[DEBERRY88]

G'day Everyone

I require some assistance with a Fagor 800TI on a used lathe I bought about a year ago. We have finally fired it up today but it brings up an error code PLC<26 every time the start button is pressed. Could anyone please advise how to deal with this? The machine was in working order when removed from previous owner.
Thanks
David

[TAProwler]

DEBERRY,
You can find the manuals for your controller here:

:: FAGOR AUTOMATION ::

Scroll down to the 800M&T section.

Also, check out the PLC and PLCI .pdf files in the 8025 section above - there is a lot of info in there about the 800T PLC.

Hope it helps.
R/Todd

[DEBERRY88]

Hi Todd

Thanks for your reply and suggestions.
I do already have the original manuals that came with the machine and the "General parameter table" printout as used to commission the machine.
The manual says
026 This error is issued in the following cases
> memory overflow
> not enough free tape or cnc memory to store the part program

Not being familiar with Fagor, despite extensive reading through all the manuals I have not been able to find anything relating to this error or how to rectify it.
I don't understand how either of the above error messages apply when all I have done is attempt to turn the machine on.
Any help or suggestions greatly appreciated

Cheers
David

[TAProwler]

Hey Mate,

I took a look at that too, and those error codes are errors that get returned when you run a part program and relate to the actual program code (G codes, M codes, etc. and their use or syntax, etc.)

In your original post the error was a PLC<26 error. I think that the PLC error codes are a different set of error codes. The PLC is a different beast altogether. I'm learning a F8025M, and mine does not have a PLC - so I'm not too smart in that area yet.

But, I don't mind learning some, becasue I also have a 3 axis mill with a F8040M controller that DOES have a PLC - and I haven't done anything with that machine yet except turn it on and jog the axes.

Have a look at this PLCI manual: http://www.fagorautomation.co.kr/pub.../8025/plci.pdf

Look on the .pdf page 131/189 and you will see this under the COMPILE paragraph:

If the program is not correctly edited, the PLC ends the "compiling" function and it shows the corresponding message.

This message will indicate the first error line detected and why it is wrong.
Once the error has been corrected in the editing mode, the program must be
compiled again.

My guess is that the machine is trying to compile the PLC program @ start-up and it hits an error @ line 26 of the PLC program.

I don't know how to do it yet, but try to find out how to "get into" the PLC program and look @ line 26 to find out what it is dealing with. That may give a clue to what is "not happy" (for lack of a better term).

My first thought is that since you are "re-installing" this machine - there is some part of the machine that is not hooked up yet, or maybe not hooked up correctly. The machine might be looking for a signal that is not there or vice-a-versa - or not the correct signal; or whatever.

On my machine it was the E-stop system. I finally found the one little switch that wasn't "happy" and was causing the E-stop to not send the "turn on" signal to the servo control power relay.

Please understand that this is all just my analysis of what I know from your posts and reading the manual a little. I hope I don't send you off on a wild goose chase, but it is what I'd do if it were my situation.

Happy hunting. Stick with it, and you'll figure it out.
R/Todd

[DEBERRY88]

Hi Todd
Thanks for your latest input.
Now that you have pointed it out it makes sense about the error code. I was curious why the machine showed it as Error PLC<26 but the manual showed it as 026 with no PLC prefix.
You have given me somewhere to start and I thank you for that. I will start investigating as you suggested and if you have any other thoughts please feel free, I don't mind goose chases and if nothing else it is all a learning experience!

Cheers
David

[DEBERRY88]

G'day All

I am still trying to solve my error problem.

Due to the position of the power master switch in relation to the screen I didn't realize that the General Test was being performed as it had always disappeared by the time I walked to the screen. So the good news is that it is doing the test and it does pass!! It will then happily sit there indefinitely. When I press the start button on the console which I believe is to engage the drives etc nothing happens for approx 15 seconds and then the error code comes up, Error PLC<26. Once this code comes up the only way clear it is by switching off the power, the clear and reset button will not clear it(it does clear it but then comes straight back).
I have tested all my limit, home, spindle cover switches and all operate correctly.
Following Todds suggestion (thanks Todd!!) about trying to access the PLC program, I have made up a RS232c cable to try and interface the PLC from my PC. Hopefully I will be able to experiment with this in the next couple of days. Unfortunately no PLC program was supplied with the machine but the General Parameters list was.
Another thing I have noticed is that after the general test, either before or after pressing the "start" button I get no response from the keypad. By this I mean it has power to it in that the emergency stop works, the clear and reset work, and pressing any of the buttons produces a "beep" but nothing actually happens. ie pressing the aux will not bring up any menus as per the manual.

