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Fanuc 0M 2023 2024 error troubleshooting

Fal Grunt

Titanium
Joined
Aug 5, 2010
Location
Medina OH
Was getting 2023 and 2024 alarms intermittently and they have now gotten to the point where I practically cannot run the machine.

I have only gotten 2024 a couple times:
IMG_4928.jpg

I get 2023 on a regular basis. I frequently cannot get a tool to change unless I unscrew the prox sensors clear the error and then screw the prox's cables back in. Typically when I get this error, both prox's are made, and I can only get the machine to index if I unscrew both. I took a picture of the prox switches, but the board doesn't like it!
IMG_4669.jpg

The machine is a Bridgeport Interact 720F. It has a 20 tool carousel changer, which is pneumatic driven over and up/down.

Anyone have any advise on tracking this down and diagnosing what the issue is?
 
You need the ladder diagram to figure out the appropriate input that the machine is not getting. Without that you are just guessing at what the problem might be.
 
Prox switches are not very expensive, I have replaced one in my lathe turret twice and keep a spare on hand. They are fussy as to the position- it's a pretty narrow range and they need the correct gap between the cam lobe and the sensor. When I replace the one in my lathe, I take the bracket and sensor together over to the the inspection plate and use the height gage to set the new one.

Carousel tool changers are down in the machining envelope and a bitch to keep clean. I think I'd swap out the prox switch and see if it fixes the problem.

Or just clean the shit out of everything- that might be enough to get it working reliably.
 
I'll see if I can get the ladder pulled up tonight and get some pictures and an idea of what it's doing.

Funny story on the Prox sensors. I had a friend I used to build machinery with come down and go over the tool changer. We tried to take it apart, but it wouldn't. We pulled the sensors and several of the tool pockets and I spent 5-6 hrs cleaning chip and crap out. The sensors were covered and oil and chips, the cam and internals were packed with crap and dried oil. Cleaned everything thoroughly.

Works worse!!!
 
Pulling up the ladder on the control is a good start, but there should be some kind of documentation on what inputs do what. Otherwise it's just random labels and numbers.

But, if it's like most MTBs, they were way too lazy to give you that info.
 
I spend about 30 minutes trying to find the ladder on the control, after googling a bit, apparently there were 3 iterations of "O" control. Is it an O or an 0? I've seen both? Anyway, apparently, there are 3 iterations of the control, and the first two you cannot see the ladder diagram without loading it off the control into a DOS type ladder program?

Any advise or input on this?

IMG_5401.jpg

HA! Twelfth time's the charm!

Looking back through my box o stuff I guess I did not find what I was expecting for a ladder diagram, at first I really thought I had found it, but looking again, that is electrical? The only other fanuc machine I have run was a newer Doosan, but I forget the control. Lets just say I did not find anything like the ladder on that machine. The ladder on that machine looked just like this one pictured here:
http://www.practicalmachinist.com/vb/cnc-machining/ladder-logic-not-being-logical-304612/
 
That pic of the wiring diagram shows the Diagnostic addresses to check the status of your limit switches and prox sensors. As you actuate them you should see them change from 0 to 1. If they don't change you have a bad switch or sensor or a broken wire/bad connection.
 
Just to add too what VanC said above. The diagnostic bits are the X addresses, on the right hand side of the schematic.

For instance. magazine forward, is limit switch LS10, Its diagnostic bit X (Input) 17.0 Its the zero bit on the right hand side of diagnostic line #17.

Given your alarm, (which is MTB written). I'd start by checking "Mag Ref" Its prox switch #1. Diag X17.2 Surely there's a flag on one pot, that defines it as the home or #1 pot. Don't be fooled if the flag isn't on the #1 Pot, it can be on any pot, but the switch is located, so the #1 pot is at the correct position.

They are pretty good drawings, it gives you wire colours, pin assignments through plugs, wire numbers. I'd count myself lucky to find an Electrical drawing so good..

You will have a faulty switch, its just a matter of physically making them and watching the diagnostics.

Regards Phil.

(ON Edit)
Looking back through my box o stuff I guess I did not find what I was expecting for a ladder diagram, at first I really thought I had found it, but looking again, that is electrical?
What you have there is the electrical wiring diagram / schematic. Not the ladder logic.

