Re: [Emc-users] One servo system

[Johann Beukes]

Hi Marius
Maybe a small Delta Plc from Electro Mechanica could do the job.
I managed to control a stepper with one of them.

On Wed, 28 Mar 2018, 17:46 Marius Liebenberg, 
wrote:

> Hi all
> I have to put together a system that will use one servo to drive a small
> platform over a distance of 6m at a speed of about 25km/h or 8m/s or
> there about.
>
> I feel that using a full computer and mesa card for just one axis that
> does not need a display sounds a bit excessive. The question is what are
> the other options if any.
>
>
>
> -
> Regards / Groete
>
> Marius D. Liebenberg
> +27 82 698 3251
> +27 12 743 6064
>
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Re: [Emc-users] Korean R8's arrived

[Gene Heskett]

On Wednesday 04 April 2018 21:59:05 Ken Strauss wrote:

> Link to the vendor, please?

This isn't the same size as I bought, I bought 7/8" but its the same 
vendor. I couldn't find a link to his ebay store on the shipping notice.



> > -Original Message-
> > From: Gene Heskett [mailto:ghesk...@shentel.net]
> > Sent: Wednesday, April 04, 2018 7:53 PM
> > To: Enhanced Machine Controller (EMC)
> > Subject: [Emc-users] Korean R8's arrived
> >
> > Greetings all;
> >
> > I have not spun them up to measure them, but these are the purtiest
> > R8's I ever laid my eyes on. The 7/16x20 threads are far better
> > formed than anything else in my rack of R8's. Coming by USPS, they
> > are cold so I'll
>
> leave
>
> > them in the styro shippers till they have warmed up.  A small pill
> > bottle
>
> sized
>
> > bag of silica gel would have been nice. I put one in the one I
> > opened.
> >
> > --
> > 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)
> > Genes Web page 
>
> --
>-- --
>
> > Check out the vibrant tech community on one of the world's most
> > engaging tech sites, Slashdot.org! http://sdm.link/slashdot
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-- 
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--
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 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

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Re: [Emc-users] Korean R8's arrived

[Ken Strauss]

Link to the vendor, please?

> -Original Message-
> From: Gene Heskett [mailto:ghesk...@shentel.net]
> Sent: Wednesday, April 04, 2018 7:53 PM
> To: Enhanced Machine Controller (EMC)
> Subject: [Emc-users] Korean R8's arrived
>
> Greetings all;
>
> I have not spun them up to measure them, but these are the purtiest R8's I
> ever laid my eyes on. The 7/16x20 threads are far better formed than
> anything else in my rack of R8's. Coming by USPS, they are cold so I'll
leave
> them in the styro shippers till they have warmed up.  A small pill bottle
sized
> bag of silica gel would have been nice. I put one in the one I opened.
>
> --
> 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)
> Genes Web page 
>
>

--
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Re: [Emc-users] ESTOP and Drive Enable handling.

[John Dammeyer]

The way you have the RS485 wired with the two other resistors does bias it
in that direction.   I disconnected the two wires  and left them floating
and step/dir still function.  Definitely not what we want.But if you
didn't have the two resistors around the 1K would the output not default to
low?  Normally termination for an RS485 circuit is between 100 and 120 ohms.

John



> -Original Message-
> From: Rene Hopf [mailto:reneh...@mac.com]
> Sent: April-04-18 4:16 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] ESTOP and Drive Enable handling.
> 
> 
> > On 4. Apr 2018, at 21:57, John Dammeyer 
> wrote:
> >
> > The STMBL AC Servo drive I'm currently working with has an ENABLE high
> input.  So when Low it's disabled and stepping pulses can't move the
motor.
> 
> its not supposed to be like that. it should be active low. I will ad a
inverted
> pin to the software.
> I didn't think about the fact that rs485 termination defaults to 1...
> you are the first one using the diff enable signal, most use the smart
serial
> connection, and the one setup with step/dir uses a single ended input as
> enable.
> 
> Rene
>

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[Emc-users] Korean R8's arrived

[Gene Heskett]

Greetings all;

I have not spun them up to measure them, but these are the purtiest R8's 
I ever laid my eyes on. The 7/16x20 threads are far better formed than 
anything else in my rack of R8's. Coming by USPS, they are cold so I'll 
leave them in the styro shippers till they have warmed up.  A small pill 
bottle sized bag of silica gel would have been nice. I put one in the 
one I opened.

