2.6 release

Update,
I have built a linear sled out of parts, for testing stepper torque and drivers now.
The sled details are, 20 inches of travel and is attached to a roller chain drive off the stepper motor.
I made it very coarse in step scale compared to say a mill, I didnt want to use heavy weights for testing.
It looks to still be very accurate as it should be, even at the low pulse count per inch that its using now.

I created a new test machine in stepper config and changed Z to match the new settings, X,Y,A are still at there original settings and nothing has been changed in any way other than Z to match the new steps per inch and latency to 20k just to rule that out.

With a ruler the stepper looks like it is not losing any steps while attached to the sled, the digital DRO still is reading an error on Z only. When I boot into win7 and use mach3 with the same pc, with Z changed to match the sled stepper scale the DRO readout matches the commanded output from mach3.

Here is another thing I noticed which maybe related or not.
First setup I made in stepper config was XYZ and latency of 20k, up from the original 5k which worked perfect in 2.5.4 release and older version of 2.6 / 12.04 ubuntu. It started without errors other than the DRO on Z not matching linuxcnc DRO.

Second new setup I added A for XYZA stepper config , now the first time I start linuxcnc, it will give me a realtime error shortly after starting, so I shutdown linuxcnc, then restart linuxcnc and never see the error again while testing , still see the DRO error on the DRO Z, the stepper measurement on the ruler looks like no steps are lost moving the sled 4-6 inches back and forth, I just cant understand why the DRO readout is acting up only in 2.6.0 pre and should I be worried about it ?

This maybe not related ? but heres another post from someone else experiencing a realtime problem Charting servo period clock jitter while running

Yes

In 2.5.4 Ive ran it for hours and always would go back to 0 and both matched, in earlier 2.6 it also matched.

Right, the DRO numbers continue growing a small amount the more I run Z back and forth, linuxcnc returns to 0 as commanded and it looks like the stepper motor is not losing or adding steps.
The DRO is attached to, electrically and physically to the bob and reads stepper pulses directly.

In my stepconfig-stepper base information Ive left all settings at default , this is the only part I havent tried changing.
driver type = other
step time = 100
step space = 100
dir hold = 100
dir setup = 20k
jitter = 20k , originally = 5k

This was where my settings have been since 2.5.4

Next I may use a scope and watch pulses...

There is one redeeming quality to having a redundant DRO, mach3 thinks 1 inch is 25.384mm where as linuxcnc sees 1 inch as 25.400mm , must be something like ms, 1meg is not 1024k.

I will try timing and see if that clears up my problem.

One other thing Im wondering is, can I install ubuntu 12.04 precise without installing the 12.04.4 LTS first.
Just trying to avoid the auto update, which sometimes resets grub2 back to LTS.
Guessing this may change in the release version.

driver type = other
step time = 100
step space = 100
dir hold = 100
dir setup = 20k

That is what you input, but what did stepconf actually output?

Very often it is something like this where the steplen is set by the parport reset time


setp stepgen.0.position-scale [AXIS_0]SCALE
setp stepgen.0.steplen 1
setp stepgen.0.stepspace 0
setp stepgen.0.dirhold 70000
setp stepgen.0.dirsetup 70000

What is the parport reset time set to? 5000 seems typical.

Also check the dir hold figure that was output, 100ns seems very low, most controllers need much more than that
wiki.linuxcnc.org/cgi-bin/wiki.pl?Stepper_Drive_Timing

Otherwise this is properly weird

setp stepgen.0.position-scale [AXIS_0]SCALE
setp stepgen.0.steplen 1
setp stepgen.0.stepspace 0
setp stepgen.0.dirhold 10100
setp stepgen.0.dirsetup 30000

axis 0 to 3 all the same numbers

setp parport.0.reset - time 100 (only one I see in hal)

100 is max in stepconfig for "other"
Tried to manually set step time, space and hold to a higher than 100 and it resets to 100, which was the max stepconfig lets me set them to.
Ive changed setting in the ini file before but never touched hal settings, Ill look it over and see it I can find what needs changed.

---

went into hal and changed
setp parport.0.reset - time 5000
Z now matches the DRO

I believe the wireless network card is eating some of my cycle time, now that it works in ubuntu 12.04 , didnt run in 10.04 , and thats why I had to raise the latency up, but I can turn it off when not needed.

Thanks, I believe mystery solved with a little manual editing.

I tried 1000 and then 500, both run without the DRO error.

Now all thats left is to find a way to compile an install of precise without RTA first and Ill be set

Thanks again