Homing mode for multi-turn absolute encoder and limited axis

[austin.carpenter]

Hello Nicolò,

@nrampinelli01

2. Why is it better to choose the restore position when the encoder range is smaller than the movement range?

To speed up the startup of the axis. If the axis limits are within the encoder range, then there is a 1:1 mapping between encoder positions and valid axis positions. Just by reading the encoder, and using a stored homing offset, the physical position is always known.

I am still confused about this aspect. If the encoder range is less than the movement range, it means that the axis limits are not contained in the encoder range, so the 1:1 relationship is only true if there is no movement more than half of the encoder counting range, right? So is it better to choose the restore position mode because it is based on the assumption that no movement greater than half the encoder counting range is made even when the 1:1 relationship cannot be maintained? Or is the reason that in this case there is no difference in using the restore position mode compared to the absolute mode, and that you can therefore use the restore position mode to recover the position automatically?

Sorry, I misread the original question #2 and didn’t answer your actual question. You can disregard my previous attempt at an answer, it’s just wrong .

Okay, let me try again .

2. Why is it better to choose the restore position when the encoder range is smaller than the movement range?

I assume you are referring to the section in the decision tree marked with the blue box below.

The reason to use the restore position is that it tracks encoder rollovers while power is on and can compensate for them when the power switches back on again. The restore position includes the limitation that you can’t move more than 50% of the full encoder rollover while the power is off but will be able to track the encoder rollovers, unlike Home_Absolute/Absolute_Correction.