-- 
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)
Genes Web page 

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Re: [Emc-users] ESTOP and Drive Enable handling.

[Rene Hopf]

> On 4. Apr 2018, at 21:57, John Dammeyer  wrote:
> 
> The STMBL AC Servo drive I'm currently working with has an ENABLE high input. 
>  So when Low it's disabled and stepping pulses can't move the motor.

its not supposed to be like that. it should be active low. I will ad a inverted 
pin to the software.
I didn't think about the fact that rs485 termination defaults to 1...
you are the first one using the diff enable signal, most use the smart serial 
connection, and the one setup with step/dir uses a single ended input as enable.

Rene
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Re: [Emc-users] ESTOP and Drive Enable handling.

[Chris Albertson]

Ideally the e-stop would be fail safe.   This means if a wire comes
loose, something gets shorted or whatever the machine stops.It is
designed so that some positive action is required to make the motors
spin.

Alarm systems are like this to.  The normal signal is a "hot" wire so
that if the cable is cut the dead wire triggers the alarm.   The alarm
is actively held off.


There is also the question of where to place the e-stop.   Should the
e-stop signal go to the control computer, the drivers or the motors.?
  I think the closer to the motors you can get the more reliable it
is.  Certainly a relay that requires power to keep the DC motor power
connected is going to be very reliable.  But it is also a big
expensive device that must be mounted close to the machine.

But I just started design of a wireless hand controller and thought it
would be nice to have a stop button on it.   After all my thumb would
be just inches away and I could press stop quickly if needed.  But the
problem is that a LOT has to be working for this stop button to work.
 It would not have high reliability especially during development and
debugging.

My thinking is that a layered approach might be good.   The reliable
e-stop is mounted on the machine but a less reliable stop that is
physically close to the operator might be very useful.

In one case I have a 3D printer soon to be moved to a remove location.
It will have a webcam to show me what is going on.  I could get to the
printer in about 3 minutes and stop it or I could send a "stop" over
the WiFi network and stop it in seconds.   Think it is best to have
both methods.

On Wed, Apr 4, 2018 at 12:57 PM, John Dammeyer  wrote:
> In the past ESTOP appeared to be pretty simple a 12V or 24V control signal 
> was routed through any number of Normally Closed (NC) switches and then run 
> into relays and or opto-isolated inputs. Any ESTOP even would then interrupt 
> the control voltage and relays would open dropping all power.
>
> However things have changed a bit.  With PCs in the mix, rules changed and 
> PCs and control systems could stay active but anything in hardware dangerous 
> to humans was now switched off by the signal interruption.
>
> Enter a wide variety of motor controllers.  The HP_UHU has an active low 
> ESTOP IN/OUT signal.   A low on the ESTOP input shuts off power to the drive 
> control logic.  If the drive has  a fault, it brings this line low too and 
> any other HP_UHU drives are also then pulled into ESTOP mode.   I think this 
> would be better identified as ENABLE rather than ESTOP.
>
> The STMBL AC Servo drive I'm currently working with has an ENABLE high input. 
>  So when Low it's disabled and stepping pulses can't move the motor.
>
> The Gecko Servo drive is disabled by bringing Terminal 5 ERR/RES low.
> http://www.geckodrive.com/support/motor-control-manuals/dc-servo-drives/g320-rev-7.html
>
> The disable is the same on the G250x series.  Bring it low to disable the 
> drive.
>
> So it seems the various drives all use a logic low or contact to ground to 
> disable the drive and let the input float or bring it high to enable the 
> drive.
>
> So where does the ESTOP fit into these systems?  Are people still wiring up 
> an ESTOP to remove driver power (up to 80V for GECKO, as much as 100V or more 
> for DC/AC Servos).
>
> And if the drives enable pin is something controlled by the PC or CNC 
> controller, when is it allowed to be valid?  Should all DC voltages be there 
> first for a given amount of time or should the drives power up and function 
> if the enable pin is already active even if the supply lags behind the enable 
> signal?
>
> Lots of questions.
>
> Thanks
> John
>
>
>
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Redondo Beach, California

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Re: [Emc-users] ESTOP and Drive Enable handling.

