Goal
The mappMotion Technolgy function block MpAxisBasic offers a stop feature called StopAtPosition. This feature can be used to trigger a stop, which is calculated so that it stops at a clearly defined position.
This feature is only described very sparsely in the Automation Studio help, so it makes sense to provide brief information on 2 special behaviours here.
Periodic axes
The stop process also works via the period jumps of periodic axes.
If, for example, a 360° periodic axis is stopped at position 33, this is done in the cycle that can be reached with the set delay.
Intermediate velocity
When running a stop with an active StopAtPosition, not only the values of the structure
MpAxisStopType are relevant, but also the speed of the structure
MpAxisParType.
The stop process runs in such a way that the set ramp is used to decelerate to the velocity set in the MpAxisParType. It continues to run at this speed until the position is reached at which the stop point is reached with the set deceleration.
The following print screen illustrates this behaviour.
Start velocity 500Parameter.Velocity 250Parameter.Stop.StopAtPosition.Deceleration 25Parameter.Stop.StopAtPosition.Position 33
It can be seen that the deceleration is first reduced to 250 and only then stopped.
The orange signal represents the stop command.
If the Parameter.Velocity is set to 0, the function block is stopped but never returns a Stopped.
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