-
From: Alex Joni [EMAIL PROTECTED]
To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net
Sent: Monday, October 29, 2007 9:54 PM
Subject: Re: [Emc-users] Ethernet I/O
I finally found this reference:
http://www.rtcmagazine.com/home/article.php?id=100822pg=2
The slave controller
Do those ARM processors include floating point? My guess is not. Those
70+ MIPs might not go as far as you think if you have to do floating
point in software. I'd rather not go to the alternative of converting
everything to fixed point.
Ken
On Tue, Oct 30, 2007 at 12:31:18PM -0600, Jon Elson
I have been using several Wafer LX 800 for embedded development work
over the course of the last year, they have dual ethernet, compact flash
slot on the back, use regular laptop ram and have both parallel and gpio
for ouput. They are a bit more expensive than basic types but i'm sure
they can be
] Ethernet I/O
Peter C. Wallace wrote:
$300, using pluggable terminal strips ;)
Heh, We told Digikey the Avnet price and they came down to ~10.00...
For a parallel port replacement Ethernet, maybe a thing to consider is just a
single point to point link to the (multi axis) endpoint and some very
Mark Pictor wrote:
--- Peter C. Wallace [EMAIL PROTECTED] wrote:
For a parallel port replacement Ethernet, maybe a thing to
consider is just a
single point to point link to the (multi axis) endpoint and some
very simple
master slave protocol. The slave would get a packet, unpack to
hardware
Peter C. Wallace wrote:
But for point to point, all you do is setup the packet in memory, setup the
DMA controller and tweak the Enet chip
But, the Ethernet driver has to be running as a process under
the real time system.
Jon
] Ethernet I/O
Peter C. Wallace wrote:
But for point to point, all you do is setup the packet in memory, setup the
DMA controller and tweak the Enet chip
But, the Ethernet driver has to be running as a process under
the real time system.
Jon
All I'm saying is that for raw packets (no TCPIP
: Re: [Emc-users] Ethernet I/O
Peter C. Wallace wrote:
But for point to point, all you do is setup the packet in memory, setup the
DMA controller and tweak the Enet chip
But, the Ethernet driver has to be running as a process under
the real time system.
Jon
All I'm saying is that for raw
Rafael Skodlar wrote:
This brings up another option, build an open source EMC controller
PCI[e] card with slow, medium and high speed ports that could be used to
control buses. Speeds would need to be determined based on what is
required for machine world. If build with an FPGA, it would
Jarl Stefansson wrote:
I would like to point out that ARM processors aren't the only way to go
embedded, there are very decent x86 embedded systems available with AMD
(Geode LX/NX) and VIA (CN/CX/C7/Eden) CPUs.
System based on these can be sourced for less than $100 in bulk and as
an added
Rufi wrote:
hello guys,
I like to point you to our dspMC motion controller
www.vitalsystem.com/dspMC http://www.vitalsystem.com/dspMC.
the board has a blackfin DSP from Analog Devices. the Blackfin dsp is
supported by Gnu/Gcc comipler and a linux port is available at
Jarl Stefansson wrote:
I would like to point out that ARM processors aren't the only way to go
embedded, there are very decent x86 embedded systems available with AMD
(Geode LX/NX) and VIA (CN/CX/C7/Eden) CPUs.
If you're thinking of the small-footprint PC-like systems, you probably
need to
$300, using pluggable terminal strips ;)
Heh, We told Digikey the Avnet price and they came down to ~10.00...
For a parallel port replacement Ethernet, maybe a thing to consider is just a
single point to point link to the (multi axis) endpoint and some very simple
master slave protocol. The
-users@lists.sourceforge.net
Sent: Tuesday, October 30, 2007 7:53:51 PM
Subject: Re: [Emc-users] Ethernet I/O
Rufi wrote:
hello guys,
I like to point you to our dspMC motion controller
www.vitalsystem.com/dspMC http://www.vitalsystem.com/dspMC.
the board has a blackfin DSP from Analog
PM
Subject: Re: [Emc-users] Ethernet I/O
On Tue, 30 Oct 2007, Javid Butler wrote:
Date: Tue, 30 Oct 2007 19:36:35 -0600
From: Javid Butler [EMAIL PROTECTED]
Reply-To: Enhanced Machine Controller (EMC)
emc-users@lists.sourceforge.net
To: Enhanced Machine Controller (EMC) emc-users
Stephen Wille Padnos wrote:
Jon Elson wrote:
I think the flash is actually slower than external memory access. The
datasheet for one of these chips (don't remember which one) said that it
was limited to ~55 MHz operating from flash, but 175-200 MHz from RAM.
I don't recall if
Peter C. Wallace wrote:
$300, using pluggable terminal strips ;)
Heh, We told Digikey the Avnet price and they came down to ~10.00...
For a parallel port replacement Ethernet, maybe a thing to consider is just a
single point to point link to the (multi axis) endpoint and some very
Subject: Re: [Emc-users] Ethernet I/O
Jon wrote-
Given all the required overhead to read and write multiple
packets, it is already pretty close to chewing up a whole
millisecond, and there's no way it could handle even 5 KHz
servo update rate. So, I really don't think CAN is a good
candidate.