If your lucky, you get a hard print of the ladder, even if you cant pull it up dynamically on the control. What you have will do fine. I only count 6 inputs for the entire tool changer functions. Its a matter of checking all of those. X17.0, 17.1,17.2, 17.3, 00.0 & 00.1 One of them isn't in the correct state, hence causing the alarm. I'd start with the Reference one X 17.2, given the alarm message.
 
Ok, I spent about an hour on this and will need some more detailed instructions. Took me 20 minutes to get the ladder pulled up on the machine, which was a complete accident. I tried the P0060 parameter bit 2, which didn't change much of anything that I could find. Randomly when paging through the Diag/Param screens the ladder popped up. After I had already turned OFF bit 2. Couldn't get it to come up before I changed the bit 2 parameter to on, couldn't get it to come up when I turned it on, but magically it appeared after I turned it off again.

On the parameter page, under X17, I checked 1&2 prox switches, both "make" correctly, when unplugged they change from a 1 to a zero, the same when running. When stuck w/ 2023 they are both made and light up both in the control and at the sensor IF the machine sticks at Tool 1. If it doesn't stick on tool 1 I can hit the alarm reset button and and typically the machine will finish the tool change, or get stuck on tool 1.

I took a bunch of pictures and a couple videos I will try to get posted when I get in the house.

I APPRECIATE all the help SO FAR!!

Edited to Add:
Upon reviewing the pictures I took, I am not sure how much help they will be in diagnosing the issue. I did take several videos of the ladder at various points where 17.2 and 17.3 show up. I have no way of posting the videos. Am happy to email them if anyone wants to take the time to see them.
IMG_5408.jpgIMG_5409.jpg

The following are the 3 examples I was able to produce in the given conditions, and the readings of X17 while running a program.
Mag Not A Pocket - stuck on a misc pocket
00101001
Was able to press error cancel and the magazine continue on its way, and load the correct tool and continue the program.

Mag Not A Pocket - stuck on Tool 1
00101101
This is basically "un-recoverable" I have to disconnect both 17.2 and 17.3, press error cancel, the carousel will start to rotate and error out again. Typically then grabbing the next numbered tool from what was called. (T3 called, pulls T4)

When running, carousel retracted, and up:
00101010

One inconsistency about X17.3 that I noticed, at different points in the ladder, you could see them light up together, sometimes, one after another. I got a decent video of this happening. I don't know if this is just the lag of the control or what.

Just for clarification, 17.2 is made with a block when T1 is at the spindle. 17.3 is off the cam plate to index the carousel.
 
Last edited:
Anyone have additional input?

Hello Fal Grunt,
Does your machine have a Tool Change Macro that does more than just ensure that the Axes are in a favorable position for a Tool Change? A Tool Change process can either be carried out completely by the PLC, or by an interaction between a Tool Change Macro and the PLC. Have a look for this (in the 9000 Series Program Numbers), as it may point you in the direction of fault if the Macro is waiting for a particular event to occur.

When testing whether a proximity switch is working or not, unplugging it to change the status of the diagnostic bit doesn't necessarily prove it. If the prox is not switching and it happens to be on, unplugging it will change the state of the diagnostic bit, but doesn't show whether the switch is actually switching. A better method is have the switch in a state where its status can be changed and then manually operate the switch. When playing with inputs to a PLC, initially its better to activate the Emergency Stop so that an unexpected movement is not initiated by the change of state of the input. With the Emergency Stop activated, the status of the input is still able to be viewed.

Regards,

Bill
 
I will have to check what exactly the macro does, but yes it does have a macro.

So, when watching the machine do a tool change, and the bits change, that does not necessarily identify that the prox switches are being made? Prox switches are cheap enough, should I just order replacements and eliminate that variable all together?
 
I will have to check what exactly the macro does, but yes it does have a macro.

So, when watching the machine do a tool change, and the bits change, that does not necessarily identify that the prox switches are being made? Prox switches are cheap enough, should I just order replacements and eliminate that variable all together?

Fal Grunt,
No, that would indicate that the prox is switching; my comment was in reference to testing by unplugging the switch.

Regards,

Bill
 
Bill,

Thanks for all your help in this!

As a perfect display of my ignorance with Fanuc and older and newer(?) machines, I can't access the tool change 9001 macro. I enabled PWE thinking that might give me access. Is there a parameter that needs changed so I can see the macro?
 
No go, I changed those parameters and cannot get the O9001 program to open.

Will post pics of the parameters when I get in the house. Can't load pictures from my phone to the forum?
 








 
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