[dpellarin]

Hi,

I have a 2000 Fadal 4020 with the standard Fadal MP CNC legacy control that has been acting up lately. The control is running a lot slower than usual when switching from different modes. For example going from Manual to Auto the screen goes blank for several seconds and then partially loads and after a few more seconds finishes loading. The slow processing is also evident in a tapping cycle. The spindle comes down getting ready to tap and then just stops for several seconds, taps the hole, retracts and sits again for several seconds before moving to the next hole. Just wondering if anyone has any ideas on what might be causing this. I have another 4020 that I could swap parts with to troubleshoot if necessary.

Thanks,
Domenic

[Rally]

How are you handling the Heat! Every summer our shop goes to the sane thing witch in our case shows up in the repeatability.
Do you shut down the Machine at night or let them set with the E stop depressed?
I'm sure you have probably already tried to reboot, but did that seem to do anything.
Have you recently done some updates?
At what percentage are you with the machines memory?
These are all factors that need to be considered. Not trying to be a smarta.. but can you trace the problem back to the day it started and recall what you did that day.

[yanjue]

It can be the memory or cpu, if Rally can't help you.

Yan

[dpellarin]

It has been an ongoing problem prior to the heat. It gets shut off every night and the next morning when cold its still doing it so I don't think it is heat related. I have tried zeroing the memory and this did not make any difference. No changes or updates have been done to the machine either.

Thanks,
Domenic

[Rally]

Well, judging by all the Info. provided by you I would almost second the CPU or Memory. However, I really cant make that Call. I would try contacting your nearest repair facility and ask them it that has been a problem. In all honesty a CPU or memory failure would be or at least had to have been a heat problem in the past. Is your shops power filtered? Could it have been a Voltage spike??
Sorry! I'm out of Ideas after that.

[dpellarin]

Thanks for the ideas. When I get some time I will swap out the CPU and memory with our other machine and see if this solves the problem.

Domenic

[denmars]

If it has a memory expantion board,,,Remove it..

[dpellarin]

Yes, it does have a memory expansion board. I removed it today and it didn't make any difference, so I guess it is probably the cpu board causing the problem.

[Jody20]

I have seen several things that may cause what you are experiancing. The most common is a loose fitting memory expansion board. The machine will run with the board loose but you will experiance the problems that you are now. Another thing is when the memory becomes corrupted by the loose board. You have to reseat the board and use the RI comand in Command Mode. THis clears the memory and any corrupted data. THe reseating of the board corrects the problem short term. If you do a lot of very heavy machining the board will probably shake loose again. Some times you have to reseat the board that Memory Expansion Board sets on. When I'm in there I reseat all boards at the same time. It eliminates a lot of problems at the same time. Hope this helps.

[neilw20]

I have seen this problem on various makes of machines, and in most cases it can be traced back to loose/bad/intermittent connections.
Rubbed through shields, or intermittent breaks in shields to encoders can also create these problems.

Simple Explanation:
Many parts of the IO processing of a CNC machine are interrupt driven.
Normally the quantity of interrupts do not take up all the CPU time. There is still some left for normal processing of interrupts, switch scans, movement,IO queue processing, G-Code processing, display update probably in approximately that order of priority.
If any of the higher order priority tasks use up all the CPU time, then the G-Code processing (which feeds queue processing) and display updates suffer and show as a symptom.

A dirty or intermittent manual feed or speed over-ride potentiometer can also create extra interrupts by the output varying, like a noisy volume pot on your stereo. Try the pots in some other position to where they normally operate. Maybe just some contact cleaner is required. Only clean if it evident that this is producing a problem.
otherwise...
Almost certainly something(s) are making intermittent connection.
Blame external wiring first, then internal connectors, then PC card connectors followed by IC sockets.
Also look for conductive dust like contaminants around PC cards and connectors. Blow it out carefully with dry air with air blast a reasonable distance from components. CAREFUL: A good air blast can REMOVE components.


Watching this space....

[dpellarin]

Ok, so after checking for loose connections and re-seating boards the problem still persisted. I had our local fadal repair guy come out today to observe the problem. He noticed right away on the jog screen that the following error on the y-axis was 16 while the machine was stopped. He adjusted the balance on the y-axis amplifier and got the following error down to 0 and the control started running normal again. So this adjustment seems to have fixed it. Thanks for the help on this.

Domenic