[allenp]

Hello, I've got a problem with this older year 2002. Haas VF2 machine, I get alarm 628 ATC arm positioning error...


After checking diagnostic bits, I've noticed that bit Motor Stop goes from 1 to 0 to 1 and back to 0 rapidly (in less than a second) while doing tool change, while it should stay at 1, not switch back to 0...
That should be a problem either with sensor which senses when the tool arm is in position to hold spindle tool and pocket tool, or with the mechanism (cam, motor...) which moves the tool arm and it goes past the position it is normally required to stop before next sequence of tool change.
I think there is more chance that there is mechanical problem than with the sensor, but I'd like to confirm it.


Is there a way I could do manual tool change, or to be more exact to make the arm move manually, step by step, while I'm on the diagnostic screen?


This can normally be achieved while in Tool changer restore mode (then I can move arm manually step by step), but then I can't look at diagnostic screen.
I can choose either being in tool changer restore mode and move arm manually or to be in diagnostic screen and watch bits change, not both at the same time, because when I get in tool changer restore mode and switch to diagnostic screen and press atc fwd or atc rev it says Wrong mode (I did go through MDI)....


?Thanks for any advice in advance.

[saltfever]

You can slow the arm by turning on rapids to 5%. I don't think you can single-step though. I'm at a much lower technical level than you. That's about all I can offer.

[allenp]

Thanks for the answer, but thats not what Ive meant.

Anyways problem is solved, it turned out to be a wrong DC Bus voltage causing motor to overshoot motor stop position.

I had to switch voltage lines on the transformer in control cabinet from lower to higher range voltage. DC bus voltage should be around 330V, you can check on diagnostic screen.

Secondly, I had to switch between Tool changer restore screen, where I've moved the ATC arm to motor stop position and diagnostic screen to see when will Motor stop bit turn from 0 to 1 and back to tool changer restore screen,until in position.
And it did, it stayed at 1 confirming sensor was ok and problem laid somewhere else...

[saltfever]

Thanks, allenp for posting the solution to the problem.