MHS M226598 in TAM and PI

Discussion in 'Cutters and Trimmers' started by NimeshSilva, Aug 3, 2014.

  1. NimeshSilva

    NimeshSilva Senior Member

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    Hi all,

    Does anybody know about the counter IC of the new version of TAM card or PI card in MONs? MHS226598? (see attached photo). any place to buy or any information is highly appreciated.

    Thanks
     

    Attached Files:

  2. Coloured paper

    Coloured paper Senior Member

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    Hi NimehSilva!

    The IC on the picture was used on boards TAM (second generation) and PI.
    This component is not available in any electronic shop. This IC was specially made for Polar and I do not think this part is broken. Usually the LMS or the LMS trailer cable given you problems.
    What is your actual problem?

    Coloured paper
     
  3. NimeshSilva

    NimeshSilva Senior Member

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    Thank you colored paper for the quick reply.

    It's too bad to hear that this is a custom made IC.

    Actually, the problem with a PI card. The problem is, the machine is not catching the reference. Even the v15 is not lighting up when passing the reference. Please see the attached photo. Can you see a tiny crack on the counter IC? Not entirely sure this ic had burned, but this kind of cracks made for no good. That's the reason why I suspect it.

    But however the "No scale pulses" error is not showing up on the display. That's a kind of relief.
    Anyway, I still couldn't probe the reference signal from the LMS itself.

    Any advice / suggestion is highly appreciated.

    Thank you
     

    Attached Files:

  4. Coloured paper

    Coloured paper Senior Member

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    Hi NimehSilva!

    You are right the IC looks a bit strange. But I think the IC is working correct.

    My experience is, you do not get a reference pulse signal from the linear scale (called LMS). The reference pulse signal is hard to measure. A normal volt meter even including a peak hold function is not enough. The only way to see the signal is using a scope.

    You have the following possibilities for tests.

    First test
    You check the 5V power supply.

    Second test
    If all electronic boards are in the machine, the machine should run without backgauge positioning. The Polar cutters have a special mode in case the measurement system is broken. There are two possibilities to get acces to the secondary operation
    1. If, due to the defective measuring system, no reference point signal can be scanned when looking for the reference point, the machine automatically be switched to “secondary operation” after thre unsuccessful attempts.The screen displays the “program data” image and the text “secondary operation” instead of the actual backgauge position.
    2. When pressing the key “program data” prior to or during the reference point determination the machine is immediately switched over to secondary operation.

    If you are using the “secondary operation” mode you can cut and move the backgauge manually without measurement. IN this mode you can check the whole machine functions (except the backgauge measurement).

    Third test
    Another test is to take the board PI to any equivalent machine. There are two generations of PI boards. One generation has a memory bank for the cutting programs on the PI board. In the other generation the memory for the cutting programs is on the board CP. The difference is easy to see. If you have a little black box plugged into the board PI, the machine is the first generation.
    Before you put the board PI into the equivalent machine you should set the little bcd-switches at the front for the measurement like it is on the other board PI from the equivalent machine.

    Fourth test
    The last test you may do is the reference point simulation. The reference point signal is a very short 5V d.c. signal.
    At the rear side of the mother board you have the plug from trailer cable. The plug number is 23. This is a 9 connector plug type SUB D.
    Pin 1 = 0 Volt
    Pin 2 = Reference point signal
    Pin 3 = counting signal
    Pin 4 = counting signal
    Pin 5 = 5 Volt d. c.
    Pin 6 = shielding
    If you add a push button between pin 5 and pin 2, you may send a reference point signal to the electronic board PI.
    To perform the test, you start the machine and start the normal reference run. The backgauge will move. In the moment the backgauge is the middle of the table you activate the push button for the reference point.
    If the test is negative the backgauge will continue with its movement in the same direction. In this case either your push button does not work or the board PI has a problem.

    If the backgauge is changing the direction the reference point is understood. In this case the board PI is working correct. Unfortunately you cannot give the machine a correct reference point. This would require two or three reference pulse in exactly the same moment (or backgauge position). But at least you see if your board PI is working correct. The next step would be a new trailer cable and a new linear scale (LMS).