[Peter C. Wallace]

On Wed, 4 Apr 2018, John Dammeyer wrote:


Date: Wed, 4 Apr 2018 12:57:03 -0700
From: John Dammeyer 
Reply-To: "Enhanced Machine Controller (EMC)"

To: "'Enhanced Machine Controller (EMC)'" 
Subject: [Emc-users] ESTOP and Drive Enable handling.

In the past ESTOP appeared to be pretty simple a 12V or 24V control signal 
was routed through any number of Normally Closed (NC) switches and then run 
into relays and or opto-isolated inputs. Any ESTOP even would then interrupt 
the control voltage and relays would open dropping all power.


However things have changed a bit.  With PCs in the mix, rules changed and 
PCs and control systems could stay active but anything in hardware dangerous 
to humans was now switched off by the signal interruption.


Enter a wide variety of motor controllers.  The HP_UHU has an active low 
ESTOP IN/OUT signal.  A low on the ESTOP input shuts off power to the drive 
control logic.  If the drive has a fault, it brings this line low too and 
any other HP_UHU drives are also then pulled into ESTOP mode.  I think this 
would be better identified as ENABLE rather than ESTOP.


The STMBL AC Servo drive I'm currently working with has an ENABLE high 
input.  So when Low it's disabled and stepping pulses can't move the motor.


The Gecko Servo drive is disabled by bringing Terminal 5 ERR/RES low. 
http://www.geckodrive.com/support/motor-control-manuals/dc-servo-drives/g320-rev-7.html


The disable is the same on the G250x series.  Bring it low to disable the 
drive.


So it seems the various drives all use a logic low or contact to ground to 
disable the drive and let the input float or bring it high to enable the 
drive.


So where does the ESTOP fit into these systems?  Are people still wiring up 
an ESTOP to remove driver power (up to 80V for GECKO, as much as 100V or 
more for DC/AC Servos).


And if the drives enable pin is something controlled by the PC or CNC 
controller, when is it allowed to be valid?  Should all DC voltages be there 
first for a given amount of time or should the drives power up and function 
if the enable pin is already active even if the supply lags behind the 
enable signal?


Lots of questions.

Thanks
John



I think low cost/low power/not so dangerous drives (Gecko, Leadshine, etc step 
drives ) use a disable pin rather than an enable pin because a large number of 
users ignore the drive enable/disable so they will "just work" when 
unconnected.


Some older analog servo drives have disable pins also (which is a quite bad 
idea) If you want to use drive with a disable input and you want to disable it 
with EStop or a LinuxCNC signal I would use a relay (or a form B OPTO) to 
disable the drive until EStop and LinuxCNC give the go-ahead.


LinuxCNC has an enable signal (axis/joint.n.amp-enable-out) thats useful for 
this function, but drive enable should be guaranteed to revert to the disabled 
state if LinuxCNC or the host PC crashes or loses power so also requires a 
watchdog or chargepump circuit.





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Mesa Electronics

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Re: [Emc-users] For the attention of Anyone using a 7i90 through SPI

[Gene Heskett]

On Wednesday 04 April 2018 16:17:08 Peter C. Wallace wrote:

