584,879 active members*
5,197 visitors online*
Register for free
Login
Results 1 to 6 of 6
  1. #1
    Join Date
    Nov 2008
    Posts
    26

    UC100 and C10 Bob

    Hello all,

    I'm putting together a CNC Mill using the CNCDrive, UC100 and CNC4PC C10 Bob. The firmwware on the UC100 is for UCCNC and it's the latest version.

    The issue I'm having is when the UC100 is unplugged or the PC is sleeping the outputs on the c10 are floating at around 2.7 volts. This is bad as it causes my stepper drivers to step at about 0.5ipm, and it's just not a single axis doing this it all three at the same time. I can't think of a way around the problem, I can't use the enable pin on the C10 because the outputs are disabled. I also can't pul anything up or down because the buffers seem to be in this tri-state of 2.7v.

    The machine performs perfectly when the PC is awake.

    Any ideas would be great.


    Edit: I just noticed that if I set pins 5 or 7 high on the UC100 the bob powers up if the machine isn't providing the C10 5v..

  2. #2

    Re: UC100 and C10 Bob

    How are you powering the C10? From the USB port?

    I would say that if you are running a machine, you should disable the power saving features for the USB port and probably the rest of the system.

    Arturo Duncan
    https://cnc4pc.com

  3. #3
    Join Date
    Nov 2008
    Posts
    26

    Re: UC100 and C10 Bob

    No,

    I'm powering the C10 with a dedicated 5V supply. I would encourage you take a set of devices from stock and see if the issue is repeatable.

    1. Provide 5V to the C10 and jumper the enable.
    2. Connect a UC100 to a pc running the latest version of UCCNC, update the firmware.
    3. Connect the UC100 to the C10.
    4. Then unplug the UC100 from the computer (edit: or shutdown the pc) , leaving the 5v supply connected.
    5. Measure the Ports 2-9 configured as outputs, in reference to ground.

  4. #4
    Join Date
    Mar 2003
    Posts
    35538

    Re: UC100 and C10 Bob

    The machine should not have power applied unless the PC is in control of it.
    Gerry

    UCCNC 2017 Screenset
    http://www.thecncwoodworker.com/2017.html

    Mach3 2010 Screenset
    http://www.thecncwoodworker.com/2010.html

    JointCAM - CNC Dovetails & Box Joints
    http://www.g-forcecnc.com/jointcam.html

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

  5. #5
    Join Date
    Nov 2008
    Posts
    26

    Re: UC100 and C10 Bob

    Quote Originally Posted by ger21 View Post
    The machine should not have power applied unless the PC is in control of it.
    That should not be a requirement, the machine should be disabled if the computer is powered off or the USB cable is unplugged.

    The BOB should not have the outputs floating, they should be at ground or at 5v. There is some kind of interaction with the C10 and UC100.that is causing this issue on my C10.

    The issue goes away if the UC100 is not connected to the DB25.

  6. #6

    Re: UC100 and C10 Bob

    Yesterday I took some boards on the bench and tried to replicate what you are seeing and was not able to. In all cases the outputs of the C10 gave a solid high or low, never an “in the middle voltage”.

    My thoughts with regards to what you are seeing:

    - Please keep in mind we have been making breakout boards for over 15 years and have been dealing with all kind signals from parallel ports and motion controllers. Long time ago we decided to aby by IEEE1284. Now days most motion controllers out there do not really comply with this standard, including the UC100. The problem in cases like this, is that IEEE1284 calls for pull-ups on the signals, that can cause a problem with pins going high when in the air.

    - My initial thinking in your case, is that your PC is sending residual voltage to the UC100, which may be sending frequency or making the output signals of the UC100 oscillate. It would be great if you could scope those signals.

    - While I agree with Gerry’s comment about the machine not having power while the PC is not in control, I would like to clarify or expand his comment to not just the PC, but all other control hardware/software. The power side is what should be off until the user/software/hardware are OK. This principle really applies to all systems, but it is implemented in different ways on each system. It is not the same to deal with a desktop machine than to deal with a system with dangerous DC servos (remember the old DC servos that could run away if they lost feedback form the resolver). What we recommend and implement in our breakout boards is:
    o All our breakout boards have an EN or External Enable input. The idea is that e-stop or other enable line of the system to be tied to this input. In simpler system like yours, you could just tie e-stop in parallel to this terminal on the C10 to hardware disable the outputs while e-stop is open.
    o Use a Safety Charge Pump, so it is not just the user (or other devices) allowing the system to activate, but the SCHP can make sure the software controlling the machine is indeed alive and well.
    o Use the output of the SCHP on the breakout board (which is already dependent on the enable line of the system) to drive power to the machine, or control to the main contactor, or power to the main power supply, etc…

    - Some additional Safety Features our boards have are:
    o Cable Disconnect Detection: The boards will disable the outputs if the breakout board loses connection to the ground on the DB25. This will disable the outputs if the cable is disconnected from the PC.
    o They have a green LED that will light when the when the outputs are enabled.

    In your case, I suggest you consider implementing this wiring for e-stop: http://cnc4pc.com/Tech_Docs/4_C10R10.pdf

    Let me know if you have any questions.

    Arturo Duncan
    https://cnc4pc.com

Similar Threads

  1. UC100
    By JohnHaine in forum UCCNC Control Software
    Replies: 4
    Last Post: 12-08-2018, 10:23 AM
  2. USB 3.0 vs. USB 2.0 for UC100
    By JukeBox in forum UCCNC Control Software
    Replies: 3
    Last Post: 06-18-2018, 09:20 AM
  3. UC100 Issues
    By jeff johnson in forum USB, RS232, PARALLEL etc
    Replies: 1
    Last Post: 12-29-2017, 02:42 AM
  4. Question about using UC100
    By gene8522 in forum UCCNC Control Software
    Replies: 4
    Last Post: 01-30-2017, 03:41 PM
  5. UC100
    By naijin in forum Australia, New Zealand Club House
    Replies: 5
    Last Post: 02-01-2016, 04:04 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •