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IndustryArena Forum > Machine Controllers Software and Solutions > Centroid CNC Control Products > Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn
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  1. #1
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    Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn

    Finally looking at replacing the Linux based Servo3IO and CPU10 DC servo drive in my Ajax DM45NC mill with something like the Acorn. I looked at other controls but am pretty comfortable with the Centroid software so why learn something new? I'm hoping to get as much pre-wired as I can before cleaning out the cabinet. The power connections for the servos are obvious and I plan on keeping the existing servo power supply. I have three of the 150 volt, 20 amp Machdrive BRC drivers coming to drive the existing servos. I have not ordered the Acorn board yet - still making sure this is the route I want to go. I need to figure out the brake on the Z axis and I'd like to make a panel that the three 9 pin sub d cables simply plug into instead of cutting them off and rewiring them to the DC Servo drivers. Does anyone happen to have the pinout of the 9 pin encoder cables that plug into the bracket connected to the CPU10 board in the PC?

  2. #2
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    Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn

    Ask Centroid support about upgrade options. There are ways to either keep the SERVO3IO or go to ALLIN1DC. Both will be simpler and better than trying to piece together something with ACORN.

  3. #3
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    Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn

    The ALLIN1DC would definitely be a nicer solution. It has the same mounting footprint as the SERVO3IO, and would allow you to use the existing servo power supply, and to use the existing motors and encoders without changing the cables.

    The pin-out for the 9-pin encoder plugs is found on nearly every Centroid DC-servo system schematic. It is:
    pin 1 : n/c
    pin 2 : COM (0VDC)
    pin 3 : /Z
    pin 4 : /A
    pin 5 : /B
    pin 6 : Z
    pin 7 : A
    pin 8 : B
    pin 9 : Vcc (+5VDC)

    With these assignments, encoder channel B leads A in positive rotation, which is CW as viewed from behind the motor (or CCW if looking at the motor shaft).

  4. #4
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    Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn

    Thanks for the information - that will help a lot.

  5. #5
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    Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn

    Quote Originally Posted by cncsnw View Post
    With these assignments, encoder channel B leads A in positive rotation, which is CW as viewed from behind the motor (or CCW if looking at the motor shaft).
    In less technical terms, A and B signals are swapped verses "industry standard". This is a likely point of confusion if you wire to different drives.

  6. #6
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    Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn

    Thanks for pointing that out - I had not looked that closely at it yet. Still gathering information at this point. I did sent a message to Centroid but no reply yet (beyond the one from cncsnw). I've even looked at a couple used DC3IO setups on ebay but have a feeling I'd be buying someone else's problem and not really bettering myself - Intermittent problems are a bear to troubleshoot - just wish I could say I need to replace "A B or C" and be done with it, to be honest. The best I can do is say that it is either the CPU10 or the Servo3IO at this point, or possibly even a software glitch. I can't imagine the motherboard causing the issue (I replaced it once already anyway). I am looking to try a SSD in place of the compact flash, if I can ever figure out how to clone the Linux software over to the SSD and see if it will boot in my motherboard.

  7. #7
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    Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn

    Quote Originally Posted by SEK22Hornet View Post
    Thanks for pointing that out - I had not looked that closely at it yet. Still gathering information at this point. I did sent a message to Centroid but no reply yet (beyond the one from cncsnw). I've even looked at a couple used DC3IO setups on ebay but have a feeling I'd be buying someone else's problem and not really bettering myself - Intermittent problems are a bear to troubleshoot - just wish I could say I need to replace "A B or C" and be done with it, to be honest. The best I can do is say that it is either the CPU10 or the Servo3IO at this point, or possibly even a software glitch. I can't imagine the motherboard causing the issue (I replaced it once already anyway). I am looking to try a SSD in place of the compact flash, if I can ever figure out how to clone the Linux software over to the SSD and see if it will boot in my motherboard.
    I just upgraded a CPU10 to the latest (and last) software revision for it I ordered the SSD from Centroid, preloaded and configured. You just need to send them a report.
    I also upgraded the motherboard to one of their recommended motherboards. I spent about $100 buying it off of ebay with 2gig of memory. Machine is working very well and was the most cost effective solution.
    I agree with Marc (CNCSNW) if you want to upgrade, go with the All in One DC. It would be the easiest path and less downtime. You will retain the true closed loop system.

    I think CPU10 with the latest software revision is a good inexpensive option too. All in about $500 if you order the new SSD from Centroid preconfigured and you track down a motherboard.
    All in one DC is going to set you back $2250, you will need a new PC about another $200-$500 and you don't mention if you have a pendant/console with your current control. All that is going to add up.
    You should post a picture of your machine, and a shot of the control cabinet.

    I will tell you the biggest issue I had was USB compatibility. Once I upgraded the software, all that got much better.
    Pictures of the mill and the M400 control: https://photos.app.goo.gl/JYQVB3aBjC7xWX3Y8

    Marty

  8. #8
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    Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn

    I upgraded the motherboard and went to the latest software revision a couple years ago. Only difference is that I kept the Compact Flash card. I did manage to clone the compact flash card to a Samsung 16 GB SSD that I had and tried it last weekend - didn't have time to run any parts but it booted up fine and went through homing fine. I dry ran a couple small programs and they ran fine, so I'm no worse off than I was before. It boots pretty fast - not sure how much ram I have - either 1 or 2 gig and I do recall the board is an AMD running a Sempron chip. I think it is a socket 754 but not sure - I'd have to open it up to look. I added a couple USB extensions that mounted in the side wall of the cabinet so now I have 3 working USB ports (part of my original upgrade). The only other thing I've had to do was replace the VFD which died abruptly about 6 months ago. All in all I have about $1K in this machine. Makes it really hard to spend the $2250 for the allin1 upgrade. Yes this does have the pendant - it is a little rough - the cycle start button is very well worn. I'll take a few pics of my machine and post them.

    Dan

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