> On Wed, 4 Apr 2018, Gene Heskett wrote:
> > Date: Wed, 4 Apr 2018 07:40:53 -0400
> > From: Gene Heskett 
> > Reply-To: "Enhanced Machine Controller (EMC)"
> > 
> > To: emc-users@lists.sourceforge.net
> > Subject: Re: [Emc-users] For the attention of Anyone using a 7i90
> > through SPI
> >
> > On Wednesday 04 April 2018 05:20:17 andy pugh wrote:
> >> A bug in the smart-serial driver was, until recently, masking a bug
> >> in the 7i90 SPI firmware.
> >>
> >> Mesa have fixed the bug and re-issued the bitfiles.
> >>
> >> The problem probably only affects systems using a 7i90 controlled
> >> through an SPI link and _also_ using smart-serial peripherals
> >> connected to the 7i90.
> >>
> >> More details on the bug tracker here:
> >> https://github.com/LinuxCNC/linuxcnc/issues/412#issuecomment-377253
> >>608
> >
> > I've not downloaded the new bit files yet. But it needs the 7i90
> > reset to an epp interface I'd assume in order for mesaflash to be
> > able to reprogram the card, correct?
>
> Its depends, some hosts can update firmware via SPI (requires
> /dev/spidev) but I think RSPI is an exception but am not sure
>
> > That imply's a complete mechanical disassembly because the 7i90 is
> > at the bottom of a stack of cards, and will need connected to a
> > machine with a parport.
> >
> > With the pi turned upside down, which allows an spi cable only about
> > an inch long.  And I am not using any smart serial stuff, my 7i90's
> > gpio's are all directly connected to the hardware. So is it even
> > recommended that I reflash the 7i90 in my lathes application?  IOW,
> > if the fixed driver (because apt has updated it,) is used with the
> > unfixed firmware, is there a detectable effect/problem?
> >
> > Because the teardown to do that reflash is a cast iron pita, I'd be
> > time and effort ahead to order another 7i90HD, program it, and just
> > swap it out, I might be able to do that in one long day. Maybe 2,
> > depending on how many times Dee interrupts me as she's home now, but
> > still hopping 4" at a time on her good leg and a walker just to get
> > to the potty chair. So I'm chief cook and bottle washer in addition
> > to potty chair dumper/cleaner. :)
> >
> > What is needed for this, is a mesaflash for spi. Is that even
> > possible to do, Peter?
>
> If you dont see any issues and dont use sserial devices I woudl not
> bother updating the firmware

 Thank you Peter and Cheers, Gene Heskett

-- 
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--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

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[Emc-users] ESTOP and Drive Enable handling.

[John Dammeyer]

In the past ESTOP appeared to be pretty simple a 12V or 24V control signal was 
routed through any number of Normally Closed (NC) switches and then run into 
relays and or opto-isolated inputs. Any ESTOP even would then interrupt the 
control voltage and relays would open dropping all power.

However things have changed a bit.  With PCs in the mix, rules changed and PCs 
and control systems could stay active but anything in hardware dangerous to 
humans was now switched off by the signal interruption.

Enter a wide variety of motor controllers.  The HP_UHU has an active low ESTOP 
IN/OUT signal.   A low on the ESTOP input shuts off power to the drive control 
logic.  If the drive has  a fault, it brings this line low too and any other 
HP_UHU drives are also then pulled into ESTOP mode.   I think this would be 
better identified as ENABLE rather than ESTOP.

The STMBL AC Servo drive I'm currently working with has an ENABLE high input.  
So when Low it's disabled and stepping pulses can't move the motor.

The Gecko Servo drive is disabled by bringing Terminal 5 ERR/RES low.  
http://www.geckodrive.com/support/motor-control-manuals/dc-servo-drives/g320-rev-7.html

The disable is the same on the G250x series.  Bring it low to disable the 
drive.  

So it seems the various drives all use a logic low or contact to ground to 
disable the drive and let the input float or bring it high to enable the drive.

So where does the ESTOP fit into these systems?  Are people still wiring up an 
ESTOP to remove driver power (up to 80V for GECKO, as much as 100V or more for 
DC/AC Servos).

And if the drives enable pin is something controlled by the PC or CNC 
controller, when is it allowed to be valid?  Should all DC voltages be there 
first for a given amount of time or should the drives power up and function if 
the enable pin is already active even if the supply lags behind the enable 
signal?

Lots of questions.

