Estop for external driver? (aftermarket add on)

What is the recommended estop handling for an external stepper driver? I’m using a DM542T.

Will this work?

Take the Masso ES output and send that to Enable +, Grnd to enable - ?

Will it break anything?

Is there a standard location on the 10 pin connectors for the Enable+ and Enable- (aka gnd?)

Based on : EStop Wiring
" A special output signal “ES” (E-Stop output) is available on the outputs terminal. This output is internally hardwired to the E-Stop button signals and goes LOW when the E-Stop button is pressed.

  • The output voltage of this output is 2.3 volts and drops to 0v when the Estop button is pressed."


Driver doc reads opposite of ES output voltage. + voltage to disable. Also the voltage range is not compatible.

“Enable Connection: (default no connection)
(1) Optically isolated, differential. (2) Disable the drive by 4.5- 24V input connection; enable the drive by 0-0.5V connection(3) ENA signal requires advance DIR signal minimum 5μs in single pulse mode
(4) Enable time to be at least 200ms”

I measured the ES signal as 1.7 volts. It goes to the OneFinity controller box. I did not open that box up.

Onefinity: Are schematics available for the current (not intentional) e-stop wiring in the Elite series?

What are you trying to accomplish by plugging in an auxillary stepper driver?


Use existing stepper motor on 4th axis (rotary).

Why not plug your driver into the A

Onefinity has created a little confusion on “A.” The A wire/connector that goes between Masso and Onefinity control box and the A Axis on masso. I’m using the A axis through the stepper driver. Stepper works well. Problem is stopping the driver when the Estop is hit. What is the standard approach for Estop handling on an external stepper driver?

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Hey Jd22,

Sorry if I can’t follow, but what has Estop to do with a stepper driver?

As far as I understand this and this, the ES output in the example is wired to one relay which has the purpose to force all others relays going off when an Estop condition occurs.

However I don’t know to what the relays on the Elite are wired. Do you know it?

I have a G3 - not Touch - and have my ES output wired to a Masso relay module which controls the ENA of my drives. See below diagram from the online Masso manual:

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Hey Tom,

yes, I saw this diagram behind the link. But to which devices are the relays in the Elite wired? Are there relays free to use?

Okay, axis A is used for the additional stepper driver, there are the step± and dir± and ena± lines. And if you wire ena± to the ES relay it will be disabled when someone hits Estop.


Thanks for helping me on this.

When the estop is hit, I want the rotary stepper to be off. My first thought is the 36v power comes from the elite control box and the estop would just drop the supply voltage to 0. That does not occur. So my next thought was to wire the estop hit signal (ES or some hardwired ES alternate) to the ENA on the external stepper driver. That would disable the stepper. Then I found the ENA on the driver I bought is really a NOT ENA. Active low. Hence here we are.

The Onefinity black box remains an unknown, to me at least, and I don’t remember if anyone with an Elite has opened theirs to share the components and wiring. I suppose that makes building your own electronics enclosure a benefit in situations like this when you want to add functionality to a prefabricated system.

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The ES output of masso is connected to an optocoupler in the power supply box to switch off router and vac relays. As ES is a very weak output (it is derived directly from internal processor logic) you can’t connect anything else here.

For all enable inputs on the masso steppers onefinity does not follow masso’s recommendation, instead all enable pins are directly connected to the e-stop switch on terminal ESTOP 2.

You maybe want to get that signal to form your enable. But as mentioned above the logic of external stepper drive DM542 follows is “high” = disable, so you need a relay module or other electronics to invert the signal from e stop switch. In addition, depending of driver version, you need a 5V signal or a 2K 1/4W resistor to drive the enable input. Consult your manual of your specific DM542T for that, there are different versions out in the field.


Hey jd22,

okay I just Read the Fine Manual and as far as I can see, the Elite Masso G3 Touch has neither the relay module nor is A axis available at the back. I understand better.

Did you buy the relay module or what do you plan to do?

Hey Joergen,

thanks for the clarification.

Estop 1 and 2 are inputs. How exactly do you mean that the ena± of the stepper drivers are wired to it?

Welcome to the forum! :wink:

Hey jd22,


Which A-axis wire/connector?

They call the power cable A

Hey Chris,

and it makes axis A available?

No. It’s the power cable/port from the black box to the touch box and provides power to the g3.
A axis is on g3 and doesn’t have an access port on the touch box. There is an available 2 pin power port on the black box

@ Aiph5u: They are pragmaticly use the terminal to connect the wires from e stop switch to the enable inputs of axis motors. The inbuild-driver-stepper have a single ended enable input with high = enable.