CPU alarm 1-1 bus error

Hi there,

Since yesterday my Okuma LCS-15 no longer starts. All I did was take out the backup floppies from the rear cabinet to help out a guy that contacted me on this forum. How ironic. The screen displays now gives me a CPU alarm 1-1 bus error. See attached pictures. The address is FCC8 and I have read somewhere on this forum that 0xFCCxxxxx is the TFP board. The least significant 2 bytes of the address are random but the 3rd byte is always C8. The 8 is probably the address of a device on the board itself or in an RAM chip but I do not know which one.
I have had instances where the machine will continue but then a VAC drive error (P-938) is cast. Could something like this be caused by a defect in the fibre cable or transceivers? Or would you say that this may be caused by some intermittent bits in an SRAM on the TFP board?
I basically need some way to rule out the TFP board or the fibres before I order replacement parts.

I must say the machine has been off for at least two weeks but it is in a dry, 17°C environment. I re-seated the boards to rule out a bad contact in the back plane. I also checked the supply with a scope but no problems there.

I checked the fibers with a regular LED light to rule out any real break and the light throughput seems to be consistent over all cables. The light coming from the transceivers seems very faint. When you pull out a transmitting fiber, from a reception socket, are you supposed to see an obvious shiny red dot? All I see is an extremely faint light, but only after complete darkness in the room. And even then you have to look closely. Is this normal?

Any help is greatly appreciated.

Attachment 354970

Hi!
I had bus error on my old OKUMA LC30. It was encoder. You can check the cables to motors.

The orange cables are very fragile fiber optic cables and if they get abused in any way, they will fail and give you alarms such as you are seeing. They will not show a red dot, but should transmit light clearly through them since they are glass. If it's not coming through well, they could be fractured. I'd try swapping them out with good cables to see if the problem goes away. A few spares are always good to have on the fiber optic machines. There's a reason they went away from that design to the newer field net design. Your error indicates a communication error, so it's rather likely it's a communication cable.

Thanks a lot for that. I will order some new cables and check it out.

OkumaWiz is correct - those fiber optic cables are really fragile and break very easily. Maybe you bumped one when fetching the disks out of the cabinet, but you are saying that the light looks good through them which is usually (not always) a good sign. We stock those cables, as well as drives, power supplies and control boards (I know we have multiple 2-channel TFP boards in stock, not sure how many 4-channel ones we have). If you end up needing any, you can contact me at [email protected]. BTW, the address does point to the TFP board, but it could mean that is where the communication stopped due to one of the cables that is plugged into it.

Thanks guys,

I really appreciate it. I will keep your data and contact you in case I need components or cables. Luckily there is no real time pressure to get it going but still I prefer a machine in my shop to work ;).

Hi,

I found a problem with one of the transceivers on the TFP board. The machine starts now, but since I did a software re-install before it now shows an error message related to the turret, Alarm-A 1244. I suspect it has something to do with the default parameters that come with the floppies not being correct. Would anyone with an LCS-15 provide me a TOP-file, MSDOS converted? So I can convert it back and make a floppy to restore the parameters in my machine. I was not able to make a parameter backup because the machine failed and I always assumes the parameters would be on one of the 6 floppies that came with the machine.

That alarm is happening because after you load the software it sets the number of stations on the turret to zero - you need to set the parameter to tell it how many stations you have on the turret. I'm going off memory here (check in your book), but I think it is Optional word #47 for the A turret. As for .top file, it probably won't do you much good to use someone else's file, as the stroke limits and zero offsets are going to be different, so you need to re-establish those anyway.

Dear cncts11,

So it was the TFP board itself as I suspected. I replaced it and the machine booted. A client of mine who works with fiber on a regular basis wanted to offer me some multimode fiber cables from coming from stage audio and he claims they will fit the sockets just as well. I may try that eventually. But first I would like to have another go fixing the defective board. I suspect the fiber transceivers or maybe the SRAM of the serializer/deserializer. I do not think it is an okuma asic, at least I hope not. If I get to fix it, I will let you guys know what components I had to replace. The same client that wanted to offer me the cables also told me that there are still pin-compatible transceivers out there. That sounds promising.

That was the correct parameter indeed. After putting the amount of tools for turret A in that parameter, the machine started. After some more research in the pile of books I figured out that there also is a bit table where you need to put the bit pattern of the turret indexing encoder for each individual tool.
There where a few other parameters I needed to change from the standard. I know the stroke end and back lash variables are different for each machine. I experienced this when I took of the belt from the X-axis to solve a mechanical issue with it. But the TOP-file may still be of use to me for the rest of the parameters. That is if the senders' machine has got the same options (tail stock and chip conveyor, no spindle orientation) and modifications. One such modification is the addition of a safety relay on the door lock.

The machine seems to be operational now and seems to be working as before. I learned a lot about it so my time on it is not a complete waste. If I can help anyone out, I will. They guy I sent my floppy backup to never got back to me. I guess he will face the same issues as I did after re-installing. I hope this thread will help him as well.

Thank you all very much.

Hello i have same problem with my okuma lb15, maybe there are still alive someone who can help me? Please contact with me here or by email [email protected]

Resolve the problem?

good morning. a few years ago you had a problem with your machine alarm 1-1 cpu bus error. I would like to know if you solved it and how. access address FC1000FC do you know which card could be causing the problem