Thanks
John 



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Re: [Emc-users] For the attention of Anyone using a 7i90 through SPI

[Peter C. Wallace]

On Wed, 4 Apr 2018, Gene Heskett wrote:


Date: Wed, 4 Apr 2018 07:40:53 -0400
From: Gene Heskett 
Reply-To: "Enhanced Machine Controller (EMC)"

To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] For the attention of Anyone using a 7i90 through SPI

On Wednesday 04 April 2018 05:20:17 andy pugh wrote:


A bug in the smart-serial driver was, until recently, masking a bug in
the 7i90 SPI firmware.

Mesa have fixed the bug and re-issued the bitfiles.

The problem probably only affects systems using a 7i90 controlled
through an SPI link and _also_ using smart-serial peripherals
connected to the 7i90.

More details on the bug tracker here:
https://github.com/LinuxCNC/linuxcnc/issues/412#issuecomment-377253608


I've not downloaded the new bit files yet. But it needs the 7i90 reset to
an epp interface I'd assume in order for mesaflash to be able to
reprogram the card, correct?


Its depends, some hosts can update firmware via SPI (requires /dev/spidev) but 
I think RSPI is an exception but am not sure




That imply's a complete mechanical disassembly because the 7i90 is at the
bottom of a stack of cards, and will need connected to a machine with a
parport.

With the pi turned upside down, which allows an spi cable only about an
inch long.  And I am not using any smart serial stuff, my 7i90's gpio's
are all directly connected to the hardware. So is it even recommended
that I reflash the 7i90 in my lathes application?  IOW, if the fixed
driver (because apt has updated it,) is used with the unfixed firmware,
is there a detectable effect/problem?

Because the teardown to do that reflash is a cast iron pita, I'd be time
and effort ahead to order another 7i90HD, program it, and just swap it
out, I might be able to do that in one long day. Maybe 2, depending on
how many times Dee interrupts me as she's home now, but still hopping 4"
at a time on her good leg and a walker just to get to the potty chair.
So I'm chief cook and bottle washer in addition to potty chair
dumper/cleaner. :)

What is needed for this, is a mesaflash for spi. Is that even possible to
do, Peter?



If you dont see any issues and dont use sserial devices I woudl not bother 
updating the firmware





Thanks and Cheers, Gene Heskett
--
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soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

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Mesa Electronics

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Re: [Emc-users] Making a steper pulse generator, would like comments

[Gene Heskett]

On Wednesday 04 April 2018 12:33:26 Jon Elson wrote:

> On 04/03/2018 11:50 PM, Chris Albertson wrote:
> > Yes the faster you go the bigger the jumps.   With my 1MHz clock I
> > can only make pulses with periods that are a whole number of
> > microseconds.
> >
> > So I ask again:  What is the fastest step rate you actually use with
> > a real machine?
>
> It TOTALLY depends!  There are guys running delta 3D
> printers with NEMA 17 motors that probably go to insane
> RPMs, and thus really high step rates with microstepping
> drives.
>
> > What is needed?  Do people run motors at 100,000 steps per second?
>
> 100K (micro) steps/sec is 10K full steps/sec with a Gecko
> driver. 10K full steps/sec with a standard 1.8 degree motor
> is 50 RPS or 3000 RPM, so that is quite possible with a good
> driver and NEMA 17 motor.
>
And I have made 3300 revs on a nema 23, 45 volts into a 2m542 driver. No 
usable torque, but it ran. I don't recall the step divisor ATM but it 
was not less than a /8.

> > What I'm guessing is that it is rare to run as high as 10K steps per
> > second.I could be wrong, so I'm wanting to hear from people who
> > are running real machines.
>
> 10K (micro) steps/second would be 5 RPM or 600 RPM, VERY
> normal speeds even with much larger motors.  If you
> direct-drive a 5 TPI screw at 600 RPM, you get 120 IPM,
> which is quite normal.

Absolutely.

> So, 10K steps/sec is NOT at all rare when using
> microstepping drives.
>
> > To say this using  MK or LinixCNC terminology what is the fastest
> > usable "base rate"?I am using a 1 uS (or 1MHz) base rate.   Is
> > that fast enough?

