Hi! My colleagues and I are working with a blackbox 32 and would like to add an inductive sensor as Z-Probe. We currently have one with the part no. lj12a3-4-z/by, which is not working. The Machine just runs into it's Z-limit when we try to probe. Yes, the probe touches the metal we try to detect before the Z-limit. It's not fully fixed, so it just slides in a bit while the machine is pushing past the point it should have detected the surface. The label suggests it's a PNP normally open switch working at voltages from 6-36 V. The limit switches are running on 24 V. They're also inductive PNP and we have reconditioned them into NPN for the blackbox to operate with them properly. Do we need to do the same with the Z-probe? Am I overlooking another reason why the probe input might not work with this type of sensor?
And as per section 3.4.3 of the BlackBox X32 documentation: docs:blackbox-x32:connect-npn-inductive [OpenBuilds Documentation] should be NPN NPN sensors closes SIG to GND, which is the type of event the BlackBox needs. SIG is already pulled up, so adding voltage from a PNP does nothing (both states are HIGH). It needs to go LOW (SIG to GND) to trigger (so that untriggered state is HIGH per onboard pullups, and goes LOW when the switch/sensor closes)
OK. Then that's probably the problem. Just to explain my confusion: since the section of the doc on connecting the probe doesn't talk about inductive sensors, it doesn't mention that the probe input also only works with NPN (the part you linked is in the limit switches section if I'm not mistaken). But it makes sense that if that's how the limit switches work, the probe inputs will behave in the same way. So, thank you for clarifying. We'll see if we can make it work by conditioning or buying an NPN version, since those sensors are relatively inexpensive anyway.
Yes, using an Inductive as a Probe is not documented (they tend to have too much drift to really be usable as probe in the first place) but the inputs all behave the same
