547,565 active members*
2,004 visitors online*
Register for free
Login
IndustryArena Forum > CNC Electronics > General CNC Machine Related Electronics > Need 2nd opinion on Wiring diagram.. proximity - isolation - lpt.
Results 1 to 7 of 7
  1. #1
    Registered
    Join Date
    Jan 2018
    Posts
    925

    Need 2nd opinion on Wiring diagram.. proximity - isolation - lpt.

    Hello fellow members.
    Just want to get a 2nd opinion on this wiring diagram below.
    12 proximity sensors going into a 12 channel isolation board at 24v.
    Then going out of the isolation board at 5v.
    Then going from board directly into an input based LPT port of my cnc controller.


    Sensors: NPN, NC, operating at 24v.
    Isolator board designed for 24v/in & 5v/out.
    LPT is port 5 of a UC300eth controller running at 5v.

    Diagram:





    Yes it would be easier to get a bi-directional bob for it but we're talking about the u.k. here.
    You can't get Jack.
    (Anyway. The multi isolator boards look neater and are easier to get)

  2. #2
    Registered
    Join Date
    May 2016
    Posts
    2

    Re: Need 2nd opinion on Wiring diagram.. proximity - isolation - lpt.

    Quote Originally Posted by dazp1976 View Post
    Hello fellow members.
    Just want to get a 2nd opinion on this wiring diagram below.
    12 proximity sensors going into a 12 channel isolation board at 24v.
    Then going out of the isolation board at 5v.
    Then going from board directly into an input based LPT port of my cnc controller.


    Sensors: NPN, NC, operating at 24v.
    Isolator board designed for 24v/in & 5v/out.
    LPT is port 5 of a UC300eth controller running at 5v.

    Diagram:





    Yes it would be easier to get a bi-directional bob for it but we're talking about the u.k. here.
    You can't get Jack.
    (Anyway. The multi isolator boards look neater and are easier to get)
    Your schematic is correct. You should label port "i/o port 5" instead of LPT as it is internally configured as an i/o port and not a printer port. Without knowing that, it can be confusing to the reader.

  3. #3
    Registered
    Join Date
    Nov 2012
    Posts
    1131

    Re: Need 2nd opinion on Wiring diagram.. proximity - isolation - lpt.

    What is the purpose of the diodes in series with the pull-up resistors?

    Why do the outputs of the proximity sensors even need pull-ups? They have open collector outputs; a pull-up resistor would only make the transistor work harder.

  4. #4
    Registered
    Join Date
    Jan 2018
    Posts
    925

    Re: Need 2nd opinion on Wiring diagram.. proximity - isolation - lpt.

    Quote Originally Posted by CitizenOfDreams View Post
    What is the purpose of the diodes in series with the pull-up resistors?

    Why do the outputs of the proximity sensors even need pull-ups? They have open collector outputs; a pull-up resistor would only make the transistor work harder.

    They're just generic boards I got.
    The open collector side diode lights to show whether power is present to the isolator diode (active) or not (switch tripped).
    Pull up diode lights to show the active isolators collector is sending fault to the ttl i/o input.

    Helps with fault diagnosis for one thing. If open collector lights up but pull up doesn't, this shows there's a fault either with i/o input or isolator itself.
    This can prevent you doing machine damage I guess.

  5. #5
    Registered
    Join Date
    Nov 2012
    Posts
    1131

    Re: Need 2nd opinion on Wiring diagram.. proximity - isolation - lpt.

    Oh, I did not realize those were light emitting diodes. Makes sense now.

  6. #6
    Registered
    Join Date
    May 2016
    Posts
    2

    Re: Need 2nd opinion on Wiring diagram.. proximity - isolation - lpt.

    dazp1976 could you please, give a brief description of your project: servo, stepper, closed/open loop, amplifier, motors, tool, special purpose, new, retrofit etc. I am curious as to the performance you get from this controller.

    20 years ago, a friend of mine purchased a low cost control package for a lathe. It turned out to be a complete piece of junk. The control could not properly interpolate linear or circular, and the motors (stepper) were rough and weak, the control software HMI was unalterable and too cumbersome for real shop work. I hope things have improved since then and that this is a well thought out control. My suspicions is that UC300eth it is just a pc on a chip using software to drive step and direction thru one of the LPT ports.

    I used Indexer LPT software to retrofit a VMC and was happy with the results. Not trying to plug any product but to make you aware of possibilities.

  7. #7
    Registered
    Join Date
    Jan 2018
    Posts
    925

    Re: Need 2nd opinion on Wiring diagram.. proximity - isolation - lpt.

    Quote Originally Posted by Camdo2 View Post
    dazp1976 could you please, give a brief description of your project: servo, stepper, closed/open loop, amplifier, motors, tool, special purpose, new, retrofit etc. I am curious as to the performance you get from this controller.

    20 years ago, a friend of mine purchased a low cost control package for a lathe. It turned out to be a complete piece of junk. The control could not properly interpolate linear or circular, and the motors (stepper) were rough and weak, the control software HMI was unalterable and too cumbersome for real shop work. I hope things have improved since then and that this is a well thought out control. My suspicions is that UC300eth it is just a pc on a chip using software to drive step and direction thru one of the LPT ports.

    I used Indexer LPT software to retrofit a VMC and was happy with the results. Not trying to plug any product but to make you aware of possibilities.

    Well. You'll probarbly say it's a stupid idea but....
    UCCNC & Mach3, limitation is 6 axis + spindle.
    So I'm looking at the option of a 12 tool carousel changer project without having to lose an axis to run it.

    Using analoge 0-10v output #2 to spin the carousel motor and one of the 12 sensors for each tool.
    Output#2 spins it and stops when it triggers a sensor for a particular tool, and so on.
    Yes it's likely I can only spin in one direction using the analoge, so going from tool #1 to tool#12 will take more time.

    I could look into other softwares that run more than 6 axis but the costs go up a bit.
    It's just to see if it'll work tbf. And it is a distant future away.

Similar Threads

  1. Npn nc proximity sensor in series diagram
    By silvs in forum General CNC Machine Related Electronics
    Replies: 16
    Last Post: 03-07-2018, 11:09 AM
  2. Proximity sensor wiring
    By Lindzr in forum Automation Technology Products
    Replies: 2
    Last Post: 08-16-2017, 01:29 AM
  3. LPT Opto isolation BOB
    By shulio in forum General CNC Machine Related Electronics
    Replies: 0
    Last Post: 03-12-2009, 01:01 AM
  4. Wiring For Proximity Switches
    By Mcyoda in forum General CNC Machine Related Electronics
    Replies: 3
    Last Post: 08-05-2008, 03:20 AM
  5. PCB Trace Isolation - Minimum Track and Isolation
    By ahoodlum in forum General CNC Machine Related Electronics
    Replies: 11
    Last Post: 09-26-2006, 05:02 AM

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
  •