If anybody would like to throw in any ideas it would be much appreciated!

Cheers
David

[TAProwler]

Hey David,

I think that the only button on my machine that will do anything after system test "Passed" is the Op Mode button.

Did you try that? That brings up the menu list to choose from for performing a variety of functions.

Hope it's as simple as that. Let us know.
R/Todd

[DEBERRY88]

G'day Todd

Thanks for your input again!

The 800TG-i doesn't have an "OP Mode" button like the 8025. The equivalent function key appears to be the AUX on the 800. Unfortunately it only "beeps" when pressed but doesn't bring up the option menus as suggested by the manuals.
I was able to play with Fagor's WINDNC program today and thanks to a good friend with computer know how it works perfectly. Unfortunately it doesn't help in trying to solve my PLC error as on the 800 series it does not allow monitoring of PLC variables and resources (it will for the 8050 & 8055)

I'll keep you posted

Cheers
David

[TAProwler]

Hey Dave,
Oh, yeah. I forgot you had the 800TI not the 8025T. There is a gent who lives near me that operates an 8025T a lot. I'll PM him and ask him to look this thread over. Maybe he can think of something.
Cheers,
Todd

[DEBERRY88]

G'day Everyone

My latest discovery in trying to get my lathe up and running is that the 3Amp fuse located beside I/O 1 on the Fagor controller has blown.
I replaced the fuse with the correct type and as soon as the master switch was turned on the fuse blew again.
Any suggestions as to what would be causing this fuse to blow would be appreciated

Cheers
David

[TAProwler]

Hi David,
Nice work on your continued troubleshooting. Looking at the OEM manual, on [pdf] page 49 of 224, it says that this fues is:

4- Fuse. 3.15Amp./250V fast fuse (F) to protect the internal I/O circuitry of the CNC.

With the I/O circuitry not powered, the PLC program was not "seeing" something that it needed to "see" to be "happy." So, my educated guess is that this fuse problem is what is causing the PLC error message that you are getting. That's the good news.

The bad news is, troubleshooting the blowing fuse is going to be a little more technical. With a schematic of the I/O circuitry, it might be possible to figure out what is going on, but that will only be able to be obtained thru Fagor. That might be expensive (at best) and maybe impossible (at worst case). They will probably prefer that you send it in for service.

But, before that - it MIGHT be possible to fix this without the expense of having to have the controller serviced or replaced. Look closely at each and every wire that is connected to any of the pins of either I/O-1 or I/O-2. It will be a long and tedious process, but if you trace each and every wire thru the machine, you might find one that MIGHT be causing a short somewhere. That might be shorting an internal power suppy of some kind that is blowing the fuse. I/O-1 pinout is detailed on [pdf] page 58 of 224. I/O-2 pinout is detailed on [pdf] page 63 of 224.

The pictoral view of the pinouts of the 37 pin d-sub can be seen here: http://pinouts.ru/connector/37_pin_D...onnector.shtml

The pinout of the 25 pin d-sub can be seen here: http://pinouts.ru/connector/25_pin_D...onnector.shtml

In particular, I would focus on I/O-1 pins 30, 32, 34 and 36 that provide +/- 10Vdc to the various axes. Then, if all that checks out, start looking at any pin that is used that is related to any +/- Vdc. Chances are one of these is shorting somewhere and shorting the fuse for the associated, internal power supply.

Good luck and happy trouble hunting.
R/Todd

[TAProwler]

I also thought of a couple more things David.

Maybe as a 1st pass troubleshooting method, try unpluging all of the I/O cables from the back of the control unit, then replace the fuse and then turn it on.

You'll likely not get a self test pass, BUT if the fuse still blows, then you pretty much know that the fault is within the controller itself - and will probably need service from a trained technician.