    Coloured paper
     
  5. NimeshSilva

    NimeshSilva Senior Member

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    Dear CP,

    Thank you very very much for your long descriptive and informative reply. all these information is really going to help me during the diagnosis. Thanks again :)
    I'll do this and update you about the situation.

    I would like to request one more help from you. I still don't know how to view the inputs and outputs of the machine through the monitor. I've seen that, apart from the LEDs, they can be viewed through the monitor. Can you please tell me how to do this?

    Thank you very much. I really really appreciate your help.
     
  6. Coloured paper

    Coloured paper Senior Member

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    The input /output survey will just show the minimum functions. You will be frustrated. And it does not help in your case.
    To guide you to the input / ouput survey I need the correct machine number and an Email-address. The machine number is necessary to determine the software version of your machine.
    Coloured paper
     
  7. NimeshSilva

    NimeshSilva Senior Member

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    Dear CP

    Thank you very much.
    The machine number is 5831742. the sw version printed on the ROMs of the CP1 card is 4.4.0
    my mail address is nimeshasilva [at] gmail [dot] com.

    Thank you again for the help
     
  8. NimeshSilva

    NimeshSilva Senior Member

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    Dear CP,
    Thank you very much for the information. I appreciate your help a lot.

    But a very very bad news,
    Today I've checked the reference with my PC scope. the LMS is giving the reference pulse in correct timing and voltage. (Please see attached photo) the scope was set to 2V/div and 5ms/div timebase.
    it is confirmed that the PI is not catching it. the reference signal is directly connected to the pin 17 of the M226598 after the RC filter stage. the RC filter is good. so I have no component to suspect other than M226598. :(

    is there anything I can do other than replacing the card? is there any possibility to damage the new card after replacing?

    the memory (RSP), the backgauge brake and all the other functions are normal.

    Thank you again.. :)
     

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  9. Coloured paper

    Coloured paper Senior Member

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    Pin 17 at the gate array is correct. But the input for the board (the incomming signal from the linear scale LMS) is +5V d. c.

    You have a new drawing in your mail box.

    You cannot brake anything if you exchange the board PI.
    But you can try first the jumper at plug 23 from pin 5 and pin 2. Disconnect plug 23 and add a jumper. You may use as well VCC. This is +5V d.c. (comming from the rear side plug of the board pin 3c and 32a) too. Having this high signal, you may compare jumper or reference point signal. Both signals should be enough to activate the gate array.

    Good luck
    Coloured paper
     
  10. NimeshSilva

    NimeshSilva Senior Member

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    Dear CP,
    Thank you so much for the valuable drawing. and I'm sorry for the late reply,
    The scope was showing the signal as 5V correctly (I've purposely lifted the trace one division up for a viewing clarity. So the baseline (0V line) is one division up from the x axis.)

    after studying the drawing you've sent me, yesterday I've powered up the PI card on my workbench (separate from the machine) and applied 5V to the pin 29c. But the V15 didn't light up, and then I connected it to ground for a moment and then back to 5V. again nothing happened. After a while, I got a thought of connecting a pull up resistor. So, I've soldered a 1K pull up resistor to the pin 29c. then I powered up the board again and touched the pin29c with a ground.

    GUESS WHAT...!! As soon as I released it from the ground, the V15 lighted up exactly as it passes the reference. (Approximately. 500mS). Then I've repeated it for several times and every time I touch the ground and release, the V15 lighted up. :) So I hope it means, as you've said, the M226598 gate array is intact.

    But I still cannot figure out where the problem was. I know there is a pull up resistor inside the LMS (connected to the output of the LM239/LM339 comparator) does it got weak or opened? or maybe the risetime of the ref pulse is not just enough to activate the gate array. (because, after carefully studying the drawing you've sent me, I got an understanding of, the circuit is designed in a way that, to ignore the small and slow risetime pulses. Please correct me if I'm wrong).

    What do you think about this situation?
    However, now I have to check it with the machine. I'll keep you updated about the situation.

    and again and again, million thanks for helping me.
     
  11. Coloured paper

    Coloured paper Senior Member

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    Unfortunately I am not good in electronics. But I like working with you.

