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M3 Turns Relay off if 'S' value is not Max

Discussion in 'OpenBuilds Bug Report' started by Jacob Gad, Nov 16, 2020.

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  1. Jacob Gad

    Jacob Gad New
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    Thank you for the help :)
    I have my VFD connected with the relay on the blackbox controlling the DCM to FOR connection. When I run M3 S2400 the relay trips and connects DCM and FOR like it should. M5 also turns the relay off and disconnects DCM and FOR like it should.

    ISSUE:
    When I run M3 S12000 or anything less than M3 S1800 the relay stays off and does not connect DCM to FOR. furthermore if I run M3 S2400 which successfully turns the spindle on and sets the speed, but then run M3 S12000 the relay turns off, turning the spindle off.

    As I understand it this relay should just turn on to any M3 command and turn off to any M5 command regardless of the speed set.
     
    #1 Jacob Gad, Nov 16, 2020
  2. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    Only if you have the Jumper set up on VFD/Enable mode:

    See docs:blackbox:jumper-relay [OpenBuilds Documentation] (refer to the bottom section "Respond to Spindle Direction Commands / Use with Grbl's "USE_SPINDLE_DIR_AS_ENABLE_PIN")
    If you want to use it as a spindle enable, you also have to refer to gnea/grbl and recompile Grbl with #define USE_SPINDLE_DIR_AS_ENABLE_PIN to work as expected

    BUT NB: You can also setup the VFD parameters to not need the relay at all. Just using 0-10v signal, with DCM/FOR hardwired. Then you can use the default configs - as described in threads linked from docs:blackbox:connect-vfd [OpenBuilds Documentation]
     
    #2 Peter Van Der Walt, Nov 16, 2020
  3. Jacob Gad

    Jacob Gad New
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    Thank you Peter that was an amazingly fast response.
    I have moved the jumper cable to VFD / Enable Mode

    Unfortunately there seems to be an issue, M4 turns the relay on and M3 turns the relay off, this is reversed.
    Also is there no way to have M5 turn the relay off?

    Thanks again :)
     
    #3 Jacob Gad, Nov 16, 2020
  4. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    As mentioned: Needs a recompile
    Can also be changed by recompiling : gnea/grbl

    So much easier just to config the VFD correctly instead :)
     
    #4 Peter Van Der Walt, Nov 16, 2020
  5. Jacob Gad

    Jacob Gad New
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    Done deal makes sense, thank you Peter.
    I ended up following the recommended config and set the VFD's minimum frequency to zero, and hard wiring DCM to FOR.
    Works great now
     
    #5 Jacob Gad, Nov 17, 2020
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  6. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
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    :) Good stuff! Yeah, so much simpler man!
     
    #6 Peter Van Der Walt, Nov 17, 2020

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