Servo to AXBB-E Limit Switch wiring...

[Phil Mayor]

Hello again, I’ve managed to get the Servo’s to turn the Motors through my AXBB-E Controller just in bench tests at the moment and at a slow speed, I took a while but with a bit of help, I got there… So now on to my next problem, Limit/Proximity switches and E-Stop connecting…?

I have done this before a couple of times but without Servo’s, and with Servo’s I’m not grasping how it connects to the AXBB-E in relation to the Limit switches/e-stop or if it even needs to, maybe I’m overthinking, but if the AXBB-E has the ports for the Limit Switches (port 2) what do the DI Limit connections of my servo do and where do the go? – if I wire my AXBB-E up with Limit Switches, they trip when I hit a Limit which in turn puts UCCNC into reset mode stopping the servos from moving, so why do the servos have Limits, or are these like soft limits, maybe? I'm pretty sure my AXBB-E has the option for soft limits also... just a bit confused...

[m_c]

The servo drive limit input is for if you need the limit switch connected to the servo, which for CNC applications I can't think of any reason that you would.
It's more for if you're using the servo in some kind of standalone application.

[Phil Mayor]

Thanks, m_c. That helps a lot, so I guess I was overthinking this. I'll wire the Limits/ E-Stop as I did before through the AXBB-E Controller. Would this also be the same for the DOs? Do I not really need these in my application?

[m_c]

I've only ever used the Servo Ready, and Fault DOs, however the only one you probably really need is the Fault output (or possibly just the Ready output, as if you lose that signal, the drive has either lost power or faulted), wired in just like you would a stepper drive.

What you use really depends on how much functionality you want in the controller.
You could wire/program servos so you can reset them in software should a fault occur (not all faults can be reset without a power cycle), you can monitor individual drives for faults, you can monitor that each drive is ready, you can trigger a fast/emergency stop in the servo.
However what you implement really depends on the controller (with an AXBB, you have limited inputs, so you probably only want to monitor the essentials), and the size/complexity of the machine.

[Phil Mayor]

Ok that's great, thanks again. I don't think I will use any DI's or DO's at the moment, just to keep it simple. after I've wired the Limits, Probe(s) and E-Stops I will only have one spare DI Port on the AXBB-E so if I understand correctly I could, in the future, wire the 'Fault Output' DO from the Drive over to the spare DI Port somehow, is that right..?