If the fuse DOES NOT blow, then you know that it's something on the machine side of the I/O connectors that is causing the fuse to blow (like a shorted +/-10V power to the spindle for example). You could also plug in one I/O connector at a time and find out which one causes the fuse to blow. That will narrow down the number of wires you'll have to trace by eliminating one connector's worth of wires. Then you could begin tediously tracing wires to find the fault.

To start to trace these out, completely unpower and unplug all of the connectors on the back of the controller. Then use a good Ohm-meter to test each of the +/- Vdc pins (on the plug itself - not the controller) to ground and see what you get.

If 3 of the 4 have some resistance close to the same value (say 2.4 ohms, 3.4 ohms, and 2.8 ohms for example - I have no idea what a real value would be), BUT 1 of the 4 is quite a different value (say .1 ohms) - then follow that wire first in looking for a short or other fault.

DON'T put an ohmeter onto any of the pins on the connectors on the back of the controller. Without knowing what is in there, you could do damage instead of finding damage. Most everything on the "other end" of the I/O cables will be able to withstand the probing with a typical ohm-meter.

This testing might be inconclusive - it depends on where these +/-10Vdc signals go. Mostly what you're looking for is some kind of a short before these wires goes into the servo control cards. But, the servo control cards could be bad too and could be shorting the +/-10Vdc to ground. It's really hard to say.

I'm hoping that by tracing these wires one at a time, you'll find a wire that is bent around a sharp corner and the shielding has frayed and rubbed into a "hot" wire. Or, maybe find one of the connectors has frayed has wires that are shorting somehow. I'm really hoping that it is not a problem that is internal to the controller, because that will be expensive - and maybe cost prohibitive for a controller that is as "well seasoned" as that one.

Good Luck.
R/Todd

[DEBERRY88]

G'day Everyone

Firstly a big thank you to Todd for all your help and suggestions and a PLC expert here in Aus (thanks John) for his knowledge and support.

I started by removing all the plugs from the back of the controller, replaced the fuse and switched on the master switch. The fuse didn't blow.
I then replaced one plug at a time (with machine off) before trying the master switch again. I replaced the plugs in order of RS232,A6,A5,A4,A3,A1 X1 X2 I/O3, I/O1 all without blowing the fuse.
Plug in I/O2 fuse blown!
I then removed the wires number 1-19 from the X-11 distribution board for I/O2. The reason I removed numbers 1-19 is that it is the easiest half to get access to of the distribution board. With these wires removed the fuse didn't blow.
Anyway I managed to isolate the fault to Pin 18 I/O2.
With absolutely everything else connected except Pin 18 I/O2 the fuse wouldn't blow.
What had me puzzled is that Pin 18 on I/O2 is daisey chained to pin 19 I/O2, Pin 18 I/O1 and Pin 19 I/O1.
This had me reasoning that the fault must be in the Fagor, as if the fault was external it should have been a problem on the other three pins as well.
The electrical diagram supplied with the machine indicates that all four mentioned pins should be "0" volt. Testing the four disconnected from the connection block indicated that all were connected to earth with no measurable resistance, and had no voltage through them
With Pin 18 I/O2 still disconnected, I pressed the "start" button and both drives and VFD activated as well as the lubrication pump. I was able to handwheel both axis however the Fagor keyboard was still not operating, but at least it was a start.
I kept working through the wiring and found a non factory lamp had been installed at some point and one wire was going to the "0" volt common wire 0335. I removed this wire, installed Pin 18 I/O2 and turned on the master switch. The fuse DIDN'T BLOW!!!!
Unfortunately I only had time to try a few things, but unlike before I could Jog both axis with the keyboard, pressing the coolant pump button the green light came on the keyboard, the inc/abs keyboard light came on, and the keyboard step/continuous jog button works.
I am not sure why this lamp wire would be affecting only Pin 18 I/O2 and will have to investigate further.
It is also slightly annoying that the Fagor manual for the I/O2 is incorrect. It says it is a 25pin connector when in fact it is a 37 pin and the pin numbers/wiring doesn't match.
Whether all the problems are solved remains to be seen but it does look promising.
The only other thing that is surprising is that the lamp that appears to have caused the problems was working prior to me disconnecting it. The lamp and it's connection will also requires further investigation.