IMO, no. Mesa's cards use a higher frequency, in some cases I think 50 
MHZ, (or is that only for encoder sampling) so the timing jitters even 
when its doing a semi-random step to generate an in between pulse train, 
the timeing errors are under 1%.

> With Machinekit on the Beagle Bone, the PRU can generate
> steps a lot faster than X86 software stepping, and there is
> no base thread.  I don't know the max rate you can get, but
> you can certainly get step rates well into the 10's of KHz,
> while doing other stuff, too.
>
> Jon

-- 
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)
Genes Web page 

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Re: [Emc-users] One servo system

[andy pugh]

On 4 April 2018 at 09:26, Marius Liebenberg  wrote:

> Would the ladder logic route be good enough or are there some other
> suggestions?

it doesn't matter if there is "wasted" code running on the controller.
If you run a whole LinuxCNC instance on the board, and that does
nothing more than MDI a G1 move when the button is pressed ten nothing
is really lost. It isn't as if you could be doing anything else useful
with the "wasted" memory in the device.
In the flip-side. If the task becomes more complicated in future then
you can be confident that the infrastucture exists to handle that
complexity.

So I would either go for a standalone smart servo with built-in motion
controller and driver, or a complete LinuxCNC installation on a small
board.

-- 
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] For the attention of Anyone using a 7i90 through SPI

[Gene Heskett]

On Wednesday 04 April 2018 05:20:17 andy pugh wrote:

> A bug in the smart-serial driver was, until recently, masking a bug in
> the 7i90 SPI firmware.
>
> Mesa have fixed the bug and re-issued the bitfiles.
>
> The problem probably only affects systems using a 7i90 controlled
> through an SPI link and _also_ using smart-serial peripherals
> connected to the 7i90.
>
> More details on the bug tracker here:
> https://github.com/LinuxCNC/linuxcnc/issues/412#issuecomment-377253608

I've not downloaded the new bit files yet. But it needs the 7i90 reset to 
an epp interface I'd assume in order for mesaflash to be able to 
reprogram the card, correct?

That imply's a complete mechanical disassembly because the 7i90 is at the 
bottom of a stack of cards, and will need connected to a machine with a 
parport. 

With the pi turned upside down, which allows an spi cable only about an 
inch long.  And I am not using any smart serial stuff, my 7i90's gpio's 
are all directly connected to the hardware. So is it even recommended 
that I reflash the 7i90 in my lathes application?  IOW, if the fixed 
driver (because apt has updated it,) is used with the unfixed firmware, 
is there a detectable effect/problem?

Because the teardown to do that reflash is a cast iron pita, I'd be time 
and effort ahead to order another 7i90HD, program it, and just swap it 
out, I might be able to do that in one long day. Maybe 2, depending on 
how many times Dee interrupts me as she's home now, but still hopping 4" 
at a time on her good leg and a walker just to get to the potty chair. 
So I'm chief cook and bottle washer in addition to potty chair 
dumper/cleaner. :)

What is needed for this, is a mesaflash for spi. Is that even possible to 
do, Peter?

Thanks and 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)
Genes Web page 

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[Emc-users] For the attention of Anyone using a 7i90 through SPI

[andy pugh]

A bug in the smart-serial driver was, until recently, masking a bug in
the 7i90 SPI firmware.

Mesa have fixed the bug and re-issued the bitfiles.

The problem probably only affects systems using a 7i90 controlled
through an SPI link and _also_ using smart-serial peripherals
connected to the 7i90.

More details on the bug tracker here:
https://github.com/LinuxCNC/linuxcnc/issues/412#issuecomment-377253608

-- 
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] One servo system

[Marius Liebenberg]

I just looked at the PocketBeagle and it seems to be a good choice for 
servo or stepper.
It will have to be headless so I would imagine that I will be using 
ladder to control the system with.


The track length is 6m, a button is pressed and I accelerate to 8m/s and 
stop at the other end waiting for a command to do the same in the 
opposite direction. Machine must home in the one axis on demand as well.


Would the ladder logic route be good enough or are there some other 
suggestions?


