Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Gene Heskett]

On Saturday 10 August 2019 01:21:39 andrew beck wrote:

> Thanks for the advice Chris.
>
> I think what I'm actually asking is how to connect up the classic
> ladder stuff to make the gui e stop and the external big red button
> work together.
>
> So that way the machine goes into estop mode if the computer discovers
> a fault and also if I push the E stop in.  I want something like Sam's
> big machine.  But am stuck with a couple of simple things I think.  It
> would be so nice if someone made a quick video for that.
>
> I have classic ladder working now but am struggling with how to
> interface with the Hal layer.  I understand a bit about Hal now but
> have some gaps in my understanding which are holding me up
>
See "man iocontrol", and "man motion". There you will find the names of 
the hal "pins" you will need to "net" from the e-stop circuitry.
I would make a further recommendation that if axis drivers are disabled, 
I'd put a 50 millisecond delay in the driver disable signal path to give 
the rest of the machine time for motion to actively stop it, otherwise 
it could coast and do even more damage.

> Regards
>
> Andrew.
>
> On Sat, Aug 10, 2019, 5:00 PM Chris Albertson
> 
>
> wrote:
> > My opinion:   If the e-stop system is so complex that its design is
> > not simple and obvious then it is to complex to be safe.
> >
> > E-stop has to be so simple it is completely foolproof and design
> > such that if some part of it fails, like a wire comes loose then the
> > system stops. In other words, it needs to fail-safe.
> >
> > A good example is that all the "enable" pins on all the motor
> > controllers are held in the "enable" state by a power supply.  So
> > now if the supply fails or the wires connecting it fail the motors
> > all stop.  In other words the e-stop's job is to NOT stop the
> > machine but to enable it's operations
> >
> > Then when you press an e-stop button the button breaks a connection.
> >
> > If you are using complex logic the design is to complex to be 100%
> > safe. Ask youself, what would happen if part of the e-stop system
> > failed or was designed wrongly?  the answer has to be "all the
> > motors stop".
> >
> > On Fri, Aug 9, 2019 at 4:29 PM andrew beck
> > 
> >
> > wrote:
> > > Hi guys
> > >
> > > Just want to say thanks for the help with the e stop circuits. 
> > > All the replies were amazing
> > >
> > > I have all the relays working now but am stuck on classic ladder.
> > >
> > > I Don't actually know how to load it and do the most basic things
> > >
> > > Can someone show me how to start with the most basic things like
> > > actually opening the program please.  Or link me to any videos of
> > > the process
> > >
> > > Regards
> > >
> > > Andrew
> > >
> > > On Mon, Jul 22, 2019 at 12:30 PM Gregg Eshelman via Emc-users <
> > >
> > > emc-users@lists.sourceforge.net> wrote:
> > > > Emergency Stop buttons are made so that the knob locks in when
> > > > pushed
> >
> > and
> >
> > > > has to be rotated to unlock it so it can come out. Breakout
> > > > boards,
> >
> > VFDs,
> >
> > > > and various other machine control equipment often has E-Stop
> > > > inputs
> >
> > which
> >
> > > > can be wired in a circuit so one or more buttons can be used to
> > > > stop everything.
> > > >
> > > > The easiest way to setup an E-Stop circuit is to have everything
> > > > with
> >
> > an
> >
> > > > E-Stop connection require a voltage input, then wire them all in
> > > > series with one or more stop buttons. Hit any button, it opens
> > > > the circuit to everything. Needs no relays, no electronic
> > > > circuitry (outside of the breakout board etc), just dead simple
> > > > wire and lock open switch(es). You can add an enable switch to
> > > > the E-Stop circuit, with a relay that's held closed by the
> > > > E-Stop power. Then it's a 2 step process to
> >
> > re-enable
> >
> > > > the machine. Turn the E-Stop switch button to close it then
> > > > press the enable button to close its relay. That button will
> > > > also need pressed
> >
> > when
> >
> > > > starting the machine from powered off. It won't latch on if an
> > > > E-Stop button is still locked open.
> > > >
> > > > On Sunday, July 21, 2019, 5:12:08 AM MDT, andrew beck <
> > > > andrewbeck0...@gmail.com> wrote:
> > > >  I need to set up a latching relay somehow to make sure the E
> > > > stop
> > >
> > > doesn't
> > >
> > > > turn back on until I turn it on within linuxcnc.
> > > > ___
> > > > Emc-users mailing list
> > > > Emc-users@lists.sourceforge.net
> > > > https://lists.sourceforge.net/lists/listinfo/emc-users
> > >
> > > ___
> > > Emc-users mailing list
> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> > --
> >
> > Chris Albertson
> > Redondo Beach, California
> >
> > ___
> > Emc-users mailing list
> > 

Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Gene Heskett]

On Saturday 10 August 2019 00:57:29 Chris Albertson wrote:

> My opinion:   If the e-stop system is so complex that its design is
> not simple and obvious then it is to complex to be safe.
>
> E-stop has to be so simple it is completely foolproof and design such
> that if some part of it fails, like a wire comes loose then the system
> stops. In other words, it needs to fail-safe.
>
> A good example is that all the "enable" pins on all the motor
> controllers are held in the "enable" state by a power supply.  So now
> if the supply fails or the wires connecting it fail the motors all
> stop.  In other words the e-stop's job is to NOT stop the machine but
> to enable it's operations
>
> Then when you press an e-stop button the button breaks a connection.
>
> If you are using complex logic the design is to complex to be 100%
> safe. Ask youself, what would happen if part of the e-stop system
> failed or was designed wrongly?  the answer has to be "all the motors
> stop".

And one final point, since the e-stop is by definition unscheduled, the 
machine should be un-homed by that stop. Steppers in particular, will 
have no clue where they are when re-enabled next.  That you can/must do 
with a hal net statement, but the rest of the circuit should be hard 
wired. The little 7x10 lathes have a two pole switch that sells for 
about $15 from LMS, must be unlatched and opened to enable both 
contacts, in an emergency a fist brought down on top opens both contacts 
and mechanically latches it open. I can't think of a better yet cheap 
switch for that job.

> On Fri, Aug 9, 2019 at 4:29 PM andrew beck  
wrote:
> > Hi guys
> >
> > Just want to say thanks for the help with the e stop circuits.  All
> > the replies were amazing
> >
> > I have all the relays working now but am stuck on classic ladder.
> >
> > I Don't actually know how to load it and do the most basic things
> >
> > Can someone show me how to start with the most basic things like
> > actually opening the program please.  Or link me to any videos of
> > the process
> >
> > Regards
> >
> > Andrew
> >
> > On Mon, Jul 22, 2019 at 12:30 PM Gregg Eshelman via Emc-users <
> >
> > emc-users@lists.sourceforge.net> wrote:
> > > Emergency Stop buttons are made so that the knob locks in when
> > > pushed and has to be rotated to unlock it so it can come out.
> > > Breakout boards, VFDs, and various other machine control equipment
> > > often has E-Stop inputs which can be wired in a circuit so one or
> > > more buttons can be used to stop everything.
> > >
> > > The easiest way to setup an E-Stop circuit is to have everything
> > > with an E-Stop connection require a voltage input, then wire them
> > > all in series with one or more stop buttons. Hit any button, it
> > > opens the circuit to everything. Needs no relays, no electronic
> > > circuitry (outside of the breakout board etc), just dead simple
> > > wire and lock open switch(es). You can add an enable switch to the
> > > E-Stop circuit, with a relay that's held closed by the E-Stop
> > > power. Then it's a 2 step process to re-enable the machine. Turn
> > > the E-Stop switch button to close it then press the enable button
> > > to close its relay. That button will also need pressed when
> > > starting the machine from powered off. It won't latch on if an
> > > E-Stop button is still locked open.
> > >
> > > On Sunday, July 21, 2019, 5:12:08 AM MDT, andrew beck <
> > > andrewbeck0...@gmail.com> wrote:
> > >  I need to set up a latching relay somehow to make sure the E stop
> >
> > doesn't
> >
> > > turn back on until I turn it on within linuxcnc.
> > > ___
> > > Emc-users mailing list
> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users


Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[andrew beck]

Thanks for the advice Chris.

