Is the for the function for position reconstruction after the switching on the Setting under AxisRef Subindex 082 required?
Why go to the power-on, despite using an absolute encoder, the reference lost (HomePosAvailable = False), if under subindex 082 a small value and not zero set ?
Answer;
Absolute value encoder, Position reconstruction;
The position reconstruction function after power-up works
independently of parameter subindex 082 of the motion axis (AxisRef).
Recommendation
- Subindex 082 = 0 (Default) Leave unchanged or
- Set subindex 082 to a higher value so that the reference is not reset by even the smallest changes in position.
Background:
As has been shown in practice , the function of parameter subindex 082 is often misunderstood by users and very small values are set under Sub 082. It is mistakenly assumed that this will increase the accuracy of the reconstructed actual position, but this is not the case!
The accuracy of the reconstructed actual position depends not on the setting under subindex 082. The implemented position reconstruction method ensures high accuracy regardless of this, even if themotor shaft has been moved while switched off.
The only condition that must be met is that the encoder/motor shaft must not have moved more than half the display range of the absolute encoder used when switched off, relative to the actual position when switched off.relative to the actual position when switched off.
Display ranges
- Single-turn absolute encoder +/- 180°
- Absolute encoder Multiturn +/- 2048 encoder revolutions
Due to the principle involved, iinside the device, a movement of the encoder / motor shaft in the switched-offstate, beyond +/- the half of the display range of the absolute encoder used, cannot be detected or checked!
Function Subindex 082:
This is an additional monitoring function:
About subindex 082 the range of permissible movement can be narrowed down when the device is switched off, if this is necessary for the application itself.movement when switched off be narrowed down if this is necessary for the application itself.
If the position tolerance set under 082 is exceeded, the reference is reset as a reaction and must be referenced again.
