fanuc 0m cycle start unresponsive please help understanding this ladder

So last week we had a operator wipe out the parameters on an older Kitamura mycenter 3 Fanuc 0m. I posted a thread and VancBiker advised me and I got it back up. I was missing the diagnostic params and Kita OEM provided them for me. This mill has a 4th axis as an ad on so I had to do some tinkering with the params to get it to be seen by the control.

Now everything works in MDI and manual but cycle start does nothing. I see the bits change in Diagnostics when I cycle start so the button seems to work. I took a pic of the Ladder. 1st pic is while cycle start is pressed. 2nd pic is while cycle start is not pressed. Although I thought these would be reversed. Maybe I have is mixed up? I only know a little about ladders but would love to know more. It seems to me that several other contactors need to be closed for the rung to complete and move to next rung. In Fanuc maint. manual F149.5 is named TAP(taping mode maybe?) F149.1 is RST(reset state I assume)How do I track down R577.5?

Thank you very much,

Steve Austin

R577.5 is the latch to hold cycle start in. Hunt down X006.2 that is a physical input. But, are you sure this is the cycle start rung? One would typically think that you would be looking for the X002.6 as a NO instead of a NOT as shown in this rung.

What are the contents of DGN 700 and 701?

No, I am not sure if this is the rung. This is where the ladder displays when I pull it up. I will look harder tomorrow and check the contents of 700 and 701. After you suggested it, I read about these diagnostics. This will tell me much. Forgive my ignorance but what do you mean by "One would typically think that you would be looking for the X002.6 as a NO instead of a NOT as shown in this rung"?

Thnak you

I would think the rung with the actual cycle start would be looking for there to be a normally open contact and would be displayed in the ladder as --||--- what is in your picture has is a binary NOT (line crossing the vertical bars) essentially meaning the contact is not made. I don't think that is the cycle start rung at all.

Tonytn36 said:

I would think the rung with the actual cycle start would be looking for there to be a normally open contact and would be displayed in the ladder as --||--- what is in your picture has is a binary NOT (line crossing the vertical bars) essentially meaning the contact is not made. I don't think that is the cycle start rung at all.

Click to expand...

Typically this ^ is the way Fanuc controls want to see Cycle Start. Feed Hold uses the NC -|/|- logic.

What year is the machine?

We have a '93 mycenter 3 with APC and 0m control. We don't have a 4th added on.

Not sitting with the machine manual in front of me...

You say that MDI and manual modes work, does cycle start in MDI do anything?

If it does, are you sure that the machine is fully homed out in all 4 axis?

Some of our 0m controlled machines won't run programs in auto mode unless it has been fully homed out, our kit included (They will run commands in MDI). I'm sure there's a fanuc parameter for that. This seems simple and you probably have that covered, but lets not dig too far into the ladder without knowing for sure that it was homed out properly. (There may have been one time where I was sure I homed it out but the machine wasn't working, made me pull out the manual and troubleshoot the ladder. Later I re-homed it. Turns out I never homed out z in the first place)