I think what I'm actually asking is how to connect up the classic ladder
stuff to make the gui e stop and the external big red button work together.

So that way the machine goes into estop mode if the computer discovers a
fault and also if I push the E stop in.  I want something like Sam's big
machine.  But am stuck with a couple of simple things I think.  It would be
so nice if someone made a quick video for that.

I have classic ladder working now but am struggling with how to interface
with the Hal layer.  I understand a bit about Hal now but have some gaps in
my understanding which are holding me up

Regards

Andrew.

On Sat, Aug 10, 2019, 5:00 PM Chris Albertson 
wrote:

> My opinion:   If the e-stop system is so complex that its design is not
> simple and obvious then it is to complex to be safe.
>
> E-stop has to be so simple it is completely foolproof and design such that
> if some part of it fails, like a wire comes loose then the system stops. In
> other words, it needs to fail-safe.
>
> A good example is that all the "enable" pins on all the motor controllers
> are held in the "enable" state by a power supply.  So now if the supply
> fails or the wires connecting it fail the motors all stop.  In other words
> the e-stop's job is to NOT stop the machine but to enable it's operations
>
> Then when you press an e-stop button the button breaks a connection.
>
> If you are using complex logic the design is to complex to be 100% safe.
> Ask youself, what would happen if part of the e-stop system failed or was
> designed wrongly?  the answer has to be "all the motors stop".
>
> On Fri, Aug 9, 2019 at 4:29 PM andrew beck 
> wrote:
>
> > Hi guys
> >
> > Just want to say thanks for the help with the e stop circuits.  All the
> > replies were amazing
> >
> > I have all the relays working now but am stuck on classic ladder.
> >
> > I Don't actually know how to load it and do the most basic things
> >
> > Can someone show me how to start with the most basic things like actually
> > opening the program please.  Or link me to any videos of the process
> >
> > Regards
> >
> > Andrew
> >
> > On Mon, Jul 22, 2019 at 12:30 PM Gregg Eshelman via Emc-users <
> > emc-users@lists.sourceforge.net> wrote:
> >
> > > Emergency Stop buttons are made so that the knob locks in when pushed
> and
> > > has to be rotated to unlock it so it can come out. Breakout boards,
> VFDs,
> > > and various other machine control equipment often has E-Stop inputs
> which
> > > can be wired in a circuit so one or more buttons can be used to stop
> > > everything.
> > >
> > > The easiest way to setup an E-Stop circuit is to have everything with
> an
> > > E-Stop connection require a voltage input, then wire them all in series
> > > with one or more stop buttons. Hit any button, it opens the circuit to
> > > everything. Needs no relays, no electronic circuitry (outside of the
> > > breakout board etc), just dead simple wire and lock open switch(es).
> > > You can add an enable switch to the E-Stop circuit, with a relay that's
> > > held closed by the E-Stop power. Then it's a 2 step process to
> re-enable
> > > the machine. Turn the E-Stop switch button to close it then press the
> > > enable button to close its relay. That button will also need pressed
> when
> > > starting the machine from powered off. It won't latch on if an E-Stop
> > > button is still locked open.
> > >
> > > On Sunday, July 21, 2019, 5:12:08 AM MDT, andrew beck <
> > > andrewbeck0...@gmail.com> wrote:
> > >  I need to set up a latching relay somehow to make sure the E stop
> > doesn't
> > > turn back on until I turn it on within linuxcnc.
> > > ___
> > > Emc-users mailing list
> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> > >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
>
>
> --
>
> Chris Albertson
> Redondo Beach, California
>
> ___
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> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

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Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Chris Albertson]

My opinion:   If the e-stop system is so complex that its design is not
simple and obvious then it is to complex to be safe.

E-stop has to be so simple it is completely foolproof and design such that
if some part of it fails, like a wire comes loose then the system stops. In
other words, it needs to fail-safe.

A good example is that all the "enable" pins on all the motor controllers
are held in the "enable" state by a power supply.  So now if the supply
fails or the wires connecting it fail the motors all stop.  In other words
the e-stop's job is to NOT stop the machine but to enable it's operations

Then when you press an e-stop button the button breaks a connection.

If you are using complex logic the design is to complex to be 100% safe.
Ask youself, what would happen if part of the e-stop system failed or was
designed wrongly?  the answer has to be "all the motors stop".

On Fri, Aug 9, 2019 at 4:29 PM andrew beck  wrote:

> Hi guys
>
> Just want to say thanks for the help with the e stop circuits.  All the
> replies were amazing
>
> I have all the relays working now but am stuck on classic ladder.
>
> I Don't actually know how to load it and do the most basic things
>
> Can someone show me how to start with the most basic things like actually
> opening the program please.  Or link me to any videos of the process
>
> Regards
>
> Andrew
>
> On Mon, Jul 22, 2019 at 12:30 PM Gregg Eshelman via Emc-users <
> emc-users@lists.sourceforge.net> wrote:
>
> > Emergency Stop buttons are made so that the knob locks in when pushed and
> > has to be rotated to unlock it so it can come out. Breakout boards, VFDs,
> > and various other machine control equipment often has E-Stop inputs which
> > can be wired in a circuit so one or more buttons can be used to stop
> > everything.
> >
> > The easiest way to setup an E-Stop circuit is to have everything with an
> > E-Stop connection require a voltage input, then wire them all in series
> > with one or more stop buttons. Hit any button, it opens the circuit to
> > everything. Needs no relays, no electronic circuitry (outside of the
> > breakout board etc), just dead simple wire and lock open switch(es).
> > You can add an enable switch to the E-Stop circuit, with a relay that's
> > held closed by the E-Stop power. Then it's a 2 step process to re-enable
> > the machine. Turn the E-Stop switch button to close it then press the
> > enable button to close its relay. That button will also need pressed when
> > starting the machine from powered off. It won't latch on if an E-Stop
> > button is still locked open.
> >
> > On Sunday, July 21, 2019, 5:12:08 AM MDT, andrew beck <
> > andrewbeck0...@gmail.com> wrote:
> >  I need to set up a latching relay somehow to make sure the E stop
> doesn't
> > turn back on until I turn it on within linuxcnc.
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>


-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[TJoseph Powderly]

hello
i got too many hits with google "linuxcnc classicladder"
try ti out, theres docs, beginner tutorial, demos videos discussions
hth
tomp

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Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[andrew beck]

Hi guys

Just want to say thanks for the help with the e stop circuits.  All the
replies were amazing

I have all the relays working now but am stuck on classic ladder.

