Servo Limit Switch Setup

I'm building a milling machine using Mitsubishi MR-J2s servos controlled by LinuxCNC.

These servos have an optional (can be turned off in amp parameters) limit switch input that will lock the motor when the input is taken low.

I know that my Mesa 7i76 can also take limit switch inputs, so the question is: which one to implement? It seems to me like it's a better idea to have the control handling the limit switches, but I want to make sure I'm not accidentally overlooking any benefits to having the servo amp interface with the limits directly.

Can anybody with experience chime in?

Thanks!
Henry

I have just acquired a large milling machine with sizable servos, fitted with a home and 2 limit switches on each axis. I'd be interested to hear what the experts have to say but my understanding is that LinuxCNC doesn't require more than the homing switch and can do the rest in software. That's assuming the software and all its external connections are behaving of course.

My thoughts are to use the end of travel limit switches as "dead stop" inputs to the servos, at a similar (higher functional) level as the e-stop circuit. They should never be required but a single failure could be expensive and / or dangerous.

The original servo system has "directional" limit switches that directly inhibit the servos in the direction of travel only, so that you can jog back out. I believe they are implemented independently of the main controller.

Actually I have a machine with a similar servo drive configuration (using parallel port stepping). I have the limit switches connected to both the drive and to Linuxcnc, and I am homing to one of the limits, and it seems to work just fine (at least for this application). The important factor for it to still work is that the drive only inhibits the motion towards the limit, but still lets it jog off. If the drive errors out and shuts down then it would not work.

That's particularly important if, like mine, there are no handles on the leadscrews.

I hope to retain the directional limit switch operation, independent of the controller.