-- Original Message --
From: "Alexander Rössler" 
To: "Enhanced Machine Controller (EMC)" 


Cc: "Marius Liebenberg" 
Sent: 2018-04-04 09:24:43
Subject: Re: [Emc-users] One servo system

Machinekit + PocketBeagle is good combo if you are looking for 
something

running Linux.

Chris Albertson writes:


 Of course.   Write a PID based control loop and put it an something
 like an Arduino.  I've done this a few times the control the wheels 
of

 a mobile robot.

 The details depend on the interfaces to botkhthe motoring the higher
 level control


 As for higher level control...  Is it a human using a joystick or 
some

 kind of automation that does the same thing repetivity  or must the
 device interact with the environment some how.  Perhaps opening a for
 as a person approaches.

 Then I have to ask what kind of hardware driver you have.   Some
 drivers do most of the work for you.  These might take a
 step/direction pulse, r have an analog input.  But other drivers are
 just an H-Bridge and raw encoder signals.This is the kind of
 serves I use.   I end u using a small micro controler (Arduino or
 ARM-M) and relaying on a PID library.

 In ant case most of your effort will be spent in the interfaces not
 the actual PID control loop as that is just a few calls to a PID
 library

 On Wed, Mar 28, 2018 at 8:15 AM, Marius Liebenberg
  wrote:

 Hi all
 I have to put together a system that will use one servo to drive a 
small
 platform over a distance of 6m at a speed of about 25km/h or 8m/s or 
there

 about.

 I feel that using a full computer and mesa card for just one axis 
that does
 not need a display sounds a bit excessive. The question is what are 
the

 other options if any.



 -
 Regards / Groete

 Marius D. Liebenberg
 +27 82 698 3251
 +27 12 743 6064
 
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--
Alexander Rössler
HMI Expert at Rössler Systems
Tel: +43 680 1348338
Web: https://roessler.systems
Blog: https://machinekoder.com
alexander@roessler.systems
Lebnergasse 1/7/7
1210 Wien - Austria
ATU72251528

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Re: [Emc-users] One servo system

[Alexander Rössler]

Machinekit + PocketBeagle is good combo if you are looking for something
running Linux.

Chris Albertson writes:

> Of course.   Write a PID based control loop and put it an something
> like an Arduino.  I've done this a few times the control the wheels of
> a mobile robot.
>
> The details depend on the interfaces to botkhthe motoring the higher
> level control
>
>
> As for higher level control...  Is it a human using a joystick or some
> kind of automation that does the same thing repetivity  or must the
> device interact with the environment some how.  Perhaps opening a for
> as a person approaches.
>
> Then I have to ask what kind of hardware driver you have.   Some
> drivers do most of the work for you.  These might take a
> step/direction pulse, r have an analog input.  But other drivers are
> just an H-Bridge and raw encoder signals.This is the kind of
> serves I use.   I end u using a small micro controler (Arduino or
> ARM-M) and relaying on a PID library.
>
> In ant case most of your effort will be spent in the interfaces not
> the actual PID control loop as that is just a few calls to a PID
> library
>
> On Wed, Mar 28, 2018 at 8:15 AM, Marius Liebenberg
>  wrote:
>> Hi all
>> I have to put together a system that will use one servo to drive a small
>> platform over a distance of 6m at a speed of about 25km/h or 8m/s or there
>> about.
>>
>> I feel that using a full computer and mesa card for just one axis that does
>> not need a display sounds a bit excessive. The question is what are the
>> other options if any.
>>
>>
>>
>> -
>> Regards / Groete
>>
>> Marius D. Liebenberg
>> +27 82 698 3251
>> +27 12 743 6064
>> --
>> Check out the vibrant tech community on one of the world's most
>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>> ___
>> Emc-users mailing list
>> Emc-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/emc-users


-- 
Alexander Rössler
HMI Expert at Rössler Systems
Tel: +43 680 1348338
Web: https://roessler.systems
Blog: https://machinekoder.com
alexander@roessler.systems
Lebnergasse 1/7/7
1210 Wien - Austria
ATU72251528

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