I Don't actually know how to load it and do the most basic things

Can someone show me how to start with the most basic things like actually
opening the program please.  Or link me to any videos of the process

Regards

Andrew

On Mon, Jul 22, 2019 at 12:30 PM Gregg Eshelman via Emc-users <
emc-users@lists.sourceforge.net> wrote:

> Emergency Stop buttons are made so that the knob locks in when pushed and
> has to be rotated to unlock it so it can come out. Breakout boards, VFDs,
> and various other machine control equipment often has E-Stop inputs which
> can be wired in a circuit so one or more buttons can be used to stop
> everything.
>
> The easiest way to setup an E-Stop circuit is to have everything with an
> E-Stop connection require a voltage input, then wire them all in series
> with one or more stop buttons. Hit any button, it opens the circuit to
> everything. Needs no relays, no electronic circuitry (outside of the
> breakout board etc), just dead simple wire and lock open switch(es).
> You can add an enable switch to the E-Stop circuit, with a relay that's
> held closed by the E-Stop power. Then it's a 2 step process to re-enable
> the machine. Turn the E-Stop switch button to close it then press the
> enable button to close its relay. That button will also need pressed when
> starting the machine from powered off. It won't latch on if an E-Stop
> button is still locked open.
>
> On Sunday, July 21, 2019, 5:12:08 AM MDT, andrew beck <
> andrewbeck0...@gmail.com> wrote:
>  I need to set up a latching relay somehow to make sure the E stop doesn't
> turn back on until I turn it on within linuxcnc.
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

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Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Gregg Eshelman via Emc-users]

Emergency Stop buttons are made so that the knob locks in when pushed and has 
to be rotated to unlock it so it can come out. Breakout boards, VFDs, and 
various other machine control equipment often has E-Stop inputs which can be 
wired in a circuit so one or more buttons can be used to stop everything.

The easiest way to setup an E-Stop circuit is to have everything with an E-Stop 
connection require a voltage input, then wire them all in series with one or 
more stop buttons. Hit any button, it opens the circuit to everything. Needs no 
relays, no electronic circuitry (outside of the breakout board etc), just dead 
simple wire and lock open switch(es).
You can add an enable switch to the E-Stop circuit, with a relay that's held 
closed by the E-Stop power. Then it's a 2 step process to re-enable the 
machine. Turn the E-Stop switch button to close it then press the enable button 
to close its relay. That button will also need pressed when starting the 
machine from powered off. It won't latch on if an E-Stop button is still locked 
open.

On Sunday, July 21, 2019, 5:12:08 AM MDT, andrew beck 
 wrote:  
 I need to set up a latching relay somehow to make sure the E stop doesn't
turn back on until I turn it on within linuxcnc.  
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Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[andy pugh]

On Sun, 21 Jul 2019 at 20:33, Gene Heskett  wrote:

>
> Same here Andy. Tends to keep me alert, but we both know that is not a
> guarantee.


At least someone would notice you were missing. I reckon it would be about
a week before my work colleagues began to wonder if it wasn't just a
holiday I had forgotten to mention.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is designed
for the especial use of mechanical geniuses, daredevils and lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916

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Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Gene Heskett]

On Sunday 21 July 2019 13:40:53 andy pugh wrote:

> On both my machines I took the decision to rely on LinuxCNC to handle
> the latching, but to have the E-Stop button directly cut power to the
> drives. This might not be the best system to use for 100% coverage of
> software failure modes, but these are hobby machines. [1]
> So, LinuxCNC closes the contactor that feeds the servo PSU and the
> VFD. The wiring for the control solenoid of that contactor loops
> around the machine to the single e-stop on the lathe and both those on
> the mill. In the case of the mill the switches have a second NO
> contact block that signals to LinuxCNC that the e-stop has been
> pressed, and that toggles the software e-stop in LinuxCNC through HAL.
>  The lathe uses
> halui.estop.activate wheres the mill uses iocontrol.0.emc-enable-in.
> On reflection it would probably be better to use a realtime pin from
> the motion module, in theory both iocontrol and halui are susceptible
> to user-space lock ups. But then if that has happened then, whilst
> motion is likely to still be running fine, the signals to the rest of
> the system from there are not guaranteed anyway.
>
> On the lathe, rather than use a second contact on the e-stop switch
> itself I use an auxiliary contact on the contactor to signal the
> e-stop state. I confess I have forgotten how I did it, whether HAL
> logic detects the contactor being powered but the auxilliary contact
> being open, or whether it is an NC contact that supplies 24V to the IO
> input from the solenoid control voltage if the solenoid is powered but
> NC contact has remained closed.
>
>
> [1] Arguably this means that they should be built to an even higher
> standard. If I get tangled in my machines _nobody_ is coming to help.

Same here Andy. Tends to keep me alert, but we both know that is not a 
guarantee.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Gene Heskett]

On Sunday 21 July 2019 12:57:18 Sam Sokolik wrote:

