Need Help! Sourcing or Sinking I/O's


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Thread: Sourcing or Sinking I/O's

  1. #1

    Default Sourcing or Sinking I/O's

    Hello all!

    I have a vintage 1999 Techno-Isel gantry type machine with a servo system.
    It runs on a PC card and a SRVBOX2 controller (+/-10V amplifiers).
    In order to upgrade the PC card and keep the drives, it seems that I need to know whether the I/O's are sourcing or sinking.
    This is nearly universal regardless of which motion control product I'm looking at.
    Does anyone know enough about this control to tell if it has sourcing or sinking circuitry?
    Does anyone know how to test for source or sink?

    Thanks for your consideration

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  2. #2
    Community Moderator Al_The_Man's Avatar
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    Default Re: Sourcing or Sinking I/O's

    You just need to look at the I/O device supply, if one lead is power, they are sinking inputs, if ground, then it is sourcing inputs.
    The device itself is the opposite, IOW a source device uses a sink input, and vice-versa.
    Al.

    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.


  3. #3

    Default Re: Sourcing or Sinking I/O's

    Thanks Al,
    Just to understand... my limit switches are being supplied +24V, therefore the supply is sinking input. And, I would need a sinking BOB.

    Is that correct?



  4. #4
    Community Moderator Al_The_Man's Avatar
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    Default Re: Sourcing or Sinking I/O's

    Sounds so, if the limit switch has the 24v+ve then they are a sourcing device, which would require a sinking type input.

    Attached Thumbnails Attached Thumbnails Sourcing or Sinking I/O's-sinksource-pdf  
    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.


  5. #5
    Member ericscottf's Avatar
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    Default Re: Sourcing or Sinking I/O's

    What are you looking to accomplish?

    The other engineer here at Armor designed that board - we can help.

    Eric

    Eric Feldman - Design Engineer, Programmer
    Armor CNC - http://www.armorcnc.com Support hours: 7am thru 10pm EST, 7 days a week


  6. #6

    Default Re: Sourcing or Sinking I/O's

    Thanks again Al!
    Your attachment expands my understanding of the issue.
    Actually I just came across some Techno documentation that describes one pin (an auxiliary output) on the controller as Sinking output (negative logic).
    Would manufacturers commonly mix positive and negative logic?
    Perhaps I don't understand their circuitry all that well yet.



  7. #7

    Default Re: Sourcing or Sinking I/O's

    Hello Eric!
    I'm looking to overcome the hardware and software limitations of the obsolete system without breaking the bank.
    Upgrade the machine to have 4th axis plus spindle control while keeping the older drives and motors.
    All of the aftermarket servo systems I've researched invariably require the sink/source issue to be addressed for proper BOB choices and/or wiring.



  8. #8
    Member ericscottf's Avatar
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    Default Re: Sourcing or Sinking I/O's

    If you have the PCI card (not the ISA card), then the machine as is can run on windows 10, likely already has spindle speed control, and you can easily add a 4th axis without changing the controller.
    What other limitations are you looking to overcome?

    Eric

    Eric Feldman - Design Engineer, Programmer
    Armor CNC - http://www.armorcnc.com Support hours: 7am thru 10pm EST, 7 days a week


  9. #9
    Community Moderator Al_The_Man's Avatar
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    Default Re: Sourcing or Sinking I/O's

    Quote Originally Posted by ShopWorks07 View Post
    Thanks again Al!
    Your attachment expands my understanding of the issue.
    Actually I just came across some Techno documentation that describes one pin (an auxiliary output) on the controller as Sinking output (negative logic).
    Would manufacturers commonly mix positive and negative logic?
    Perhaps I don't understand their circuitry all that well yet.

    In some cases the logic is fixed, either one or the other, you can also run across optional/flexible types where the inputs can be configured as needed, but in most cases that cater to the DIY field, they are mainly fixed, one or the other.

    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.


