Z Probe Help

  • Hi

    The Z probe that I have doesn't have the identification sticker on it, but I believe that it is an SN04-N ( NPN NO ),
    but It could be an SN04-N2 ( NPN NC).
    I believe it to be normally open because if I hook it up as a normal endstop switch it will work as a open switch.

    The problem is when I hook it up as per WIKI instructions, Blue wire to ground, Brown wire to 5v, Black wire to cathode end of a
    Bat85 Schottky diode, anode end to E0 stop pin.
    The probe when triggered reads 0 on the Duet Web Control, and reads 1000 when untriggered.
    That makes it seem like a normally closed switch. The wiki doesn't address normally closed probes, that I seen.
    If I change the M574 E0 S0 to S1, were I'm guessing that the S1 = active high endstops, nothing changes.

    So…What am I doing wrong?

    Here is my firmware settings

    ; Endstops
    M574 X1 Y1 S1 ; Set active high endstops
    M574 Z1 S2 ; Set endstops controlled by probe
    M574 E0 S0 (S1)
    M558 P4 H5 F360 T6000 ; Set Z probe type to modulated and the dive height + speeds
    G31 P500 X0 Y0 Z4 ; Set Z probe trigger value, offset and trigger height
    M557 X50:271 Y35:271 S20 ; Define mesh grid

    Thanks for any and all help.

  • administrators

    Add parameter I1 to the M558 command.

  • AH Ha!!
    Thanks dc42. That fixed it.

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