
  • Tick the Group Stop checkbox.
  • Tap the Update button, to update the cue with your changes.
The Group Stop checkbox
The Group Stop checkbox
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The Global Stop Group works on a cue by cue basis. That means it’s possible to run a second cue which takes an axis out of the Stop Group while other axes are still moving. Take extra care that you are creating the desired behaviour when programming with stop groups.
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The Global Stop Group only acts on errors and does not link axes together in a way that guaranteeing position in relation to each other. If your application required two axes to move in sync, contact Absolute Motion Control as this will need to be done at the system level.

Triggers

For each axis in a cue, there is the option to wait for a condition to be met before starting the move.

Entering trigger information
Entering trigger information

Triggers can be used to start an axis when another is at a certain position, either for creativity or for safety. For example, you might want to fire two axes together and when one is clear of the other, automatically start the second axis.

Entering the trigger information:

Triggering Axis

Select an axis from the dropdown. This is the axis that will be watched for the trigger value. It can be any axis.

An axis can also trigger itself if you run an overlays move, so it can be selected from this dropdown. See “Overlaying Moves” to understand how firing a second move over one that is already running works.

Condition

Select a condition from the dropdown. This is be the condition that the triggering value needs to be met before the move will run.

=
Equal To (IMPORTANT NOTE: see below)
!=
Not Equal To
<
Less Than
>
Greater Than
<=
Less Than or Equal To
>=
Greater Than or Equal To

<= and >= are the most commonly used conditions.

They are useful because if you have passed the trigger value then need to stop and restart a move, they will start as expected.

If you start and stop a move before you reach the trigger value, it will wait for the trigger value to be met before starting.

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Make sure you understand the effect of the trigger conditions and how they relate to the trigger value fully before using them in a move. Starting position and direction will affect how a trigger behaves.
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Equal To uses to an exact value ONLY. DO NOT use this trigger condition for positional moves as an exact value can be missed. Always use <= or >= on positional moves to ensure that the trigger will happen correctly. Use Equal To ONLY on IO axes, where the value can only be from a small range of discrete values.

Value

Enter the value here that will be used to create a condition that needs to be met in order for the axis to start.

This will usually be a position but can also be an IO value (0,1).

To add a trigger to an axis:

  • Locate the axis in the cue where you want to add a trigger.
  • Enter the Triggering Axis, the Trigger Condition and the Trigger Value in the dropdown boxes labeled Trigger.
  • Tap the Update button, to update the cue with your changes.

Advanced Triggers

Triggers can also be used as pseudo-interlocks.

For example, you might want to fire two axes as separate cues, but make sure that the second axis is definitely clear of the other before the move starts.

In this case the trigger isn’t necessarily used to trigger the start of the movement, but may provide some protection against an operator firing the second cue too early.

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Triggers MUST NOT be used in place of system level interlocks. If your application requires the use of safety interlocking this must be implemented by Absolute Motion Control at the system level.