  10. #10

    Default Re: Sourcing or Sinking I/O's

    Hello Eric,

    I've been researching this and I'm coming to the conclusion that If I want to keep to my wishlist I'll have to move away from the Techno-Isel system.
    Because, the PCI or ISA cards I'm limited to just the 4 axes in the SRVBOX2.
    With after-market solutions I have additional axes available, even mix and match amplifiers.
    I would also get on-board MPG support.
    With Techno there is no possibility of spindle encoder and no 'on-the-fly' tool length and diameter offsets.

    ProCNC may support higher level machining but I doubt it would run on these older cards. And I doubt it is within my budget.
    Galaad may work but it uses Kay for for 4 and 5 axis interpolation. Kay says it will only run steppers. There is nothing on the Galaad site that says differently.

    So, back to the question; Does SRVBOX2 require sinking or sourcing supply signals? and are they positive or negative logic?

    BTW; There are ISA slot computers being made that will support Windows 10 for under $1000

    Thank you for your consideration



  11. #11
    Member ericscottf's Avatar
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    Default

    Quote Originally Posted by ShopWorks07 View Post
    Hello Eric,

    I've been researching this and I'm coming to the conclusion that If I want to keep to my wishlist I'll have to move away from the Techno-Isel system.
    Because, the PCI or ISA cards I'm limited to just the 4 axes in the SRVBOX2.
    With after-market solutions I have additional axes available, even mix and match amplifiers.
    I would also get on-board MPG support.
    With Techno there is no possibility of spindle encoder and no 'on-the-fly' tool length and diameter offsets.

    ProCNC may support higher level machining but I doubt it would run on these older cards. And I doubt it is within my budget.
    Galaad may work but it uses Kay for for 4 and 5 axis interpolation. Kay says it will only run steppers. There is nothing on the Galaad site that says differently.

    So, back to the question; Does SRVBOX2 require sinking or sourcing supply signals? and are they positive or negative logic?

    BTW; There are ISA slot computers being made that will support Windows 10 for under $1000

    Thank you for your consideration
    It depends on which inputs you're talking about. Home inputs are npn, the others are pnp.

    5 or more axes or spindle encoder, you'd need to use a different controller to get those features. The others are possible in the windows version of the interface.
    Imo, galaad and Kay are an exercise in suffering to use. They're the software equivalent of a Kafka novel. Use Mach 3/4 if you're going to go this route.

    Do you have the Isa card or pci?

    Eric

    Eric Feldman - Design Engineer, Programmer
    Armor CNC - http://www.armorcnc.com Support hours: 7am thru 10pm EST, 7 days a week


  12. #12

    Default Re: Sourcing or Sinking I/O's

    Hello Eric,

    Thank you helping, but I'm not sure that knowing the answer makes the decision any easier :-(

    I had no intention of going the Galaad route. I sounds too 'mickey mouse'. Only offered it for comparison.
    Mach 4 seems a reasonable choice for after-market control software. LinuxCNC would be a runner-up and perhaps 'Kafkaesque'.

    Regarding the Techno interface - the docs for Build #400 (LC router) show only tool length sensing. Haven't found any description of Build #423.
    However, I just dug deeper and came across 'Techno CNC Interface V2015.1'. It clearly has offset capabilities, G40, G41, G42.
    Would it run on my system with an ISA computer upgrade. Or what else would need replacement?

    Why I'm thinking of changing out the card (BTW: ISA slot) is because of the ability to control more axes, and have on-board MPG support.
    More importantly I would also have the choice of using servo or stepper drives in a mix/match fashion.
    Then, should a drive or motor fail I'd have replacement choices and the ability to upgrade those components as well. Technology has come a long way in 20+ years
    The Techno Setup Manual that came with the machine has pinouts for the SRVBOX2 and I should be able to map that to an ethernet controller.
    Albeit, with much perseverance and a bit of help.

    I did try to explore upgrading the Techno controller card but found little to no info. The Techno docs call for a H20T43-PCI403UP.
    No info on why that part number is any different than the standard PCI card. H20T43-PCI403 or KT
    Sounds to me like the older SRVBOX2 has compatibility issues and maybe some limitations.