> sorry - It is actually this video
>
NP Sam, I enjoyed the tour. Quite a machine.
> https://www.youtube.com/watch?v=XSojs1pUSlg
>
> On Sun, Jul 21, 2019 at 11:48 AM Sam Sokolik  
wrote:
> > I should say - we normally have the estop loop enables power to the
> > drives, hydraulics and vfd.  Then the power button is what actually
> > enables the drives so linuxcnc is in control.
> >
> > (I am skunkworks - my name is sam and not chris ;) ) Chris is a
> > developer for linuxcnc...
> >
> > This video sort of explains/shows the estop..
> >
> > https://www.youtube.com/watch?v=fTI_Ypv4FQE
> >
> > On Sun, Jul 21, 2019 at 11:37 AM Sam Sokolik  
wrote:
> >> I use estop type 4...
> >>
> >> http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Sample_HAL_And_ClassicLadd
> >>er
> >>
> >> These examples use classic ladder - although I think there is a hal
> >> component that does something similar
> >>
> >> http://linuxcnc.org/docs/2.7/html/man/man9/estop_latch.9.html
> >>
> >> On Sun, Jul 21, 2019 at 7:35 AM Gene Heskett 
> >>
> >> wrote:
> >>> On Sunday 21 July 2019 07:08:52 andrew beck wrote:
> >>> > Hi guys
> >>> >
> >>> > I have got my cnc mill control panel working ok now just have
> >>> > some questions about the best and proper way to implement the
> >>> > safety E stop circuit and initial power on of the cnc machine
> >>> >
> >>> > I did some searching of course, but thought I would ask here and
> >>> > see what the latest and best way is.  searching on the forum,
> >>> > some of the info was a little dated.  so if anyone has any
> >>> > advice I would most appreciate it.  I saw on Youtube what
> >>> > samco(skunkworks)  (I think his name is chris Radek) has done. 
> >>> > And this is pretty much what I want i think.
> >>> >
> >>> > I think this should happen when the E stop is pushed.
> >>> >
> >>> > Cut control power to all servos and main spindle VFD.
> >>>
> >>> I am probably a poor one to advise since I have not a separate
> >>> E-Stop on any of my machines, depending on the f1 and f2 keys to
> >>> do it all, which also still leaves me subject who owns the
> >>> keyboard focus.
> >>>
> >>> >  (I think I may need to just send a E stop signal to the VFD as
> >>> > it doesn't have control power that I can cut.)  It seems a big
> >>> > extreme to cut main power and possible damage the vfd with loose
> >>> > high voltages etc.
> >>>
> >>> I use the F1 key to enable power and this includes the vfd by way
> >>> of the usual 40 amp 400 volt SSR's which are easily controlled.
> >>> The F2 key enables motion.
> >>>
> >>> In this way you have an onscreen tally as the the machines state.
> >>>
> >>> > It should tell linuxcnc that the E stop is pushed.
> >>> > I need to set up a latching relay somehow to make sure the E
> >>> > stop doesn't turn back on until I turn it on within linuxcnc.
> >>> >
> >>> > Servo Power on setup.
> >>> >
> >>> > I want a Button I can push which enables all the servo drives(
> >>> > there is a Servo on pin on the servo drives)
> >>>
> >>> This can be done in the .hal file by enableing the servo drives
> >>> from the status of the F1 key latch.
> >>>
> >>> > and then also enable the vfd
> >>>
> >>> Same here, fire the SSR's from the same signal.
> >>>
> >>> > however I need to do that.  This is separate to the E stop. 
> >>> > Currently I am only using step and direction control and I am
> >>> > wondering how hard it will be to tie in the encoder signals to
> >>> > linux cnc with another mesa card.  otherwise when i push the E
> >>> > stop I will have to re home the machine.
> >>>
> >>> I have not tried to do that, you will have lost your home if the
> >>> power is
> >>> cut. I use steppers and with the drivers still enabled by F1, the
> >>> stop distance is rarely more than 1 count at working speed. But
> >>> can if in a rapid move at the time of the stop take several steps
> >>> which the feeback encoder will miss, so you should rehome. 
> >>> Servo's are another story, and should return to the null point
> >>> when re-enabled.
> >>>
> >>> Here, I consider the F2 key as an E-stop as it stops motion as
> >>> fast as it
> >>> can, while leaving power on everything.
> >>> Leaving power on the servo's, it seems to me would give a faster
> >>> stop than killing power with its slow decay to zero.
> >>>
> >>> I don't think it would be too hard to rig a big red button to be
> >>> the equ of pressing the F2 key. I made progress on getting more
> >>> spare inputs, and am considering something like a doorbell button
> >>> I can slap. But I can't find such a button without a light bulb
> >>> across the contacts. You would have to cut the light bulb out and
> >>> remove it, otherwise the switch is closed forever to a bob input
> >>> pin.  One could supply that pin with enough pullup power to light
> >>> the bulb, but most doorbell are 24 volt circuits, so an si diode
> >>> would be needed to protect the bob's input.
> >>>
> >>> So I'm not "kosher" but unless lcnc 

Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Gene Heskett]

On Sunday 21 July 2019 12:37:37 Sam Sokolik wrote:

> I use estop type 4...
>
> http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Sample_HAL_And_ClassicLadder
>
> These examples use classic ladder - although I think there is a hal
> component that does something similar
>
> http://linuxcnc.org/docs/2.7/html/man/man9/estop_latch.9.html
>
Many thanks for bailing me out by furnishing these links, Sam. In fact if 
I set mine up for a big red button kill, I will likely use type 4 
myself. I had a chance several years back to grab the big red and yellow 
assembly used as the power switch on the 7x12's many years ago, so I 
still have them in a drawer.  These are double breakers so are just as 
usefull in a logic circuit as in a 240 volt line switch. And now that I 
have enough i/o even on TLM. only this 95+F weather is holding me back.

I'm alternately hibernating in the AC, and keeping house includeing 
careing for my missus, and haunting this keyboard. Hoping for cooler 
weather. But despite Trumps denials, global warming is real, and its 
worse than projected. Here in WV for 35 years, its close to 15F warmer 
year round now than in 84 when I come here.

> On Sun, Jul 21, 2019 at 7:35 AM Gene Heskett  
wrote:
> > On Sunday 21 July 2019 07:08:52 andrew beck wrote:
> > > Hi guys
> > >
> > > I have got my cnc mill control panel working ok now just have some
> > > questions about the best and proper way to implement the safety E
> > > stop circuit and initial power on of the cnc machine
> > >
> > > I did some searching of course, but thought I would ask here and
> > > see what the latest and best way is.  searching on the forum, some
> > > of the info was a little dated.  so if anyone has any advice I
> > > would most appreciate it.  I saw on Youtube what samco(skunkworks)
> > >  (I think his name is chris Radek) has done.  And this is pretty
> > > much what I want i think.
> > >
> > > I think this should happen when the E stop is pushed.
> > >
> > > Cut control power to all servos and main spindle VFD.
> >
> > I am probably a poor one to advise since I have not a separate
> > E-Stop on any of my machines, depending on the f1 and f2 keys to do
> > it all, which also still leaves me subject who owns the keyboard
> > focus.
> >
> > >  (I think I may need to just send a E stop signal to the VFD as it
> > > doesn't have control power that I can cut.)  It seems a big
> > > extreme to cut main power and possible damage the vfd with loose
> > > high voltages etc.
> >
> > I use the F1 key to enable power and this includes the vfd by way of
> > the usual 40 amp 400 volt SSR's which are easily controlled. The F2
> > key enables motion.
> >
> > In this way you have an onscreen tally as the the machines state.
> >
> > > It should tell linuxcnc that the E stop is pushed.
> > > I need to set up a latching relay somehow to make sure the E stop
> > > doesn't turn back on until I turn it on within linuxcnc.
> > >
> > > Servo Power on setup.
> > >
> > > I want a Button I can push which enables all the servo drives(
> > > there is a Servo on pin on the servo drives)
> >
> > This can be done in the .hal file by enableing the servo drives from
> > the status of the F1 key latch.
> >
> > > and then also enable the vfd
> >
> > Same here, fire the SSR's from the same signal.
> >
> > > however I need to do that.  This is separate to the E stop. 
> > > Currently I am only using step and direction control and I am
> > > wondering how hard it will be to tie in the encoder signals to
> > > linux cnc with another mesa card.  otherwise when i push the E
> > > stop I will have to re home the machine.
> >
> > I have not tried to do that, you will have lost your home if the
> > power is cut. I use steppers and with the drivers still enabled by
> > F1, the stop distance is rarely more than 1 count at working speed.
> > But can if in a rapid move at the time of the stop take several
> > steps which the feeback encoder will miss, so you should rehome. 
> > Servo's are another story, and should return to the null point when
> > re-enabled.
> >
> > Here, I consider the F2 key as an E-stop as it stops motion as fast
> > as it can, while leaving power on everything.
> > Leaving power on the servo's, it seems to me would give a faster
> > stop than killing power with its slow decay to zero.
> >
> > I don't think it would be too hard to rig a big red button to be the
> > equ of pressing the F2 key. I made progress on getting more spare
> > inputs, and am considering something like a doorbell button I can
> > slap. But I can't find such a button without a light bulb across the
> > contacts. You would have to cut the light bulb out and remove it,
> > otherwise the switch is closed forever to a bob input pin.  One
> > could supply that pin with enough pullup power to light the bulb,
> > but most doorbell are 24 volt circuits, so an si diode would be
> > needed to protect the bob's input.
> >
> > So I'm not "kosher" but unless lcnc doesn't have keyboard focus, it
> > 

Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[andy pugh]

On both my machines I took the decision to rely on LinuxCNC to handle the
latching, but to have the E-Stop button directly cut power to the drives.
This might not be the best system to use for 100% coverage of software
failure modes, but these are hobby machines. [1]
So, LinuxCNC closes the contactor that feeds the servo PSU and the VFD. The
wiring for the control solenoid of that contactor loops around the machine
to the single e-stop on the lathe and both those on the mill.
In the case of the mill the switches have a second NO contact block that
signals to LinuxCNC that the e-stop has been pressed, and that toggles the
software e-stop in LinuxCNC through HAL.  The lathe uses
halui.estop.activate wheres the mill uses iocontrol.0.emc-enable-in.
On reflection it would probably be better to use a realtime pin from the
motion module, in theory both iocontrol and halui are susceptible to
user-space lock ups. But then if that has happened then, whilst motion is
likely to still be running fine, the signals to the rest of the system from
there are not guaranteed anyway.

On the lathe, rather than use a second contact on the e-stop switch itself
I use an auxiliary contact on the contactor to signal the e-stop state. I
confess I have forgotten how I did it, whether HAL logic detects the
contactor being powered but the auxilliary contact being open, or whether
it is an NC contact that supplies 24V to the IO input from the solenoid
control voltage if the solenoid is powered but NC contact has remained
closed.


[1] Arguably this means that they should be built to an even higher
standard. If I get tangled in my machines _nobody_ is coming to help.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is designed
for the especial use of mechanical geniuses, daredevils and lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916

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Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Chris Albertson]

I think there are two levels of "Stop".One can be implemented in
software and might be a function key (rather unreliable) or simple
mechanical button that is monitored by hal.These solutions work if
the software works.  But if there is a serious bug in EMC or your
configuration this solution fails

The most reliable thing is to buy one of those big 2" diameter estop
buttons that have a mechanical latch that you trist to release.   This is a
big button that you hit with a fist to activate.   The best setup is if the
e-stop button supplies power to keep relay contacts closed.   SO if the
power is cut (by slamming your fist on the button) then power is cut to the
motors. Be sure to handle back EMI with diodes across the reply.   You
need to use the "normal closed" contacts in the switch so that if some
connector comes to lose the machine stops.  Failures in connections
should always half the machine.Do NOT use a latching relay.   You want
the machine to stop when the power to the relay stops

The question is what kind of problem you are addressing?   Are you trying
to solve the problem of when a g-code file has a bad number in it?Or
when there is a serious software bug or a serious hardware failure.   If
the later then the e-stop system has to be 100% independent of the computer
controller.

Of course, you can always simply connect everything, the computer, and the
motors to the same AC power switch.  If there is a problem with back
EMF, address that.

On Sun, Jul 21, 2019 at 4:11 AM andrew beck 
wrote:

> Hi guys
>
> I have got my cnc mill control panel working ok now just have some
> questions about the best and proper way to implement the safety E stop
> circuit and initial power on of the cnc machine
>
> I did some searching of course, but thought I would ask here and see what
> the latest and best way is.  searching on the forum, some of the info was a
> little dated.  so if anyone has any advice I would most appreciate it.  I
> saw on Youtube what samco(skunkworks)  (I think his name is chris Radek)
> has done.  And this is pretty much what I want i think.
>
> I think this should happen when the E stop is pushed.
>
> Cut control power to all servos and main spindle VFD.
>  (I think I may need to just send a E stop signal to the VFD as it doesn't
> have control power that I can cut.)  It seems a big extreme to cut main
> power and possible damage the vfd with loose high voltages etc.
>
> It should tell linuxcnc that the E stop is pushed.
> I need to set up a latching relay somehow to make sure the E stop doesn't
> turn back on until I turn it on within linuxcnc.
>
> Servo Power on setup.
>
> I want a Button I can push which enables all the servo drives( there is a
> Servo on pin on the servo drives)   and then also enable the vfd however I
> need to do that.  This is separate to the E stop.  Currently I am only
> using step and direction control and I am wondering how hard it will be to
> tie in the encoder signals to linux cnc with another mesa card.  otherwise
> when i push the E stop I will have to re home the machine.  anyway please
> sing out with any feedback you have and ideas.  I would love to get some
> ideas here from those who have done this all before.
>
> I am using a mesa 5i25 7i76 combo.
>
> And I have all sorts of contactors etc.
>
> Regards
>
> Andrew
>
> <
> https://www.avast.com/sig-email?utm_medium=email_source=link_campaign=sig-email_content=webmail
> >
> Virus-free.
> www.avast.com
> <
> https://www.avast.com/sig-email?utm_medium=email_source=link_campaign=sig-email_content=webmail
> >
> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
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-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Sam Sokolik]

sorry - It is actually this video

https://www.youtube.com/watch?v=XSojs1pUSlg


On Sun, Jul 21, 2019 at 11:48 AM Sam Sokolik  wrote:

