PMDX-179-PAN Probe Triggered Light Always On

[qahrens]

I have a PMDX-126 with a SmoothStepper connected to a PMDX-179-PAN and using Mach4.  All leds on the PMDX-179 are working correctly (Emergency Stop, Outputs Enabled, Step Activity, Control Power), but the Probe Triggered led is constantly on.  I am attempting to setup a simple touch probe with the GND touching J12-Pin 15. 

PMDX-126 JP5: Off
PMDX-126 dip switches all closed (not in merged input mode)

ESS Config
Pins Config-> port #1 - Pin 15: active low (named probe)
Input Signals-> Probe (G31 or G31.0) set to the ESS pin
Probing-> "All other probes probes will be ignored during probing" is checked

Mach4 Config
Input Signals-> Probe is checked and mapped to the ESS pin

In machine diagnostics the probe input signal lights up when Pin 15 is touched to GND and the Probe Triggered led goes out.  Is it possible somehow for the Probe Triggered led to illuminate when Pin 15 is connected to GND instead of turning off when Pin 15 is connected to GND?

Thanks,
qahrens

[Steve Stallings]

The "Probe Trigger" light on the PMDX-179 was designed for a digitizing
probe, which has the reverse action of a touch off probe. Your could get
it to behave as you wish by enabling the "Merged mode" for probes and
move your touch plate to the other input. You will need to put a jumper
in place on the old input point so that it is not always providing a signal,
and also reverse the polarity in Mach4 or the SmoothStepper setup. I am
not sure how it is done under Mach4 with the SmoothStepper plugin.
 
If the LED on the Machine Diagnostics page lights up when you touch the
ground to the probe input, that should be correct. The LED on the PMDX-126
should be off until you touch the probe input to ground.

[qahrens]

Thanks Steve that did the trick.  On the PMDX-126 I moved dip switch "config 4" to the open position to put the board into "merged inputs" mode.  A jumper was connected between J12 GND and "15" to hold that signal low.  Touching J11 "H" to GND now causes the "probe triggered" led on the 179 panel to light up (and it is off otherwise).  ESS plugin config in Mach4 now has Port #1 pin 15 changed to active high.  Mach4 also sees the probe as triggered when touching J11 H to GND.  It can be a little confusing because the signal is applied to J11 H, which is actually Port #2 pin 15, but Mach4 sees the signal on Port #1 pin 15 due to the merged inputs mode.

[Walter]

The "Probe Trigger" light on the PMDX-179 was designed for a digitizing
probe, which has the reverse action of a touch off probe. Your could get
it to behave as you wish by enabling the "Merged mode" for probes and
move your touch plate to the other input. You will need to put a jumper
in place on the old input point so that it is not always providing a signal,
and also reverse the polarity in Mach4 or the SmoothStepper setup. I am
not sure how it is done under Mach4 with the SmoothStepper plugin.
 
If the LED on the Machine Diagnostics page lights up when you touch the
ground to the probe input, that should be correct. The LED on the PMDX-126
should be off until you touch the probe input to ground.

I know the original poster (qahrens) had used the quoted solution successfully; however, I wanted to present an alternative solution for those that are just now encountering this issue.  This solution does not require the PMDX-126 to be configured into "Probe Merged Inputs" mode, nor require an extra input pin from the PMDX-126, but it does require an additional 12V relay, which are fairly inexpensive. 

I purchased the PMDX-179_EXT and made a remote status panel very similar to the PMDX-179_PAN. 

Attached is the wiring diagram for my solution.  If you would like to implement something like this, you'll need the following items (most if not all are available on Amazon):

  1.  A small metal box (search for: Aluminum Econobox) large enough to mount 8 - 12v LEDs and a switch (items 2 and 3)
  2.  8 - 12V LEDs (my color selection is in the attachment)(search for: Indicator Light 6mm 1/4" Waterproof IP65 Metal Signal Lamp 12V-24V AC/DC LED)
  3.  A small momentary SPST button (search for:  Momentary Stainless Steel Metal Push Button Switch)
  4.  A 12 wire cable (search for: 22 AWG 12 Conductor Stranded Cable)
  5.  A 12 pin aviation connector to connect remote status panel to the CNC Control box (search for: Metal Aviation Connector M20 - 12 pin) (alternative: Nylon Cable Gland)
  6.  Nylon Cable Gland to connect cable to remote panel box (item 1) (search for: Nylon Cable Gland)(alternative: could also use an aviation connector)
  7.  12V relay (search for: 12V Relay Module with Optocoupler High or Low Level Trigger)

Notes:

  1.  The 8 LEDs cannot draw more than 100 mV; the ones I got on Amazon drew ~2.5 mV each. Otherwise, an external 12V power supply will be need.
  2.  If a LED on the remote status panel is being used for the Motor Power:
      a.  PMDX-179, JP1 will need to be set to External, after first testing with the on board LED
      b.  The GND for the Motor Power and Test/Reset Switch is NOT the same ground used by the LEDs on J3 (PCgnd) and must stay isolated
      c.  Motor Power Supply needs to be 80V or less
  3.  12V Relay needs to be configured to trigger "Low"
  4.  Due to parallax error of the PMDX-179 image in the wire diagram, lines were added to point the silkscreen print on the PCB to the correct terminal location
  5.  The PMDX-179 on board "Probe" LED will stay lit when the probe is not activated (i.e., pin 9 of PMDX-126 J12 (labeled "15") is connected to ground); however, if the relay is connected correctly, the "Probe" LED on the remote status panel should not be lit until pin 9 of PMDX-126 J12 (labeled "15") is connected to ground.