Hi,
what do you mean by enumerate a few times? USB enumeration
takes place only once.
I don't think we need to discuss the basics of USB as i have built several
USB devices and have also written kernel drivers and libusb based user space
drivers for linux, windows and macos. So this all isn't a
Hello Till,
I would love to have a USB interface to EMC as well. I only have a laptop
and it only has USB ports.
I've spent some time learning about USB/EMC/RTAI and have thought of 3
possible ways of making EMC work with a USB device. I'm still relatively
new to this (especially EMC RTAI)
The place I see for USB in EMC is to replace the printer port solutions. The
advantage of USB would be that it is available on most machines, including
laptops, while printer ports are becoming less available.
I understand that it is not what you had in mind.
Ken
[EMAIL PROTECTED]
Mark Kenny
Kenneth... USB does not support realtime actions, so it is no direct
replacement.
But I still see some advantages in the realtime core. And that is
precise timing.
Easiest way how to find out how EMC works is to install it and find
out. Maybe only running live CD might help. Source codes and
Mario,
It is my understanding that usb supports isochronous transfers with
guaranteed access to usb bandwidth and bounded latency. That would clearly
support realtime actions.
The bandwidth is clearly high enough to support our requirements. It is not
clear (to me) whether usb would meet our
Yes, you are right and it is nice that you point to the isochronous
transfers, but as a Microsoft standard, USB has had poor latency. It
is not known to me how are any recent latency tests...
On 4/23/07, Kenneth Lerman [EMAIL PROTECTED] wrote:
Mario,
It is my understanding that usb supports
Not quite correct.
There are various parts that compose what we call EMC.
We have : 1. interpreter (userlevel), 2. task controller (userlevel), 3. io
controller (userlevel, although using HAL), 4. GUI (userlevel), 5. motion
controller (realtime).
#1 and #2 are actually linked together, but
Alex Joni wrote:
Not quite correct.
There are various parts that compose what we call EMC.
We have : 1. interpreter (userlevel), 2. task controller (userlevel), 3. io
controller (userlevel, although using HAL), 4. GUI (userlevel), 5. motion
controller (realtime).
#1 and #2 are actually
John,
When I think of that approach, I don't think rewrite; I think port. Of
course, depending on what processor the USB device uses, that might range
from difficult, to impossible.
If the USB device has floating point and is reasonably fast, it should be
doable without much rewrite. Without
Like someone said here before, the bandwidth of USB is certainly enough
for (open loop) motor control of as many axes as one can imagine, but
the latency might not be good enough for real time feedback loops (1kHz
loop rate is what most people use I think).
One 'device-on-a-rope' at least I
Kenneth Lerman wrote:
John,
When I think of that approach, I don't think rewrite; I think port. Of
course, depending on what processor the USB device uses, that might range
from difficult, to impossible.
If the USB device has floating point and is reasonably fast, it should be
doable
Anders Wallin wrote:
I'm now building a servo system around the m5i20 but I'm having to use
some amount of discrete logic etc. to accommodate the encoders, servo
drives, etc. If I would do it all again I would put more things in
software(FPGA blocks) and less in hardware. Inexpensive
One 'device-on-a-rope' at least I would find interesting would be an
to be honest, if one really wants a device-on-a-rope, and wants
to use EMC, then they should build a small linux system to be at
the end of the rope. use something like the gumstix board, or an
efika
mario wrote:
Yeah, it seems like the ultimate USB end-device for EMC would be still
a PowerPC processor running realtime linux. heh. So we ended up just
where we started.
well, not really -- if part of the goal is to make a small box
that can be plugged into any PC and made to work in a
I didn't think of that approach. But it basically means discarding
EMC's motion controller and writing a new one inside the USB device.
The EMC motion controller (including trajectory planner) is the result
of years of work, and would not be trivial to replicate.
And it isn't what i
Till Harbaum wrote:
Hi,
isochronous transfers are imho currently not supported by libusb. So it needs
a new kernel driver (which isn't that much of a problem, agreed) and wouldn't
be portable (also not a problem since emc isn't portable at all). So yes, this
would be possible.
On the
Hello,
Has anyone looked at the realtime USB host/core driver port? I would think
this would be ideal, as everything would then be USB.
Garrett.
-
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the
This says it include the emc trajectory planner.
(sounds like it uses the emc planner as a pre-proccessor. Then sent to the
pod) Just scanned over it.
sam
- Original Message -
From: Alex Joni [EMAIL PROTECTED]
To: EMC developers emc-developers@lists.sourceforge.net
Sent: Monday, April
On Monday 23 April 2007, sam sokolik wrote:
sorry - forgot the link. Duh
http://ncpod.oemtech.com/
sam
Gee, Sam, you would think they would like to sell it, but I looked at every
submenu there and all I could find was a limited performance beta test for a
big buck. Definitely no hard sell
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