> I should say - we normally have the estop loop enables power to the
> drives, hydraulics and vfd.  Then the power button is what actually enables
> the drives so linuxcnc is in control.
>
> (I am skunkworks - my name is sam and not chris ;) ) Chris is a developer
> for linuxcnc...
>
> This video sort of explains/shows the estop..
>
> https://www.youtube.com/watch?v=fTI_Ypv4FQE
>
> On Sun, Jul 21, 2019 at 11:37 AM Sam Sokolik  wrote:
>
>> I use estop type 4...
>>
>> http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Sample_HAL_And_ClassicLadder
>>
>> These examples use classic ladder - although I think there is a hal
>> component that does something similar
>>
>> http://linuxcnc.org/docs/2.7/html/man/man9/estop_latch.9.html
>>
>> On Sun, Jul 21, 2019 at 7:35 AM Gene Heskett 
>> wrote:
>>
>>> On Sunday 21 July 2019 07:08:52 andrew beck wrote:
>>>
>>> > Hi guys
>>> >
>>> > I have got my cnc mill control panel working ok now just have some
>>> > questions about the best and proper way to implement the safety E stop
>>> > circuit and initial power on of the cnc machine
>>> >
>>> > I did some searching of course, but thought I would ask here and see
>>> > what the latest and best way is.  searching on the forum, some of the
>>> > info was a little dated.  so if anyone has any advice I would most
>>> > appreciate it.  I saw on Youtube what samco(skunkworks)  (I think his
>>> > name is chris Radek) has done.  And this is pretty much what I want i
>>> > think.
>>> >
>>> > I think this should happen when the E stop is pushed.
>>> >
>>> > Cut control power to all servos and main spindle VFD.
>>>
>>> I am probably a poor one to advise since I have not a separate E-Stop
>>> on any of my machines, depending on the f1 and f2 keys to do it all,
>>> which also still leaves me subject who owns the keyboard focus.
>>>
>>> >  (I think I may need to just send a E stop signal to the VFD as it
>>> > doesn't have control power that I can cut.)  It seems a big extreme to
>>> > cut main power and possible damage the vfd with loose high voltages
>>> > etc.
>>>
>>> I use the F1 key to enable power and this includes the vfd by way of the
>>> usual 40 amp 400 volt SSR's which are easily controlled. The F2 key
>>> enables motion.
>>>
>>> In this way you have an onscreen tally as the the machines state.
>>>
>>> > It should tell linuxcnc that the E stop is pushed.
>>> > I need to set up a latching relay somehow to make sure the E stop
>>> > doesn't turn back on until I turn it on within linuxcnc.
>>> >
>>> > Servo Power on setup.
>>> >
>>> > I want a Button I can push which enables all the servo drives( there
>>> > is a Servo on pin on the servo drives)
>>> This can be done in the .hal file by enableing the servo drives from the
>>> status of the F1 key latch.
>>> > and then also enable the vfd
>>> Same here, fire the SSR's from the same signal.
>>> >
>>> > however I need to do that.  This is separate to the E stop.  Currently
>>> > I am only using step and direction control and I am wondering how hard
>>> > it will be to tie in the encoder signals to linux cnc with another
>>> > mesa card.  otherwise when i push the E stop I will have to re home
>>> > the machine.
>>>
>>> I have not tried to do that, you will have lost your home if the power
>>> is
>>> cut. I use steppers and with the drivers still enabled by F1, the stop
>>> distance is rarely more than 1 count at working speed. But can if in a
>>> rapid move at the time of the stop take several steps which the feeback
>>> encoder will miss, so you should rehome.  Servo's are another story, and
>>> should return to the null point when re-enabled.
>>>
>>> Here, I consider the F2 key as an E-stop as it stops motion as fast as
>>> it
>>> can, while leaving power on everything.
>>> Leaving power on the servo's, it seems to me would give a faster stop
>>> than killing power with its slow decay to zero.
>>>
>>> I don't think it would be too hard to rig a big red button to be the equ
>>> of pressing the F2 key. I made progress on getting more spare inputs,
>>> and am considering something like a doorbell button I can slap. But I
>>> can't find such a button without a light bulb across the contacts. You
>>> would have to cut the light bulb out and remove it, otherwise the switch
>>> is closed forever to a bob input pin.  One could supply that pin with
>>> enough pullup power to light the bulb, but most doorbell are 24 volt
>>> circuits, so an si diode would be needed to protect the bob's input.
>>>
>>> So I'm not "kosher" but unless lcnc doesn't have keyboard focus, it
>>> works
>>> for me, and the diffs are minimal. I'd have a bigger problem figuring
>>> out where to put the switch so its in a consistent location so muscle
>>> memory could be depended on once you got used to it.
>>>
>>> Believe me, there is nothing more frustrating that recognizing the sound
>>> of a 

Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Sam Sokolik]

I should say - we normally have the estop loop enables power to the drives,
hydraulics and vfd.  Then the power button is what actually enables the
drives so linuxcnc is in control.

(I am skunkworks - my name is sam and not chris ;) ) Chris is a developer
for linuxcnc...

This video sort of explains/shows the estop..

https://www.youtube.com/watch?v=fTI_Ypv4FQE

On Sun, Jul 21, 2019 at 11:37 AM Sam Sokolik  wrote:

> I use estop type 4...
>
> http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Sample_HAL_And_ClassicLadder
>
> These examples use classic ladder - although I think there is a hal
> component that does something similar
>
> http://linuxcnc.org/docs/2.7/html/man/man9/estop_latch.9.html
>
> On Sun, Jul 21, 2019 at 7:35 AM Gene Heskett  wrote:
>
>> On Sunday 21 July 2019 07:08:52 andrew beck wrote:
>>
>> > Hi guys
>> >
>> > I have got my cnc mill control panel working ok now just have some
>> > questions about the best and proper way to implement the safety E stop
>> > circuit and initial power on of the cnc machine
>> >
>> > I did some searching of course, but thought I would ask here and see
>> > what the latest and best way is.  searching on the forum, some of the
>> > info was a little dated.  so if anyone has any advice I would most
>> > appreciate it.  I saw on Youtube what samco(skunkworks)  (I think his
>> > name is chris Radek) has done.  And this is pretty much what I want i
>> > think.
>> >
>> > I think this should happen when the E stop is pushed.
>> >
>> > Cut control power to all servos and main spindle VFD.
>>
>> I am probably a poor one to advise since I have not a separate E-Stop
>> on any of my machines, depending on the f1 and f2 keys to do it all,
>> which also still leaves me subject who owns the keyboard focus.
>>
>> >  (I think I may need to just send a E stop signal to the VFD as it
>> > doesn't have control power that I can cut.)  It seems a big extreme to
>> > cut main power and possible damage the vfd with loose high voltages
>> > etc.
>>
>> I use the F1 key to enable power and this includes the vfd by way of the
>> usual 40 amp 400 volt SSR's which are easily controlled. The F2 key
>> enables motion.
>>
>> In this way you have an onscreen tally as the the machines state.
>>
>> > It should tell linuxcnc that the E stop is pushed.
>> > I need to set up a latching relay somehow to make sure the E stop
>> > doesn't turn back on until I turn it on within linuxcnc.
>> >
>> > Servo Power on setup.
>> >
>> > I want a Button I can push which enables all the servo drives( there
>> > is a Servo on pin on the servo drives)
>> This can be done in the .hal file by enableing the servo drives from the
>> status of the F1 key latch.
>> > and then also enable the vfd
>> Same here, fire the SSR's from the same signal.
>> >
>> > however I need to do that.  This is separate to the E stop.  Currently
>> > I am only using step and direction control and I am wondering how hard
>> > it will be to tie in the encoder signals to linux cnc with another
>> > mesa card.  otherwise when i push the E stop I will have to re home
>> > the machine.
>>
>> I have not tried to do that, you will have lost your home if the power is
>> cut. I use steppers and with the drivers still enabled by F1, the stop
>> distance is rarely more than 1 count at working speed. But can if in a
>> rapid move at the time of the stop take several steps which the feeback
>> encoder will miss, so you should rehome.  Servo's are another story, and
>> should return to the null point when re-enabled.
>>
>> Here, I consider the F2 key as an E-stop as it stops motion as fast as it
>> can, while leaving power on everything.
>> Leaving power on the servo's, it seems to me would give a faster stop
>> than killing power with its slow decay to zero.
>>
>> I don't think it would be too hard to rig a big red button to be the equ
>> of pressing the F2 key. I made progress on getting more spare inputs,
>> and am considering something like a doorbell button I can slap. But I
>> can't find such a button without a light bulb across the contacts. You
>> would have to cut the light bulb out and remove it, otherwise the switch
>> is closed forever to a bob input pin.  One could supply that pin with
>> enough pullup power to light the bulb, but most doorbell are 24 volt
>> circuits, so an si diode would be needed to protect the bob's input.
>>
>> So I'm not "kosher" but unless lcnc doesn't have keyboard focus, it works
>> for me, and the diffs are minimal. I'd have a bigger problem figuring
>> out where to put the switch so its in a consistent location so muscle
>> memory could be depended on once you got used to it.
>>
>> Believe me, there is nothing more frustrating that recognizing the sound
>> of a 15 hp water pump thats suddenly single phased, and your hand is
>> headed to the off button, but is still 18" from it when the lights go
>> out because the 1200 amp/phase building breaker has tripped like a 12
>> gauge, followed a few  milliseconds later by the 

Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[John Dammeyer]

Hi Andrew,
I'm top posting because I'm not really responding to anything specific that 
you've said.  Only on how I've done it.

