Centroid Community CNC Support Forum

How can I use wizard to set up my external Cycle Start and Feed Hold button on my lathe, with out over writing my custom machining plcs

I dont believe you can. USB-BOB allows this functionality, dont think you can do it with Acorn on its own.

Select custom PLC in the Wizard, but anyway make a backup first.

IMHO if you do only change inputs in the Wizard, custom changes will not be overwritten.

Uwe

Yes, what Uwe said.

You can wire your buttons to inputs on the Acorn then assign CycleStart2 and FeedHold2 to the corresponding inputs.

So this can be done without the USB BOB?

Chaz wrote: ↑Thu Jul 17, 2025 11:17 am So this can be done without the USB BOB?

Yes, I have several hardwired buttons and switches on my routers wired to Acorn inputs. You do not need to do any custom programming to make cycle start or feed hold buttons work.

You will wire two buttons to two of the Acorn inputs. Assign CycleStart2 and FeedHold2 to those inputs. Be sure and go into the "Alt-I" screen and invert those inputs to make them work.

Correct. The USBBOB is not required for this. It would keep the Acorn's PLC inputs free for limit switches or other things though.

Ah, wasnt aware of this, thanks.

Of course, if your objective is to add CycleStart2 and FeedHold2 input assignments, and then have them work, you have to let the Wizard change your PLC program.

I was working with Janl last month on this last month.

The problems he had with the Wizard were not due to overwriting the PLC program. Instead, they were due to the Wizard overwriting his custom tool-change macro (cnctch.mac) and custom homing macro (cnct.hom).

He should be okay to use the Wizard, as long as he can check the right boxes to prevent its overwriting his tool-change macro and homing macro.

In the last report he sent me, he did have: ... but for some reason the buttons were not working for him.

The only thing "custom" in the PLC program, is code to prevent axis #3 (the turret indexing motor) from jogging any farther in the minus direction after the turret-locked-down switch is tripped. Since that code is in the "acorn_lathe_plc.src" source file, and not in any of the Wizard-generated sections, it should not be lost even if the Wizard is allowed to overwrite the PLC program.

cncsnw wrote: ↑Thu Jul 17, 2025 2:00 pm He should be okay to use the Wizard, as long as he can check the right boxes to prevent its overwriting his tool-change macro and homing macro.

Yup, maybe he also wasn't aware of the boxes to check in the wizard to NOT overwrite certain files.