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Black Box no limits or probe inputs

Discussion in 'General Electronics' started by james Penty, Oct 20, 2021.

  1. james Penty

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    Hi all, first post here, I have made a CNC plasma bed (not even turned on the plasma torch yet) I have all the motors running and scaled but I'm not getting any inputs from the induction proxy limits and touch probe the IFM sensors are lighting up indicating 24V and 0V are present and 24V is also going down the sig wire when activated but nothing shows in openbuild control on the troubleshooting page looking at the limits states.

    I have also tried with a NO basic switch without success.

    the unit was first powered up with the 5V/24V jumper still in 5v mode that's now been changed to 24v. I have read this shouldn't damage the inputs correct?

    any advice is welcome, I'm thinking it's firmware.

    some photos of my build are attached.

    Cheers.
     

    Attached Files:

  2. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    Might be your sensors themselves (wrong type, wrong spec, etc. BlackBox need NPN type)

    Happy to check if you post the datasheet for the sensors you have.

    If you are unsure, and need to validate the BlackBox works fine: Test with a little jumper wire between SIG and GND simulating a regular Limit switch while watching the Troubleshooting tab in CONTROL. This will allow you to eliminate sensor vs controller to decide the way forward.
     
    crispin likes this.
  3. james Penty

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    Thanks for the response, using IFS204 - Inductive sensor - ifm electronic these are PNP never even gave PNP/NPN a thought, I always use PNP on all PLC systems I build, I might have some NPN Proxy on stock to try but doubtful I will have 4 the same.
     
  4. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    You do need NPNs yes, for the default configuration at least, as we need to pull SIG to GND when it triggers.

    You "might" be able to use PNP, if you add a Pulldown resistor externally to ensure the untriggered state has SIG pulled LOW. "Might" as we haven't tested it.

    As-is its either floating (un-triggered) or at 24v (triggered) and since we also have onboard 10k pull-ups (expecting either NPN or normal switches) your sensor effectively looks like a HIGH for both states. Either the sensors is keeping SIG at 24v (triggered) or our onboard pullup is (un-triggered: sensor output floating, onboard pullup keeps it high)

    You can configure whether the HIGH is seen as triggered (PNP), or the LOW is seen as triggered (NPN, switches wired per our docs) using the Limits Invert parameter, but first you need to get two states out of the sensor - which at present you do not.
     
    james Penty likes this.
  5. Yves HAEMMERLI

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    Hi Peter,
    I just found this post from 2021 that I can use to ask my own question about proximity sensors and Blackbox X4 controller.
    Yesterday, I finished the cabling of my DIY plasma cutter CNC and wanted to test things one after the other. The first thing I wanted to test is if X, Y and Z axis end stop NPN magnetic proximity sensors are operationg as expected. Withoput changing any default settings in the Openbuilds Control software, I realized that proximity sensors are not powered from the controller. I correctly set the jumpers for 24V however. Is it a normal default behaviour ? What shoul I change in the software to enable 24 power on sensors ?
     
  6. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

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