Is software Estop allowed

Tommy what you saying in your rant is wrong “software estop is not allowed “.   So, do yourself a favor and add an external estop to your 50 kg bench drill press and your 16-ton machine.I also hope you don’t let anyone else uses your software estop equipped machines, they are unsafe and you will not forgive yourself if someone else using them gets hurt.

And yes, no one asked me for advice but since Linuxcnc documentation does not address this subject I felt obligated to make hobbits and new Linuxcnc users aware of the use of Estop.

Tommy as Linuxcnc gate keeper do us (Linuxcnc users) favor and add a warning in the Linuxcnc documentation “software estop is not allowed.  here is no substitute for an external standalone Estop/reset”.

Gatekeeper ?
Full of good solid advice would be the better description.

Man you are so out of line with that comment.
Up til then it's been a decent discussion.

I'm just hoping there was a bit of confusion into the term "e-stop latch".

Just a little aside.
I've worked a lot of casual labour hire, disposable workers is what we really are, I was at a recycling plant, pulling steel that was missed during separation and wasn't supposed to go into the crusher. The plant wasn't the best safety wise. Anyways they had this dodgy estop setup, was like 2 step away from where you had to work. So after being there for a bit I realised the issue, spoke to the guy on site, no reaction, spoke to my contact at the labour hire mob, all they hid was ring the plant up and were assured yes there is an estop on the machine, tho access wasn't never discussed. So I said "Fuck it" and walked out. Got a call from from the labour hire mob, told them never to call again as their "safety officer was useless". Yeah and they are a major player in concrete recycling in Sydney.
So yeah machine safety is fucking important.
I fully agree a software estop is not the ideal way to go. Ah fuck I've lost my train of thought.

Are you using translation ?
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Benb wrote:

Tommy what you saying in your rant is wrong “software estop is not allowed “.

It is allowed, depends on machine, most hobby machines do not need it as the spindle is not controlled by LinuxCNC, etc etc etc
And my rant was about the "e-stop latch", not the "e-stop".

Benb wrote:

 So, do yourself a favor and add an external estop to your 50 kg bench drill press and your 16-ton machine.I also hope you don’t let anyone else uses your software estop equipped machines, they are unsafe and you will not forgive yourself if someone else using them gets hurt.

You missed the point, they do have E-stops, big ones at least two, and the proper safety stuff, always.
My small plasma machines do not have any, they do not need it, ever. My Big industrial plasma machines with DC servo motors have at least 2 e-stops and obligatory "extreme limits" on all axis
Never had a single incident on my machines, the biggest incident was braking an end mill.

Benb wrote:

And yes, no one asked me for advice but since Linuxcnc documentation does not address this subject I felt obligated to make hobbits and new Linuxcnc users aware of the use of Estop.

I already said thank you.

Benb wrote:

Tommy as Linuxcnc gate keeper do us (Linuxcnc users) favor and add a warning in the Linuxcnc documentation “software estop is not allowed.  here is no substitute for an external standalone Estop/reset”.

Again, as Aciera said above,

I don't have a problem with raising awareness about safety, there are a few post of mine on this forum where I have suggested safer procedures than what was being used. The statement I do not agree with is this one:

Linuxcnc ‘gate keepers’ should warn users that - software estops are not allowed - for safety sake.

It's enough of a struggle to try and keep the existing code base and its documentation even halfway updated with the volunteers we have. If you would like to add information about safety then I would invite you to add to the wiki:
wiki.linuxcnc.org/cgi-bin/wiki.pl

Hi guys. Since i've worked about this topic, i wanted to say something. First of all, Benb you are right. I also think software e-stop should be implemented in software side. I've integrated emergency stop button like yours to my machine some time. It was actually a circuit which cuts the power of motors, so when you pressed it the motor movements were being stopped but with a problem. The problem is that user was being able to open e-stop via gui(change the pins iocontrol.emc-enable-in and iocontrol.user-enable-out) while the emergency button is still pressed. And of course user was being able to move motors in software, without actual physical movement. I wanted to stop this action. As result, i've tried to add some logic in hal layer. But it didn't work as i want. The thing i really wanted was updating iocontrol.emc-enable-in and iocontrol.user-enable-out pins with extra control, which is emergency button is pressed or not. I've decided to examine the iocontrol component's source code because of this is the component which does the software e-stop. I've changed the source of iocontrol component in the way i described before, and it worked. I've left it as it is. The thing i did is:
1. Intervention to EMC_AUX_ESTOP_ON_TYPE and EMC_AUX_ESTOP_OFF_TYPE with checking extra pin which shows the button status. If button is pressed, iocontrol.emc-enable-in and iocontrol.user-enable-out are not gonna changed. If button is not pressed, it is okay to open e-stop in software.
2. Check the pin which shows emergency stop button is pressed in iocontrol's while loop, if it is pressed, update iocontrol.emc-enable-in and iocontrol.user-enable-out pins to do e-stop.

This solved my problem. User is no more able to change iocontrol.emc-enable-in and iocontrol.user-enable-out pins with a pressed emergency button and when the button is pressed, machine actually stops the movement and does e-stop.

This is my solution. I've changed the iocontrol component and integrated it in the way i described. The problem is that the way i check emergency stop button is pressed or not can be late. Because i am actually measuring the voltage which is given to motor drives. When it is lesser from some value, i am updating my hal pin as button is pressed. So the software receives the button status little bit late. But it is ok, if the button is pressed and there is no power, motors are not gonna be moved. I think it is safe.


I hope i didn't get your problem wrong. This is what i understand from the topic. If you guys have any questions, i can answer it in this context.

Thanks.

ok Benb, you are not from germany

We distinguish between emergency off and emergency stop.

Yes, you need a physical switch, but it can be handled by software. It even has to be in many cases, as a safe shutdown/braking of the machine must be ensured.

de.wikipedia.org/wiki/Notausschalter

in the english version are many more types:
en.wikipedia.org/wiki/Kill_switch