Alarm troublshooting via Ladder diagram

[stevo1]

Ok Ladder gurus, I need a hand on tracking this alarm down.

Vertical lathe with a Fanuc 15tf model “A” PMC.

I have a pallet rinse that runs with an M50 call. When I run the M50 it alarms out with EX31 X-Z AXIS BAD POSITION. Now I do know it has to do with the proper position that the machine needs to be in on each axis. I had this problem before on the other machine and just kept changing my XZ until it finally took. I now want to figure out what it exactly needs to be.

Attached is the alarm, and part of the ladder it alarms out in circled. If I check diagnostic A003.7 it is high “1”. What I do not know is where to go from here. What am I looking for? Documentation is decent so I should be able to find anything you tell me to look for.

I always wanted to get my feet a bit more wet when it comes to tracking alarms and troubleshooting using the diagnostics and ladder. I suppose now is the time to do so.

Thanks guys,
Stevo

[cnc2149]

Your ladder exerpt has an occurrence of a N.O. contact A3.7. You are going to have to look for the coil labeled as A3.7. It is at network 230 which is on the very next page as you have the listing through 229. They'll have some conditions in the ladder that will set the A3.7 coil, which posts the message. Unfortunately, they did not use Symbols in the ladder, so you'll be chasing addresses. Not difficult but it's not uncommon to have to go a level or 2 deeper when you find the coil. You may find Rxxx.x addresses involved in the network, as well. These are internal coils defined by the MTB. I can comment more specifically if you post the next page of the ladder listing.

[stevo1]

Thanks for the response.

I edited the attachment in my first post. I added the next page of ***MESSAGE DATA*** along with the next 2 pages of the ladder.

Stevo

[cnc2149]

In N0230, the logic indicates that when the M50 is active you must have a logic 1 on both X0.0 and X0.1 (since they are both Normally Closed contacts). Otherwise, there is a path to pick up the A3.7 message coil. Looks like X100.0 is a seal in contact to maintain the message.

I'd look at the definition of X0.0 and X0.1 hardware inputs and also observe them on the PMCLAD page to see which one(s) are allowing power flow. Once you find what they are, you'll you'll probably find a problem with a switch input/wiring on the machine side.

[MysticMonkey]

You need to find out which of these items is switching when the alarm occurs

R22.3 = M50

so
X0.1 (NC)
or
X0.0 (NC)

must not be or become 0 while M50 is active

X100.0 would be a switch to cancel the alarm latch, probably a button on the control panel.

find out what X0.0 and X0.1 are from your electrical manual and work out which one is causing the fault