I
Jon Elson wrote:
Jarl Stefansson wrote:
I would like to point out that ARM processors aren't the only way to go
embedded, there are very decent x86 embedded systems available with AMD
(Geode LX/NX) and VIA (CN/CX/C7/Eden) CPUs.
As others have pointed out, miniITX and such do not
On Fri, Oct 26, 2007 at 08:37:47PM -0500, Javid Butler wrote:
The real problem is the endpoint device. There will have to be some way to
decode the signals from the ethernet into the actual drives. It will
probably be a while before cost effective drives are available with ethernet
inputs.
06470Fax: (203)426-9138
http://www.MarkKenny.com
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Jon Elson
Sent: Sunday, October 28, 2007 10:44 PM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Ethernet I/O
Kenneth
)
Subject: Re: [Emc-users] Ethernet I/O
On Fri, Oct 26, 2007 at 08:37:47PM -0500, Javid Butler wrote:
The real problem is the endpoint device. There will have to be some way to
decode the signals from the ethernet into the actual drives. It will
probably be a while before cost effective drives
Stephen Wille Padnos wrote:
Jon Elson wrote:
As long as you could throttle traffic on that ethernet segment,
so a network file transfer, for instance, couldn't bog down the
ethernet, then that would work.
No, it wouldn't (not necessarily).
You'd also have to set the MTU pretty low. A
Rafael Skodlar wrote:
I would not want to rely on UDP for real time applications unless it's
used on an isolated network with a limited number of well behaving
nodes.
Yes, you would have to do it that way.
Gigabit ethernet would be better but then which microcontroller will be
able to
Jon, Rafael, et al
IIRC CAN is 1 Mbit/sec.
Philosophically I'd opt for KISS. (keep it simple stupid).
No more complexity than is necessary to get the job done.
To me that sounds a lot like raw packets point to point.
Dave
On Oct 29, 2007, at 10:33 AM, Jon Elson wrote:
Rafael Skodlar wrote:
Erik Christiansen wrote:
On Fri, Oct 26, 2007 at 08:37:47PM -0500, Javid Butler wrote:
The real problem is the endpoint device. There will have to be some way to
decode the signals from the ethernet into the actual drives. It will
probably be a while before cost effective drives are available
CAN is indeed a maximum 1Mbps, however about 50% of that is overhead, so
the actual data bandwidth is more like a max of 500kbps. This is over a
distance of something like 40 meters.
CAN only defines the physical connection and message frame format. All
the bit stuffing, sync, acknowlegements and
On Mon, 29 Oct 2007, Jon Elson wrote:
The idea is that 100 mbit/sec ethernet is fast. What other
RS485 device do you have that runs that fast?
Of course a RS-485 link can have smaller packets, and may actually have much
better real time performance. (a single 10 MBps RS-485 link will have
-
From: Jon Elson [EMAIL PROTECTED]
To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net
Sent: Monday, October 29, 2007 7:44 PM
Subject: Re: [Emc-users] Ethernet I/O
Erik Christiansen wrote:
On Fri, Oct 26, 2007 at 08:37:47PM -0500, Javid Butler wrote:
The real problem
I really think all of the thread raised issues have been addressed by
Ethercat:
Umm, no... As master, no problem but slaves will be expensive:
Ethercat slaves require either custom proprietry hardware or proprietary IP
You can not use a generic ucontroller with Ethernet as a EtherCat slave.
Umm, no... As master, no problem but slaves will be expensive:
Ethercat slaves require either custom proprietry hardware or proprietary
IP
Hmm, unfortunately I can't argue there.. been trying to find some prices for
a slave chip.
I found some products, but no prices anywhere:
- beckhoff
PROTECTED] Behalf Of Peter C.
Wallace
Sent: Monday, October 29, 2007 2:16 PM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Ethernet I/O
On Mon, 29 Oct 2007, Alex Joni wrote:
Date: Mon, 29 Oct 2007 21:00:22 +0200
From: Alex Joni [EMAIL PROTECTED]
Reply-To: Enhanced Machine
Peter C. Wallace wrote:
On Mon, 29 Oct 2007, Jon Elson wrote:
The idea is that 100 mbit/sec ethernet is fast. What other
RS485 device do you have that runs that fast?
Of course a RS-485 link can have smaller packets, and may actually have much
better real time performance. (a single 10
Kenneth Lerman wrote:
Jon,
You suggest that the PC would request the registers from the IO board and
the IO board would respond with the requested registers. How much delay,
jitter, latency,... is acceptable?
Darn good question. I know the jitter on when the current
parport interface
Javid Butler wrote:
Jon-
The Silicon Labs chip is not a typical 8051. You are correct about a
standard 8051, but this chip is more of an 8051 core running at 50 or 100
MHz. They may have a version with an Ethernet MAC and DMA as well.
Which ARM7 are you looking at? Atmel has some good
Jon Elson wrote:
Stephen Wille Padnos wrote:
You can't use any old
topology with RTNet. RTNet is a TDMA scheme - each device gets a time
slot in which it may transmit. This eliminates collisions, which are
the main cause of timing jitter on ethernet.
