homing error 457 and 407

[Houseman303]

Homing has been working without any problems for about a month. Today I made some parameters in the configuration. P3, P4,P11,P39,P257. Now I have error 457 Unable to find home. P180 =10. I haven't changed anything mechanically, and I haven't had a crash either. P180=0 moves exactly as far away as with 10. P180=1 gives error 407 Z+Limit tripped.

[Houseman303]

Apparently P11 gives a minus value for nc sensor seems to be the problem for homing. But P180 also seems to have a problem with the distance, i.e. not driving the distance that you specify.

[cnckeith]

hello. what are you trying to accomplish?
need to know the goal to help out.

[Houseman303]

P11 sign change means that the machine can no longer reference. The P180 is not working properly. Surely I should report bugs?

[cncsnw]

This may be similar to an issue I reported 9/27/23 while working with K104703: if the probe input indicated in Parameter 11 is showing a tripped condition (e.g. positive P11 and closed input, or negative P11 and open input) then CNC12 reports "457 Unable to find home" when you try to home the machine, instead of a more informative message such as "916 Unexpected probe contact".

Houseman303: when you set P11 to a negative value, did you also connect your normally-closed probe to INP769, and leave it connected?

If you set P11 = -50769, and P18 = 0, and then remove the probe, the control must assume that the probe is still in place, and is in a tripped condition. The control is entirely correct in refusing to move the axes (e.g. to home), because doing so might damage the probe. The only shortcoming in the software is its failure to provide a useful error message.

If you want to use a normally-closed probe, and you do not wish to leave it plugged in all the time, then you must provide a probe-detect circuit as well, and set P18 accordingly.

[Houseman303]

It is therefore an error if the axis moves during homing and then outputs an unusable error message. If it recognizes the test contact as triggered, it should not move the axis. P180 doesn't explain to me why an error message appears with one setting and not with others. 4 different values ​​tested, axis always moves the same distance from the sensor.