Setting up Probe Basic on my machine questions and issues

the methodology of using a measured cutter verse probing the tool setter pad with the probe is to avoid probing a moving object which can cause a misread of the actual touch probes trigger height. because no two probes will have the same exact spring rate to trigger the chance of inconsistency or a false touch probe tool length offset is much higher then if probing a solid object. granted this variance would be very small so depending on what kind of machine results tolerance you are hoping to achieve it may be within your use case.

the XOR component would allow for using the touch probe to touch off on the tool setter, it is simply using the component to gate the two discrete probe trigger signals into linuxcnc's single probe input. there are some considerations. if the touch probe is NC and is not mounted connected to the machine full time, ie.. it is plugged in or removed depending on if it is being used or not. this causes a bit of strife as the open signal when it is removed puts the probe input in a triggered state. so if this is the scenario you are using you will need to use a dummy plug to simulate the probes closed circuit at the jack. I have seen some jacks that have the ability to close upon removal of the male plug, they are used for power/charging jacks to divert the power circuit back to the battery when the plug is removed. I think I added a diagram some time ago for this in a post but when/where escapes me.

if the tool setter and touch probe both use a normally closed circuit the single input can be run in series so long as if one is removed the circuit is closed artificially.

XOR can also be used in that scenario, just depends on how you want to configure the system. there should be a stock component specifically for probing to make it easy or a prewritten hal example somewhere in the docs as this question comes up far too often not too.. if you guys come up with a working hal example or examples, we can sticky it here for PB users or other general searches to help folks get it sorted out easily.

Thanks
Haven't gotten back to the touch probe stuff but hope to soon.

Currently a couple other issues. The first is definitely PB related.
Every time I start PB it puts the coordinate readout in inches when linear units is set to mm in the ini.
G21 does switch it but it's still annoying. How do I set it so everything starts and always stays in mm?


The second I don't remember if this was an issue in other UIs but if I hit home x or y it does not lift Z before homing.
I see there is a go to home file in subroutines which I assume is used for home all but don't see anything specifically for individual axis. Would I need to create a subroutine for x and for y to get it to Z0 before homing them?

Your ini start up line has ag20 in it, change to g21.

Homing sequence is set in the ini, read the lcnc docs for how to configure homing settings correctly. All homing is stock linuxcnc motion. Go to home is for the go to home button. You can edit it to suit your needs, but has nothing to do with homing. All homing settings are in the ini under each of the axis sections.