Homing

Example video of hard-stop homing with VSD-XE drive (and some random motion with absolue positioning).

Homing is a method for acquiring the absolute zero position of a mechanical axis to a known absolute position.

For example if linear axis is equipped with an incremetal feedback device, then position of the axis is not known by the machine after system power-on. To acquire absolute position, axis must be driven to known point (home point) where the position counter is zeroed.

Homing methods

Most of Granite Devices drives support homing axis by combining different optional motion elements as a sequence:

1. Move axis to search a home switch or mechanical end of travel (a.k.a. hard-stop homing), direction and speed of motion is selectable.
2. Then optionally move axis to user defined amount in used defined direction, and start search of home switch or mechanical end of travel again. This allows approaching the home always from the same direction eliminating the home switch hysteresis. The second approach is done at reduced 1/4 speed for higher positional repeatability. (1)
3. Then optionally move axis to search feedback device index pulse. Index pulse provides very high position repeatability. Direction is selectable.
4. Then optionally move axis to offset position. In practice user can enter a position value to drive where axis is driven after all previous homing functions are done.
5. Then optionally set absolute position travel limits (soft limits). User may also set upper & lower bounds for position setpoint to possibly elimiate the need of axis limit switches.

Homing is configurable through drive configuration software. The homing sequence can be saved in the drive and can be set to start automatically after power-on or on user start homing command.

(1) This step is supported only by selected drive models. Currently it is supported by IONI Pro series.

See also

• Hard-stop homing

In no event the Product Information or parts hereof shall be regarded as guarantee of conditions or characteristics. The Product Information or any part thereof may also not be regarded as a warranty of any kind. No liability of any kind shall be assumed by Author with respect to Product Information or any use made by you thereof, nor shall Author indemnify you against or be liable for any third party claims with respect to such information or any use thereof.

As content of this Wiki may be edited by user community, Granite Devices Oy or it's affiliates do not take any responsibility of the contents of this Wiki. Use information at your own risk. However, Granite Devices staff attempts to review all changes made to this Wiki and keep information trustworthy.

Without written consent, Granite Devices' Products or Intellectual Property shall not be used in situations or installations where living beings, material property, or immaterial property could be harmed by the operation, features or failures of Product. Products may only be used in a way where hazards like moving parts, electric shock, laser radiation, or fire can't be realized even if the content of this Wiki would suggest otherwise.