Calypso CNC User Forums

Hi there,
Again I'm not sure if this is a MSM question or just Mach3. If the latter, please ignore. I've posted in Mach3 support forum also.
Is it possible to customise what happens when Mach3 is E-stopped / reset, either via software button or via hardware input pin/switch?

I think currently when it is pressed all outputs are disabled in one go. This would normally be fine, however the reason I ask is because of how my spindle reverse is implemented.
Currently... I have 0-10V analog output to a VSD via a PWM speed output from Mach. Then I have two relays... one SGR // Spindle Go Relay, to enable power to the motor. Then a second relay SRR // Spindle Reverse Relay (a DPDT motor reversing relay) to determine the direction of rotation.

I've written M3, M4 and M5 macros to correctly handle the changeover from CW to CCW under all conditions safety. i.e. the logic and delays for spin up / spin down, and direction selection. Any wrong combination = bad news for the spindle drive.

This all works perfectly for now.
However when E-stop I have identified a potentially problem.
If the spindle is going CW // M3, and e-stop is pressed... Mach3 kills the outputs to all pins, the SGR is disengaged and the spindle stops / disabled.
HOWEVER... if the spindle is going CCW // M4 and the e-stop is pressed... Mach3 again kills all outputs (even the SRR relay). Which will case the relay to change over its poles and try and dump the energy stored in the running spindle.
This is obviously really bad.

So the question:
How can I get Mach3 to do it's e-stop / reset thing as normal with the exception of ignoring the state of one output?

OR... do I rip out the current spindle relay setup and try and implement the Mach3 spindle logic in timers and relays to make it "foolproof"?

All the best,
Dan

Hi,
I think that what you want to do is not possible in Mach 3. When mach gets told that an estop condition exists, it simply stops mach in it's tracks and the actions you are seeing are what (as far as I know) mach does. I am not aware of any ability to customize mach estop actions.

I will suggest that what you have described for your estop requirements strikes me as not very safe. It sounds to me like you are (or want to) depending on Mach to drop outputs for estop. That's not a safe design in my view. Remember that E-stop is short for Emergency-stop. It is my understanding that commercial requirements for estop (in many countries) require that all estop actions be accomplished with hard wired circuitry and software (I.e. Mach3) is NOT allowed to be part of the etop facility. Mach has been known to freeze up and not do anything - and you do not want a situation like that to essentially disable estop abilities for the machine.

I think you would be better off thinking of estop as a hardware design issue. The hardware design should (after the hardware is disabled, stopped, and locked out by hardware), as a nice gesture, inform mach that an estop condition exists (so the user interface will show that condition). But one should not do a system design that uses Mach to control estop actions. By the time mach drops outputs, it should not matter as the estop logic will have already forced control lines into appropriate states.

Re the spindle energy dump issue: you can handle that in hardware logic or you can ignore it. What is important is that the machine stop - and stop NOW when needed to. If the spindle has a problem from ignoring the possibility you identified, well, as long as life and limb were saved, estop circuits have done what they should.

Dave

Thanks Dave.
There are suitable hardware e-stops implemented already; it was just this interaction of the Mach3 E-stop causing issue.
After a bit of thought, I can remedy it with a timer relay inline with the SRR.

All the best,
Dan

Out of curiosity, what hardware e-stops solutions are you using, Daniel?

Sorry for the delay in getting back to you on this...

Here are some photos of the E-stop setup I use.

I have the "Reset Mach" soft button in MSM... this enables and disables the charge pump to the PMDX. I do not use this an an e-stop.
I have the physical button on the iMach3 pendant, this does the same thing.

The main machine button goes through a safety relay, which controls further relays... broadly does the following in one go:
- Enables the spindle drive.
- Enables the X/Y/Z axis drives.
- Interlocks the guard relay.
- Reports back to Mach3 so any hardware issues known trigger a software external e-stop.

Axis over travels or spindle motor overheating also trigger an e-stop condition.










Hope that helps.
All the best,
Dan