EMC configuration (?) issues

[JBasDiez]

Hi all,
I have installed Ubuntu 6.0.6 and EMC2 in my Dell C610 laptop (1Ghz, Pentium III). It uses dual boot and at the moment every thing is apparently working perfect on the screen, including graphic simulation etc... until I connect it to my mill machine. The problem is that the step motors do not operate "fine". They produce a lot of rough noise and looses steps no matter what speeds and accelerations I use (worst with higher speeds).

I initially suffered the "MSI board effect" resulting in periodic latency figures close to 100,000 nSec. This was corrected following directions in the web page and now latency figures are rock stable around 6,000 nSec at idle going temporaly up to close 30,000 when I force the system with other applications demanding higher CPU usage. As far as I understand, these are aceptable results.

I have used both Stepconf as well as manual configuration without being able to resolve the problem so far. I use Geko G201 microstep motor drives and as a reference I would mention that the machine has been operated by TurboCNC for long time (and still is) without any issue, so I do not think there is any hardware relationship with the problem.

I like EMC2 and I'm most interested in resolving the problem but right now I'm completely blocked.

Any suggestions?

Thanks in advance.
Jesus

[unterhaus]

are you using metric units? It may be an issue of input/output scale. There is also a hold time problem with geckos that can cause this problem

[JBasDiez]

Originally Posted by unterhaus are you using metric units? It may be an issue of input/output scale. There is also a hold time problem with geckos that can cause this problem

Yes, I'm using metric units, but I don't think there is a scale issue as actual distances in the machine are correct. The Gecko drives configuration could be a more probable reason. Any idea about recommended settings?. I have been testing some without success.
Thanks.

[acondit]

Originally Posted by JBasDiez Yes, I'm using metric units, but I don't think there is a scale issue as actual distances in the machine are correct. The Gecko drives configuration could be a more probable reason. Any idea about recommended settings?. I have been testing some without success. Thanks.

Jesus,

Did you solve your problems yet? It turns out that the original release of stepconf was majorly broken. They have just released a bug fix emc2_2.2.2. I would suggest trying it. I also saw another thread http://www.cnczone.com/forums/showth...286#post374286 that had suggested settings for some geckos.

Alan

[Wolfesmetalfab]

corrected following directions on the webpage? Which webpage, I am searching trying to find out what to do to fix latency spikes, software or hardware, i dont care i will fix it.

[chester88]

Have you looked at the EMC wiki?

http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl

[Wolfesmetalfab]

i did now, and have been trying things, disable onboard audio, disable 1394, disable onboard lan...

The computer I am running is a HP Pavilion a220n that has AMD Athlon 2600+ (stock) w/ better heat sink and fan, 1gb ram, ASUS GeForce 4 Ti4200-8x 128mb AGP , 120 seagate HD 1mb buffer (stock), Sony Dual RW DVD drive, cd-rw drive (stock). 300watt PSU.

I have a PCI wireless desktop card in for wifi. I also have a PCI tv card and an old modem card, may try removing them, as I dont use them anymore anyways. Edit:removed now, will retest.

I can start latency-test, and i have 4 instances of glxgears running, and I am running 19591 max Base after approx 15min, but i have had spikes take it up to 70000 and above 100000 when browsing internet, playing solitare, music, moving around windows, etc. in previous tests.

Bios doesn't seem to have settings for power saving, just disabling onboard video, it has options PCI or AGP/Onboard, as I have it set on the second for my card.

how much is too much to expect not to make spikes? Opening programs do it? Hard Drive not sufficient buffer, specs? Ram speeds the culprit?

Still after typing, thinking, editing, etc. Still at 19591 max base jitter

any thoughts?

[Wolfesmetalfab]

after supper, and waking the display, I found 35000, and then went to check power management preferences, and spiked to 47000, and now its 68000.

very aggravating, I thought this pc would be a prime candidate, i need to figure out what's causing it.

[chester88]

Did you read this?
http://wiki.linuxcnc.org/cgi-bin/emc...roubleShooting

The video card, SMI, and ACPI are the biggest culprits but sometimes things like the cd drive will wreck real time. Take out everything you don't need. Turn off options in the BIOS you don't need/want and maybe change to a cheap PCI video card.

[Wolfesmetalfab]

I saw it and got scared away by all the mumbo jumbo being new to Linux as well. LOL The SMI shouldnt be an issue should it? Since I am AMD, and not Intel. That video card hasn't stirred any red flags I have seen either. I have my Machine PC dual booted with xp and ubuntu, and played with mach 3 on xp, and did the driver test, and it tested out great in mach, Excellent actually. I may be leaning toward that route as the emc2 and latency crap has gotten me very aggravated, and mach 3 seamed to work flawlessly, setting up simulation and running tool path, I use autocad already, and lazycam (maybe sheetcam in the future) seems easy and quick, and then loading to mach 3. There are so very many extra options and stuff i probably will never use, but its there if i need it.

[acondit]

If there are performance issues with your cpu they will still be there with Mach, you may not see them but they will be there. With EMC2 we try to eliminate the problems rather than hiding them.

Alan

[margni74]

What value are you using for the latency? Max Jitter? Which thread? Im trying to determine these numbers too and am a bit lost