Author Topic: ESS Estop active low, PMDX-126 Estop active High, how to overcome this?  (Read 3090 times)

Got2cnc

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Hi all,
 ESS + PMDX-126 + PMDX 107, Mach4.
 In the ESS Plugin ESS needs to have pin outs Estop, active low. The PMDX-126 Estop works active high.
In my understanding, for a start these should be on separate pin outs.(?)

The PMDX-126 Estop is port 1 pin 10.
 Any other available input pin can be used for the ESS Estop signal.

I added a second switch to my Estop button so that two separate pins could handle the ESS Estop signal, and the PMDX-126 Estop signal.

Is it correct that the voltage for the pin chosen for the ESS has to be "sinked"? ("Sinked" according to section 13.0 PMDX-126c users manual, "low must be able to sink 6 mA at less than 0.8v")
And what is the best practice for executing this "sinked" voltage?

I see that now I am getting an Estop condition from the ESS when the button is not pressed, and an Estop condition from the PMDX-126 when the button is pressed.

 Thank you in advance.

Steve Stallings

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The PMDX-126 is designed to signal E-Stop in active High mode because we
wanted an E-Stop to occur is the parallel port cable became unplugged.
Most inputs including real parallel ports and the ports of a SmoothStepper
have pull-up resistors what will go High if the input is disconnected.

The SmoothStepper can be configured for either Active High or Active Low
inputs. I think there can be some confusion in the case of Mach4 because
both Mach4 and the SmoothStepper plugin offer competing settings for this
parameter. One of their videos mentions the possibility of a "double negative"
if it is set in both places. Please consult with Warp9TD support if you need
assistance with this setting.
Steve Stallings
www.PMDX.com