I will keep you updated on my progress as it happens, I am only able to work on the machine on Wed-Friday.

Thank you again to Todd and John for all your help and support
Best regards
David

[TAProwler]

Nice troubleshooting David! Congrats.

Those pins are daisey chained to prevent a "loop" from developing between these common points of "0V" (zero volts). Although those pins (including pin 18) are all labeled 0V, they are not ground.

The signals that are sent to the various servo control boards are floating potential wires (not grounded on purpose) to prevent electrical noise from affecting their operation. That 0V point is the common point for the signals to all your servo control boards. The computer "tells" these servo boards how to move the associated motor by varying a DC voltage signal somewhere between +10Vdc and -10Vdc (including 0Vdc). The 0V reference is what tells the servo motors not to move (but it can't be grounded).

Tell me more about the lamp. What's the other side connected to? I'd suspect it's probably +24Vdc (just guessing). Is it incandesent? LED?

The lamp that you mention was probably (somehow) either:

1. grounding that 0V point in the system and causing the fuse to blow, or;
2. (more likely) trying to tie that 0V point up to some larger voltage through the lamp and causing the fuse to blow. For example; lets say that the lamp is connected to +24Vdc and it has a 6Vdc drop across it when operating. That means that the lamp was trying to make that 0Vdc point actually be at 18Vdc. That was probably giving the internal I/O power supply fits and might be what was causing the fuse blowing problem. I'd have to see the circuit diagram to be sure.

It should be a fairly simmple matter to re-wire the lamp to a more appropriate power source and a real machine ground.

Very nice work. You've got the problem pretty well in hand.
Let us know how it turns out.
R/Todd

[DEBERRY88]

G'day Everyone

Thank you again Todd for your advise.
Regarding the daisey chained inputs, they are definitely grounded. The other end of the pin 18 I/O 2 wire terminates in an electrical block with a number of other wires all 0335, there is a whooping big earth wire from here to earth. This is also shown in the machine wiring diagram.
The lamp is a halogen 24v typical machine type. I changed the power supply to it to the transformer that runs the other lamp and hooked the earth up to a machine ground.
The machine was now powering up nicely. No fuses blowing. All functions appear to work, menus and options all accessible, spindle running nicely.

Everything was perfect. For two days I just endlessly played, powering up, running, testing functions etc all without any problems. By Thursday night I thought all was perfect.

Friday was disaster day!

Turned on the machine and it powered up as normal. Released the emergency button and the fuse blew. This is totally different from the previous problem. Originally the fuse blew as soon as the master switch was turned on. Now it blows when the Fagor panel emergency button is released. Needless to say I am not a happy camper! I spent most of Friday trying to isolate this latest problem but with no luck yet. I guess I know what I am doing come Wednesday!!!

I'll keep you all posted

Cheers
David

[TAProwler]

David,
Glad to hear the good news. Sorry to hear the (a) problem is back.

Since the E-stop system is a 24V system and the lamp was a 24V lamp, the problem appears to be related to the 24V power supply and/or 24V system. Somehow your 24V power supply is interacting with the I/O power system in the controller and they aren't playing well together.

It doesn't seem to me that the 24V system should be blowing a fuse in the controller's I/O system. Without circuit diagrams, I can only speak in big picture terms - but it seems to me that either:

1. The 24V system is somehow trying to go to ground thru that small fuse in the I/O system. Or;
2. The 24V loads (the lamp and the E-stop system being two big ones) are trying to pull all the 24V power (current) thru the I/O system fuse.

Obviously, the fuse is not sized to be able to carry that load (to protect the controller and the I/O system). So, you'll have to look at how and why those two systems interact with each other (and tie together). Then look for how they should be more isolated from one another and are not.

Keep diggin'. You'll find it eventually.
R/Todd

[TAProwler]

Hey David,
Haven't heard from you in a while. Just wondering if you got your system up and running? If so, what was the problem/fix? Thanks.
R/Todd

[DEBERRY88]

Hi Todd

Endless fun and games here.

