Emergency Stop issue

Recently connected my 1F controller to my VFD in order to checkout the spindle functionality. I was able to start and stop the spindle using the touchscreen.
However I wanted to make a safety check. So I had the spindle running at 12,000 rpms and I hit the emergency stop button on the controller. The controller as well as the display immediately shutdown. The spindle and VFD however kept running.
I’m hoping someone knows the fix to stop the spindle when using the Estop button.

Mike Remphasized text

Hey Mike,

Yet I’m waiting for my Onefinity CNC including the Onefinity Controller (which is a variant of buildbotics.com Controller), so I can only be of limited help, but in Buildbotics Controller Manual it says:

4.1.3. Emergency Stop Button

A yellow and red “emergency stop” button is present in the upper right part of the screen on all pages. Clicking this button puts the controller in the ‘ESTOPPED’ state. When in the ‘ESTOPPED’ state, all motors and the spindle are disabled, all position and homing information is lost, and the yellow ring blinks between orange and yellow.

I’ve already thought about what this Emergency Stop Button does, but it is clear that electrically, this it is not a “real” Emergency switch:

:warning: The National Fire Protection Agency (NFPA 79) requires that the class of emergency stop button be determined through a risk assessment. The soft “emergency stop” button on these web pages and the estop pin (pin 23 on the DB25 I/O connector) are both software controlled, and cannot be used for safety. If your risk assessment requires an emergency stop button to be installed for safety purposes or mission critical applications, then Buildbotics LLC recommends installing a “listed“ hardware Emergency Stop button in line with system power.

I’m about to wire my control cabinet too. Usually you connect an Emergency Stop Switch to a safety relay such as the Omron G9SE (datasheet), which will then interrupt the power to the spindle in the most direct way possible (by hardware-triggering a Safety Input on the VFD, instead of the CNC Controller Software sending a command via RS-485/ModBus network).

Still, if buildbotics claims the that the spindle should be switched off when pressing the emergency switch, I believe it should send such a spindle stop command. Did you connect your VFD via PWM method or via RS-485?

Thanks for the great information.
I’m new to the cnc world but since I am starting, stopping and controlling the speed via the controller I assumed the Estop would be exactly that.
Yes I am using rs485.
I suppose that since the Estop stops the controller the X Y & Z will freeze and the power to the VFD could be shutdown without any damage being done.
Except of course losing project job mid stream.

I was doing these dry run tests prior to assembling the machine. Just ensuring that the VFD was operational through the 1F controller and the spindle was operating as advertised. So far so good.

Hey Mike,

since I don’t have the Controller here to see what it does, I can only assume things.

Buildbotics manual says “estop” button is software controlled, so I would assume it sends the command to stop the spindle the same way you send it when you click on stop spindle on the screen or when you send the M05 command which would stop the spindle. But it would not be powering down the VFD, this would need to be accomplished by an external safety circuit. And the safety circuit would not power off the VFD, but activate one of the Intelligent Terminals on the VFD which you would have programmed to serve as ISO 13849-1 Safety Inputs, or similarly programmed to initiate the spindle stop command (optionally with brake command).

(Source: Omron MX2 User’s Manual)

(Source: Hitachi WJ200 Instruction Manual)

Btw, using an external safety circuit would also allow to power off a trim router automatically when the Emergency Switch of the (external) Safety Circuit is pressed.

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I would check if the VFD has a parameter you can set that requires periodic messages from a controller to stay active.

Mine does, and I configured it that way, but it also needed me to wire up a reset button to provide a momentary on/off.

I wrote up my settings here Optidrive E3 VFD - #3 by AndyP. Look for “purpose 3”. Your VFD may have a similar parameter.

Hey Andy,

this looks like C076 and C077 on the Omron/Hitachi

Definitely 077. The other might be to handle deceleration. I configured mine to coast as decelerating caused the VFD to trip (I haven’t added a braking resistor). Coasting is pretty quick and meets my needs.

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