    Because the signal for the reference point is extremely short the LED V15 has timer. And I really think the gate array is okay.

    In my life this is the moment when I change parts. I would change the linear scale underneath the table first. When you open it, you will see the mechanical stress over the years. The little ball bearings damage more and more the housing. The little spring between the electronic board and the trolley inside the scale is old and will brake sooner or later.
    The next step would be for me the cable. How many movements does the cable made. One million, two million or more?

    You have new Emailss

    Have fun and good luck
    Coloured paper
     
  12. NimeshSilva

    NimeshSilva Senior Member

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    Dear CP,

    Thank you very much for the drawings. I really appreciate your help. And thank you for liking to work with me. :)

    Yes, Now me too think the gate array is OK. But I have to check it with the machine. the client is bit far away from my place. So, I scheduled to visit again in Saturday. (He has another two cutters in his print shop. So it doesn't matter the repair get bit delayed... :) )

    Anyway, I'll update you about the situation.

    Thanks a lot again :)
     
  13. Coloured paper

    Coloured paper Senior Member

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    Take yout time!

    Coloured paper
     
  14. simon yeung

    simon yeung Member

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    Hi NimehSilva,

    Please consider our LMS mod. set if you are looking for the linear measuring system.For details please visit our homepage.It suitable for all polar from EMC-I to EMC-MON.

    http://welvin.byethost7.com/lms/

    Simon Yeung
    Welvin Engineering Limited
     
  15. Coloured paper

    Coloured paper Senior Member

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    Hi Simon!

    With which accuracy would be the positioning of the backgauge after the modification with your system.

    Thanks

    Coloured paper
     
  16. simon yeung

    simon yeung Member

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    Hi coloured paper

    Our LMS mod. set will give the same accuracy as the original POLARTECH LMS since it designed for perfectly replacement of Polar linear measuring system. It has been sold for over 300 sets around the world with appreciation from our customers. For details please visit http://welvin.byethost7.com/lms/ or download this pdf file http://welvin.byethost7.com/LMS%20Mod.%20set_eng.pdf .

    Best Regards
    Simon Yeung
     
  17. Coloured paper

    Coloured paper Senior Member

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    Hi Simon!

    If you connect the encoder directly to the spindle (or jackscrew) you have to include the tolerance of the thread. Do you know the tolerance of the spindle in a Polar cutter with linear scale (LMS).

    It is up to 2 mm per meter!

    Let’s say you have a normal spindle. In this case it would be still a wrong positioning of 1 mm per meter. The LMS had per 0.005 mm one counting signal.

    For me 0.005 mm and 1 mm are not the same.

    It looks like you destroy more than you fix.

    Buntpapier
     
  18. NimeshSilva

    NimeshSilva Senior Member

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    Dear CP

    good news... problem solved.. Now the PI is catching the reference.
    Yes, You were absolutely correct. The problem was with the LMS. As I've studied the PI card diagram you've sent me, the reference portion of the circuit was designed to ignore the pulses below a certain width. the problem was the value of the some of the resistors of the LMS have gone beyond their tolerances and somehow shorten the reference pulse width. after replacing them the problem was solved.

    Thank you very much the support you've given me. and also the invaluable diagrams and information. without you it won't be easy for me to catch the fault. :)

    can you remember the crack in the gate array IC? I think it is a manufacturing defect. most probably a defect in the mold.

    anyway, Thanks again and please keep the good work up. You're a sun to the planets wandering out there.. I have no words to express my gratitude..

    danken Ihnen sehr viel Herr CP
     
  19. Coloured paper

    Coloured paper Senior Member

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    Hi NimehSilva

    I am happy the machine works. Even with the correct information's you need to be able to understand. You did a good job.

    I hope you can fix often Polar cutters. Good luck

    Coloured paper
     

  20. Adrian C

    Adrian C New Member

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    Dear Mr Silva,
    Can you share with us exactly wich resistors you exchanged in the LMS ?
    I seem to have a similar problem because my original LMS is not getting the refference point anymore.
    Indeed, it still counting the pulses, but no refference point . Also the Polar 137 Emc Monitor is working flawlessly with another LMS head.
    Any advice or previous experience is appreciated.

    Thank you .