    I will admit perhaps my wishlist for this little machine is way too expansive, but that's my starting point.
    If I choose to upgrade the card and computer how far will that technology take me?
    I'm facing the fact that the technology is old at the same time realizing that by keeping with it, I could be diverting funds from the inevitable upgrade.
    Besides I still have to spend on devices (spindle,VFD, etc..)

    It's all a balancing act.

    Many thanks,





  13. #13
    Member ericscottf's Avatar
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    Default Re: Sourcing or Sinking I/O's

    I'll try to get to all your questions, if I miss any, re-ask or email me directly.

    I wrote a cutter-comp plugin for the techno software long ago on my own time, it was never distributed with the software, that's why it isn't in the manuals. It is for tool wear compensation, not full compensation off centerline. I see little reason to comp at the machine these days, a good workflow from CAM to the machine is the better way to do things, except for some really specific circumstances involving tolerances that the mechanics of that machine simply don't support.

    The "2015.1" upgrade is not for your controller, it's for the retrofit kit that the current owners of techno were selling awhile back (it's a mach/wincnc/something like that gut-and-replace for big $$ last I heard).

    We have an MPG controller for your system (when in windows, not dos of course, so you'd need the PCI card). Check out the revolver on our website - Home | Armor CNC - it's much nicer than the standard mach MPG with full color touch screen, but definitely more expensive than the $60 bare-bones units you can get for mach.

    Your servobox 2 may be old, but it's still capable of pretty much anything - it's a servo controller, which is a big deal in a world that's becoming increasingly dominated by cheap stepper solutions. If possible, you should stick with servos in my opinion.

    Unless you get an ethernet controller that can take in the encoder feedback from the motors and put out analog voltage for servo amp control, you aren't going to map to the existing box. it does not take pulse/direction. Certainly it could be done with a pulse/dir board w/ encoder tracker. Probably way more work than it's worth unless you're doing it for the fun of doing it.

    The upgrade to PCI for your machine is the PCI403 card. We have them in stock and fully support them.
    There are no compatibility issues with your Servobox2 and the PCI Card, they work well together and we upgrade users from ISA to PCI often. Original techno sold way way more PCI cards with that servo box than ISA cards.
    If you upgrade the card and computer, you'll have a servo system (potentially) running windows 10. Fairly modern to me, and when compared to pulsed stepper systems, it's no contest.

    FWIW we do offer a mach 3/4 retrofit kit as an option, but we reserve it for customers who need it for reasons like matching workflow between a techno they just acquired to machines they already had that run mach 3/4. Otherwise we shy away from doing it b/c of the whole step/direction nature of mach. It bugs the heck out of me that if you e-stop a machine running mach while it is in motion, you lose position and have to re-home. I've looked into working on a plugin for mach that could query a step-servo amp to get encoder position in order to restore telemetry after loss, but it looks like more work than it's worth. I'm shocked nobody else has done it (as far as I can tell)

    We're happy to help with whichever direction you go in. If you do wind up having no need for the servobox2, please contact us and we'll make an offer for it.

    Let me know if you have any other questions.
    Eric

    Eric Feldman - Design Engineer, Programmer
    Armor CNC - http://www.armorcnc.com Support hours: 7am thru 10pm EST, 7 days a week


  14. #14

    Default Re: Sourcing or Sinking I/O's

    Hello Eric,

    Thanks for straightening me out on the Techno features! At this point in the discussion it might be better to continue privately.

    However minor, I do take issue with using CAM for cutter comp. That may work well for an owner/operator of a small shop or you're programming a machine from MDI, But coming from a job shop/production environment, I think that a shop floor manager would never use a programmer's time to make those changes all day long.That kind of hand holding would be inconceivable just from the downtime perspective. It's the programmer's job to make programs and the machinist's job to make the parts to spec. Ergo, cutter compensation.

    I'll contact you directly to see what options might suit the retrofit parameters and how we may collaborate on this.




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