Hi All -
Got a couple of questions, and rather than bother CNCRoom / vrasak privately, I thought I'd post here and make the answer public knowledge!
First up - I've got a few LED switches used to control various things. One of the switches is the Limit override button which I've used a UB1 output to light up only when the hard limits are triggered - I've followed the manual religiously, the diagrams always use a +24V pin from the UB1, load, then Y3XX input pin to 0V. I'm now at the stage of pulling this button out to a remote control panel - It would be significantly easier if I could use a +24V line not from the UB1 - is that an issue? The +24V line is from the same +24V PSU that powers the UB1 (and common electronics sense tells me it should work absolutely fine) but I just wanted to check.
Second - using these outputs to power external relays (see link below). Can I just connect them without risk of back EMF damaging the UB1 or do I need to use some type of protection (e.g. reverse bias diode?) - I'd plan to go from +24V to A1, A2 to UB1 Y3XX.
https://uk.rs-online.com/web/p/non-l...elays/7943771/
Third - Probing via grounding method. I'm new to the probing game - never set one up before, so forgive me if I'm being ignorant. Essentially I think its just a switch circuit running between X1XX to a touch plate on the bed, then connecting a 0V crocodile clip to the bit. The circuit is made when the bit touches the touch plate - please correct me if I'm wrong. The problem here is that my spindle is grounded, as is the frame of the CNC - Doesn't that mean I'll be grounding the 0V of the PSU? I thought that was a bad thing... Is there something I'm missing?
Fourth Question, while I've got your attention, is grounding in general (not UB1 related at all). I'm using a stainless steel gland plate, so all the screens of my CY cables out of the electronics cabinet are common here just by screwing the socket in. I'm also using some shielded CY cable inside the cabinet to take those lines from the gland plate to the drivers. My plan is to only ground each CY cable at one end, which may as well be this gland plate, and then run that back to the incoming earth. Does that sound reasonable?
Thanks!