Well, after some more reading of the
-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Jon Elson
Sent: Sunday, October 28, 2007 4:43 PM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Ethernet I/O
Jon Elson wrote:
Stephen Wille Padnos wrote:
You can't use any old
topology with RTNet. RTNet is a TDMA
For me, the issue of RTnet is irrelevant. I would, instead, just want to
use
the Linux driver. If we can get that to generate and receive ethernet
frames
in real time, we are in business.
Then we could let the PC be a master and any peripherals be slaves. In the
case of the UPC board,
Javid Butler wrote:
For me, the issue of RTnet is irrelevant. I would, instead, just want to
use
the Linux driver. If we can get that to generate and receive ethernet
frames
in real time, we are in business.
Then we could let the PC be a master and any peripherals be slaves. In the
case of the
Could you provide an example of a servo motor with feedback?
I will try, but all my machines are stepper driven, so while I think I
understand the concept of a servo drive I've never tuned one or worked with
it directly. Feel free to correct any misunderstandings. I'm using arbitrary
Kenneth Lerman wrote:
For me, the issue of RTnet is irrelevant. I would, instead, just want to use
the Linux driver. If we can get that to generate and receive ethernet frames
in real time, we are in business.
Well, that's the problem, it is NOT real time code. I don't
know how far it is
Jon Elson wrote:
Kenneth Lerman wrote:
For me, the issue of RTnet is irrelevant. I would, instead, just want to use
the Linux driver. If we can get that to generate and receive ethernet frames
in real time, we are in business.
Well, that's the problem, it is NOT real time code. I don't
Stephen Wille Padnos wrote:
Jon Elson wrote:
Kenneth Lerman wrote:
For me, the issue of RTnet is irrelevant. I would, instead, just want to use
the Linux driver. If we can get that to generate and receive ethernet frames
in real time, we are in business.
Well,
Stephen Wille Padnos wrote:
An ethernet segment must be either RT or not RT. If you connect a
non-RTnet device to a hub/switch with RT devices on it, all bets are
off.
Yes, clearly you take a certain risk if you tie the ethernet
segment to the rest of the local net. Even with a router in
Kirk Wallace wrote:
Okay, now I know. Thanks. I'm looking forward to seeing what happens
with this.
Don't hold your breath, I am still not too clear on whether this
will work without massive modification of EMC2, and how it uses
rtai.
I have been thinking, that it would be nice to move some
I've done a bit of programming and circuit board design with Silicon
Laboratories 8051 chips. They have an ethernet developers kit complete
with schematics.
http://www.silabs.com/tgwWebApp/public/web_content/products/Microcontrollers/en/EthernetDK.htm
I have not priced the components, but a
Brian Michalk wrote:
I've done a bit of programming and circuit board design with Silicon
Laboratories 8051 chips. They have an ethernet developers kit complete
with schematics.
http://www.silabs.com/tgwWebApp/public/web_content/products/Microcontrollers/en/EthernetDK.htm
I have not
One concern is using a standard that will soon be obsolete. The
parallel port has mostly been replaced by usb; ISA has been
replaced by PCI, which has been replaced by PCI-X.
Even the fastest ethernet is still backwards compatible with the
original standard.
Another nice thing is cost and
,
Alex Joni
- Original Message -
From: Mark Pictor [EMAIL PROTECTED]
To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net
Sent: Friday, October 26, 2007 9:18 PM
Subject: Re: [Emc-users] Ethernet I/O
One concern is using a standard that will soon be obsolete. The
parallel
Kirk Wallace wrote:
There is some discussion on another thread about using Ethernet for EMC
I/O. I can see that there is the appeal of plentiful and cheap hardware
available with Ethernet, but there seems to be a fair amount of hacking
needed to make it work. For my education, why not use a
Jon Elson wrote:
Kirk Wallace wrote:
There is some discussion on another thread about using Ethernet for EMC
I/O. I can see that there is the appeal of plentiful and cheap hardware
available with Ethernet, but there seems to be a fair amount of hacking
needed to make it work. For my
On Fri, 2007-10-26 at 19:48 -0500, Jon Elson wrote:
Kirk Wallace wrote:
There is some discussion on another thread about using Ethernet for EMC
I/O. I can see that there is the appeal of plentiful and cheap hardware
... snip
that out. That just won't work for the way the hal_ppmc.c
driver
: Friday, October 26, 2007 11:53 AM
Subject: [Emc-users] Ethernet I/O
There is some discussion on another thread about using Ethernet for EMC
I/O. I can see that there is the appeal of plentiful and cheap hardware
available with Ethernet, but there seems to be a fair amount of hacking
needed
On Fri, 2007-10-26 at 21:04 -0400, Stephen Wille Padnos wrote:
Jon Elson wrote:
Kirk Wallace wrote:
There is some discussion on another thread about using Ethernet for EMC
I/O. I can see that there is the appeal of plentiful and cheap hardware
... snip
keep excess net traffic off
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