Laser machine tool zero configuration

04 Sep 2021 02:58 #219570 by wang
Hello everyone

My machine tool's zero return method is like this, as shown in the figure below

Can someone tell me how I should configure it?
I can’t understand the explanation of the terms HOME_SEARCH_VEL, HOME_LATCH_VEL, HOME_USE_INDEX, HOME_SEQUENCE in the tutorial 

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04 Sep 2021 11:01 #219590 by chris@cnc
Well, I'll try to put that into simple words.
HOME_SEARCH_VEL -> Start speed when homing to the 1st switch
HOME_LATCH_VEL -> Speed for fine positioning after finding the 1st switch
HOME_USE_INDEX -> Index signal e.g. (Z phase) from encoder
HOME_SEQUENCE -> Axis logic in automatic reference mode 0-> 1-> 2 Joint0 -> Joint1 -> Joint 2 moves reference one after the other

One possibility is to use the limit+ switch as a homeswitch and set the offset a bit in front of the switch.
Saves a switch. Second, inductive sensors are very imprecise for homing.
Roller switches are a bit better about 0.1mm error.
The third possibility is then to use the index signal from the encoder.
That means first approach limit+ switch and then read the index signal.
That is very precise for e.g. Tandem axes a good and accurate choice.
We have a choice of how precisely we want to reference a machine. 
That explains why there are so many options in the INI. A bit difficult at the beginning, but very flexible in the end. I love it. 

No homing search in case of e.g. Simulator 

Only Index (Z-Phase) search in case of e.g. scale using. Note that Encoder of Servo Motors have one Index every turn.
So you will set Zero every revolution and need a second switch.

Only switch search. Could be only one e.g. the limit switch. If HOME_IGNORE_LIMITS seclect and Signal in hal to joint.home wired to.

homing with switch and Index Signal. In case of tandem axis good choice

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12 Sep 2021 02:07 #220273 by wang
Thank you for your explanation. I also followed your explanation, but the machine will stop when the positive limit is found during the zero return process, and will not automatically search for the zero switch after the positive limit is found.

Because my zero switch and limit switch are not together, and my requirement is that the axis first finds the positive limit and then reverses to find the zero switch. This entire process should be automatic.

The following is my current configuration
net Zpos_limit lcec.0.2.DIin-16 => joint.2.pos-lim-sw-in
net Zhome lcec.0.2.Din-17 => joint.2.home-sw-in
net Zneg_limit lcec.0.2.DIin-18 => joint.2.neg-lim-sw-in


My Z axis setting is like this

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12 Sep 2021 11:05 #220287 by tommylight
Do not use the HOME switch at all, use the top switch as home+max_limit.

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