First the machine, one similar to a Grizzly G3616, has a locking RED ESTOP 
button, a SPINDLE ON button, SPINDLE FWD/REV and a COOLANT PUMP ON switch.  
There's also a 110VAC circuit for power feed and I tapped onto that for the DRO.
 
It's all relay logic inside the control panel and wired in such a way that if 
the ESTOP is hit while the SPINLDE and/or COOLANT PUMP are ON then power is 
removed from both and the 4PDT relay running power to them,  controlled by the 
ESTOP NC contact,  is now released.  One of the four poles of that relay was 
wired so that if the ESTOP is released nothing starts up again.  All DPDT 
controlled systems that were in the relay enable circuit have to be switched 
off again before the ESTOP circuit allows power to this master relay.  The 
110VAC circuit to the DRO and power feed are also controlled by the 4PDT relay. 
 

So the scenario is, you hit ESTOP, machine stops!  You untwist and unlatch the 
ESTOP and nothing happens even though you forgot to turn the SPINDLE switch 
off.  Once you switch the SPINDLE switch back to centre OFF, power comes back 
on. 

So I added a relay and luckily the ESTOP switch had a second unused NC contact. 
   Two pairs of wires come out of the control box to the CNC system.  One of 
them is the ESTOP NC circuit.  They have to be connected so they can be wired 
through a second ESTOP button and also a relay controlled by the PC.  Now, hit 
either the ESTOP, or have the PC open a relay controlled by the CNC software 
ESTOP circuit and again it's like you've pressed the ESTOP button on the 
machine.  Everything stops.

The second output pair of wires are to the contacts of the extra relay I 
installed.  At the moment they control the 220VAC Current Limit power relay to 
the CNC motor transformers.  So a limit switch or some other CNC based ESTOP 
condition removes AC power to the Servo and Stepper Motor power supplies.  The 
AC to the PC and the Breakout Board are not shut off nor is the 24V instrument 
bus.

Here's the only down side so far.  The filter capacitors on the big 105VDC 
Servo supply do have a crowbar over voltage circuit to prevent the back EMF 
from a decelerating motor exceeding a high voltage set point.  (about 115VDC)  
This protects the Servo Drives.  This same crowbar circuit is automatically 
switched ON when AC power is removed so a few seconds after AC is gone the DC 
has been bled off the caps.  No remnant of high voltage remains for safety.  
But that does take a few seconds.

The HP_UHU servo drives and the STMBL on the Rotary A axis all have their 
ENABLE controlled by the ESTOP circuit so motion control stops.  Bu t it does 
take a few seconds for the DC power to vanish.

However, the stepping pulses to the motors has been stopped by the ESTOP 
condition.  The motors continue to turn but without stepping pulses input and 
so even if the driver isn't put into a disable condition, the encoder pulses 
returned to the driver no longer match and a following error occurs and the 
driver goes into a following error condition.  

I have my limit switches set a little bit away from the hard mechanical stops 
so as the motor coasts to a stop the leadscrew so the table runs into the 
mechanical stop but not really hard.  Once power is back and the limit switch 
is overridden the system has enough power to move off the switch.  But the 
higher the speed the further it coasts.  Haven't figured out how to deal with 
that yet without giving up more motion at the far end.

I've included the latest drawing.  The only difference between the drawing and 
the machine is that the PC, Monitor and PMDX-126 BoB are all running off a 
second 220VAC current limit relay controlled by the Mill Master switch at the 
back of the machine

John Dammeyer

> -Original Message-
> From: andrew beck [mailto:andrewbeck0...@gmail.com]
> Sent: July-21-19 4:09 AM
> To: Enhanced Machine Controller (EMC)
> Subject: [Emc-users] looking for help on the best way to implement a
> Latching E stop circuit
> 
> Hi guys
> 
> I have got my cnc mill control panel working ok now just have some
> questions about the best and proper way to implement the safety E stop
> circuit and initial power on of the cnc machine
> 
> I did some searching of course, but thought I would ask here and see what
> the latest and best way is.  searching on the forum, some of the info was a
> little dated.  so if anyone has any advice I would most appreciate it.  I
> saw on Youtube what samco(skunkworks)  (I think his name is chris Radek)
> has done.  And this is pretty much what I want i think.
> 
> I think this should happen when the E stop is pushed.
> 
> Cut control power to all servos and main spindle VFD.
>  (I think I may need to just send a E stop signal to the VFD as it doesn't
> have control power that I can cut.)  It seems a big extreme to cut main
> 

Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Sam Sokolik]

I use estop type 4...

http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Sample_HAL_And_ClassicLadder

These examples use classic ladder - although I think there is a hal
component that does something similar

http://linuxcnc.org/docs/2.7/html/man/man9/estop_latch.9.html

On Sun, Jul 21, 2019 at 7:35 AM Gene Heskett  wrote:

> On Sunday 21 July 2019 07:08:52 andrew beck wrote:
>
> > Hi guys
> >
> > I have got my cnc mill control panel working ok now just have some
> > questions about the best and proper way to implement the safety E stop
> > circuit and initial power on of the cnc machine
> >
> > I did some searching of course, but thought I would ask here and see
> > what the latest and best way is.  searching on the forum, some of the
> > info was a little dated.  so if anyone has any advice I would most
> > appreciate it.  I saw on Youtube what samco(skunkworks)  (I think his
> > name is chris Radek) has done.  And this is pretty much what I want i
> > think.
> >
> > I think this should happen when the E stop is pushed.
> >
> > Cut control power to all servos and main spindle VFD.
>
> I am probably a poor one to advise since I have not a separate E-Stop
> on any of my machines, depending on the f1 and f2 keys to do it all,
> which also still leaves me subject who owns the keyboard focus.
>
> >  (I think I may need to just send a E stop signal to the VFD as it
> > doesn't have control power that I can cut.)  It seems a big extreme to
> > cut main power and possible damage the vfd with loose high voltages
> > etc.
>
> I use the F1 key to enable power and this includes the vfd by way of the
> usual 40 amp 400 volt SSR's which are easily controlled. The F2 key
> enables motion.
>
> In this way you have an onscreen tally as the the machines state.
>
> > It should tell linuxcnc that the E stop is pushed.
> > I need to set up a latching relay somehow to make sure the E stop
> > doesn't turn back on until I turn it on within linuxcnc.
> >
> > Servo Power on setup.
> >
> > I want a Button I can push which enables all the servo drives( there
> > is a Servo on pin on the servo drives)
> This can be done in the .hal file by enableing the servo drives from the
> status of the F1 key latch.
> > and then also enable the vfd
> Same here, fire the SSR's from the same signal.
> >
> > however I need to do that.  This is separate to the E stop.  Currently
> > I am only using step and direction control and I am wondering how hard
> > it will be to tie in the encoder signals to linux cnc with another
> > mesa card.  otherwise when i push the E stop I will have to re home
> > the machine.
>
> I have not tried to do that, you will have lost your home if the power is
> cut. I use steppers and with the drivers still enabled by F1, the stop
> distance is rarely more than 1 count at working speed. But can if in a
> rapid move at the time of the stop take several steps which the feeback
> encoder will miss, so you should rehome.  Servo's are another story, and
> should return to the null point when re-enabled.
>
> Here, I consider the F2 key as an E-stop as it stops motion as fast as it
> can, while leaving power on everything.
> Leaving power on the servo's, it seems to me would give a faster stop
> than killing power with its slow decay to zero.
>
> I don't think it would be too hard to rig a big red button to be the equ
> of pressing the F2 key. I made progress on getting more spare inputs,
> and am considering something like a doorbell button I can slap. But I
> can't find such a button without a light bulb across the contacts. You
> would have to cut the light bulb out and remove it, otherwise the switch
> is closed forever to a bob input pin.  One could supply that pin with
> enough pullup power to light the bulb, but most doorbell are 24 volt
> circuits, so an si diode would be needed to protect the bob's input.
>
> So I'm not "kosher" but unless lcnc doesn't have keyboard focus, it works
> for me, and the diffs are minimal. I'd have a bigger problem figuring
> out where to put the switch so its in a consistent location so muscle
> memory could be depended on once you got used to it.
>
> Believe me, there is nothing more frustrating that recognizing the sound
> of a 15 hp water pump thats suddenly single phased, and your hand is
> headed to the off button, but is still 18" from it when the lights go
> out because the 1200 amp/phase building breaker has tripped like a 12
> gauge, followed a few  milliseconds later by the realization this fix is
> going to need around $125,000 and at least two unscheduled quorums on
> the state legislature called. One to authorize the purchase, and when
> its been built and ready to ship, write the check.
>
> Yeah, broadcast power klystrons are that expensive.  Thats why we don't
> use them anymore.
>
> > anyway please sing out with any feedback you have and
> > ideas.  I would love to get some ideas here from those who have done
> > this all before.
> >
> > I am using a mesa 5i25 7i76 combo.
>
> Good 

Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Jon Elson]

On 07/21/2019 06:08 AM, andrew beck wrote:

   I
saw on Youtube what samco(skunkworks)
samco is Sam Sokolik (father and son)  They have a massive 
Kearney & Trecker horizontal mill in their garage.

   (I think his name is chris Radek)

Chris Radek is also known as Timeguy.

I can't help too much with the Mesa stuff, but the way my 
PPMC devices are set up, there is a set-reset latch in the 
motion control interface.  This is reset (to E-stop 
condition) by an estop command from the computer, a power 
fail, breaking the estop chain, or a watchdog timeout.
When the watchdog is satisfied and the estop chain is 
closed, then a computer command to come out of E-stop will 
be accepted.


LinuxCNC also has a software latch.  In the default configs, 
we set it up so that the F1 key comes out of E-stop and 
enables the servo drives, but the positioning loop doesn't 
start until F2 is pushed. This has the disadvantage that it 
leaves the drives enabled and drifting (if analog input)
if there is a following error.  One can set it so it doesn't 
come out of E-stop  until F2 is pressed, but that makes the 
transient a bit heavier when everything happens at once.


Jon


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Re: [Emc-users] looking for help on the best way to implement a Latching E stop circuit

[Gene Heskett]

On Sunday 21 July 2019 07:08:52 andrew beck wrote:

> Hi guys
>
> I have got my cnc mill control panel working ok now just have some
> questions about the best and proper way to implement the safety E stop
> circuit and initial power on of the cnc machine
>
> I did some searching of course, but thought I would ask here and see
> what the latest and best way is.  searching on the forum, some of the
> info was a little dated.  so if anyone has any advice I would most
> appreciate it.  I saw on Youtube what samco(skunkworks)  (I think his
> name is chris Radek) has done.  And this is pretty much what I want i
> think.
>
> I think this should happen when the E stop is pushed.
>
> Cut control power to all servos and main spindle VFD.

I am probably a poor one to advise since I have not a separate E-Stop
on any of my machines, depending on the f1 and f2 keys to do it all, 
which also still leaves me subject who owns the keyboard focus.
   
>  (I think I may need to just send a E stop signal to the VFD as it
> doesn't have control power that I can cut.)  It seems a big extreme to
> cut main power and possible damage the vfd with loose high voltages
> etc.

I use the F1 key to enable power and this includes the vfd by way of the 
usual 40 amp 400 volt SSR's which are easily controlled. The F2 key 
enables motion.

In this way you have an onscreen tally as the the machines state.

> It should tell linuxcnc that the E stop is pushed.
> I need to set up a latching relay somehow to make sure the E stop
> doesn't turn back on until I turn it on within linuxcnc.
>
> Servo Power on setup.
>
> I want a Button I can push which enables all the servo drives( there
> is a Servo on pin on the servo drives)
This can be done in the .hal file by enableing the servo drives from the 
status of the F1 key latch. 
> and then also enable the vfd
Same here, fire the SSR's from the same signal.
> 
> however I need to do that.  This is separate to the E stop.  Currently
> I am only using step and direction control and I am wondering how hard
> it will be to tie in the encoder signals to linux cnc with another
> mesa card.  otherwise when i push the E stop I will have to re home
> the machine.

I have not tried to do that, you will have lost your home if the power is 
cut. I use steppers and with the drivers still enabled by F1, the stop 
distance is rarely more than 1 count at working speed. But can if in a 
rapid move at the time of the stop take several steps which the feeback 
encoder will miss, so you should rehome.  Servo's are another story, and 
should return to the null point when re-enabled.

Here, I consider the F2 key as an E-stop as it stops motion as fast as it 
can, while leaving power on everything.
Leaving power on the servo's, it seems to me would give a faster stop 
than killing power with its slow decay to zero.

I don't think it would be too hard to rig a big red button to be the equ 
of pressing the F2 key. I made progress on getting more spare inputs, 
and am considering something like a doorbell button I can slap. But I 
can't find such a button without a light bulb across the contacts. You 
would have to cut the light bulb out and remove it, otherwise the switch 
is closed forever to a bob input pin.  One could supply that pin with 
enough pullup power to light the bulb, but most doorbell are 24 volt 
circuits, so an si diode would be needed to protect the bob's input.

So I'm not "kosher" but unless lcnc doesn't have keyboard focus, it works 
for me, and the diffs are minimal. I'd have a bigger problem figuring 
out where to put the switch so its in a consistent location so muscle 
memory could be depended on once you got used to it.

Believe me, there is nothing more frustrating that recognizing the sound 
of a 15 hp water pump thats suddenly single phased, and your hand is 
headed to the off button, but is still 18" from it when the lights go 
out because the 1200 amp/phase building breaker has tripped like a 12 
gauge, followed a few  milliseconds later by the realization this fix is 
going to need around $125,000 and at least two unscheduled quorums on 
the state legislature called. One to authorize the purchase, and when 
its been built and ready to ship, write the check. 

Yeah, broadcast power klystrons are that expensive.  Thats why we don't 
use them anymore.

> anyway please sing out with any feedback you have and 
> ideas.  I would love to get some ideas here from those who have done
> this all before.
>
> I am using a mesa 5i25 7i76 combo.

Good combo, I'm using it twice myself.

> And I have all sorts of contactors etc.
>
> Regards
>
> Andrew
>
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