What I discovered is that somehow the relay control for the emergency stop had 5volts to it even when it should have been 0volts. Then when the 24volts it should have was activated it would blow the fuse.
I never did get to find the exact source of the five volts. While testing different aspects of the wiring and testing for shorts the problem went away. I am hoping what ever I did is a permanent fix.

After this the machine behaved itself for a couple of days.
I might add at this point that I still have not run a job, just slowly jogged the axis, tested the spindle etc.

I started the machine and everything fired up fine. Turned the x axis handwheel and the machine shutdown!!! Went and checked the fuse and it was fine. Pressed the start button again all good, turned the x axis handwheel again, and again the machine shut down.
Z axis worked perfectly and the spindle worked perfectly.

In light of my recent electrical problems I went hunting for yet another electrical fault. I swapped the plugs at the handwheels to eliminate the MPG'S- the fault persisted. I then started tracing the wiring harness from the MPG to the Fagor. Couldn't find a fault.
Finally, after more time than I care to admit, I tried the Fagor keyboard to move the x axis rather than the handwheel, the machine shut down!!!
After disconnecting the wiring from the keyboard and trying the handwheel and then vice verse with the same result I came to the conclusion I was looking in the wrong place.

I removed some covers from the machine and gained access to the servos and belt drives. The z axis I could easily turn by hand, the x axis I couldn't budge. The million dollar question now was is it the motor or the ballscrew?
After removing the timing belt it was evident the problem was in the ballscrew. It was jammed solid. In order to gain access to the screw the whole machine had to be moved as it is located close to a wall, and in order to remove the cross slide the rear of the cabinet has to be removed,the motor,encoder,ballscrew bearing mount etc as the ballscrew/ballnuts and cross slide had to slide out together as one unit towards the splash back.

The funny thing I discovered is that the machine has a PLC controlled self oiler for all slideways and the Z axis, but the X axis is manually greased.
It would appear that the grease had essentially solidified while the machine sat inactive. The limited slow jogging I had done jammed up the ballnuts.
Soaking the screw/nut in Inox loosened it up and I then repeatedly flushed the screw and nuts until everything was spotlessly clean and smooth. The screw/nut is now ready to re install.
What I still cannot understand is why self oil everything else and leave the x axis as a manual grease job!!!

With the x axis removed I decided to flush all the oil lines. I removed the distribution block and all the feeder tubes (10) and flushed them all and the casting until it was all clean and flowing freely. After re assembly I ran the self oiler and was disappointed by the amount of oil flowing on the slides. I was only getting one "splurt" regardless how long the pump would run.
The oiler consists of a pump, valve block and fluid level gauge. I thought the problem would be the valve block so I removed it and dismantled. After careful cleaning and checking all orifices were clear, I replaced the O ring and reassembled. With a little tweaking of the valve needle setting it is now working beautifully with oil flowing for the duration of the motor run.

I am taking the opportunity with so much of the machine dismantled to strip and repaint the bed, toolpost, etc etc
With Xmas and New Year out of the way hopefully progress will be a bit more rapid

Thanks for your interest Todd, I will keep you posted

Cheers
David

[TAProwler]

Thanks for the update David. That is a lot of work and troubleshooting. Hopefully, from here on in it will go smoothly for you.

When you put your X belt back on, if you don't have the motor and the ballscrew lined up exactly as they came apart, you will likely have to change some of the parameters in the CNC.

Connecting the screw and motor together in a "different place" will move the home position and the soft limits for sure - and maybe another parameter or two that I've forgotten. It's fairly easy to "re-calibrate" and reset the parameters. But, be careful on the initial runs because the X axis may want to move too far in one direction or the other and hit the physical (E-stop) limit before it hits the soft limit.

You may be familiar with this already, but I thought I'd mention it. Holler if you need a point in the right direction when it comes time for that.

Nice troubleshooting and nice work on getting that machine restored.
R/Todd

[DEBERRY88]

Hi Todd

Thanks for the reminder regarding the positioning of the motor and screw.

I must admit I hadn't given it a thought with everything else going on with the machine.
I am hopeful that the painting will be finished within a couple of weeks and then I can re assemble the X axis on the machine.
I will have a closer look at the manual during the evenings and try to nut out the setup procedure. If I have any problems you will be the first to know!!!

Thanks again for sharing your knowledge
Cheers
David