Bridgeport Retrofit - keyboard input delays noted

A year or so ago I converted an Interact Mk1 to LinuxCNC using a Foxconn pc (Atom mb)and Mesa 5i25/7i77. Currently I am on the Ubuntu 10.04 with 2.6.xyz (from master-rt yesterday) using the AXIS screen. When I initially completed the retrofit, I noticed some funnies associated with keyboard entry. I have been able to ignore them successfully for a while but now thought it time to dig this out. I have plans to change my router from Mach3 to LinuxCNC and to retrofit a 13x40 lathe next. I have the computers for both of these but more on that in a bit.

The symptoms are as follows and are all intermittent but repeatable:

1) delay of +/-10seconds switching from Manual to MDI and back. (using keyboard, using mouse on screen, using joystick emulation of keyboard)
2) delay after a Touchoff - click the touchoff icon or keyboard "end". enter a value. hit enter or icon to complete. then wait several seconds. again +/-10.
3) delay using MDI entry. type valid command on command line and hit enter. I notice a delay of 10 or so seconds before the command jumps to the history window but the machine doesn't move. imaging changing a tool, thinking you are applying a tool offset and not notice that it never happened. gets ugly. This is really the symptom that causes me to investigate the cause.

Further, I have never noticed any problems with the machine running a program. I have cut many parts with no issue. It is only when I use Manual or MDI mode.

Another symptom that may or may not be related. I have installed a ShuttlePro using HIDCOMP/HIDCONFIG and some custom hal code to preform continuous and incremental jog functions. Most of the time all works fine but there are the occasions where the incremental (hardcoded to 0.0005" steps on the inner wheel) inputs will be ignored. I have used HAL config monitor to verify that the inputs from the shuttle are seen on the input pins so I believe the problem is similar to the above symptions. Sometimes the dang thing just ignores input in Man mode.

Other considerations for the gurus....

1) I have the same make model computer and LinuxCNC code (similar hal with ShuttlePro features) installed on a 9x20 lathe using steppers (no MESA hardware). I converted this from a MACH3 platform to LinuxCNC. I have seen no "delay"s noted above on this machine.

2) I have swapped out the Foxconn pc with an old Dell 260 that I had laying around. 2.2G Intel P4 so it is about 2x the horsepower as the Foxconn. The symptoms are still evident but the delays are nowhere near as long. I can live with this PC change but would rather not.

3) I have a friend who retrofitted an American Way lathe using the same hardware (fox, mesa combo) and level of code. The symptoms are identical on that machine too.

I have 2 more of these Foxconn computers sitting on the shelf for my 2 new retrofits so I would like to protect that investment by solving this delay problem.

One last thing that I noted, while attempting to pin down the symptoms and conditions I ran the system monitor and noticed almost 100% CPU util while running EMC with the machine in motion. 75% when sitting idle. Also when the "delay" happens, Note that the CPU drops to about 10% or so during the 10second delay. Makes you scratch your head.

I can provide greater technical detail so feel free to ask for specifics. Any help is appreciated.

Mark

you do not mention the board or spec of this pc .

replace the pc with better spec machine .. dell pc's realy are no better ,,.
also make sure you have at least 2gig of memory available .

also keep away from pc's with onboard graphics

fitting a solidstate drive may help if these motherboards are capable of sata drives

Atom mb 45ctp/45ctd
bios ver P06
Mem 1G
CPU 230 @1.6Ghz
hyper threading is disabled
spread spectrum is disabled
smart fan is disabled
internal graphics PCT/IGD

Latency
max jitter around 7800 servo thread and 9300 base thread
max interval servo 998436 base 33120

system monitor shows memory consumption is well under 200MB
don't believe this is hd io bound.

Thanks,
Mark

When you have linuxcnc running, can you open a terminal window and type:

halcmd show all > allhal.txt

and post the results here?

This should help narrow down "where the time goes"

1 gig of memory is low for reliable operations try 2gig
also try fitting a seperate graphics card and disable on board ..

i'll bet it's related to graphics , but as PCW says see what results you get ..

i'd also try moving the 5i25 to another slot if you can

Thanks. Here you go.

Mark

There is only a single PCI slot on the MB so an external graphics card is not an option nor is moving the 5i25 unfortunately.

Mark

OK adding (rough estimate) all the times in the servo thread I get about 77 uSec
total which should be fine for a 1 KHz servo thread. So it does not look like the RT part of
LinuxCNC is the problem. Maybe something with the GUI/memory etc

Thanks. I would have thought that if this were a real time problem I would have had problems with the operation of the machine under control. The machine works fine.

Wondering what the next step is.

As mentioned above, I don't have extra slots so I can't add separate video card nor move the 5i25. I also don't have a 2G simm laying around to try although I tend to think that isn't it either unless the system monitor is not accurate. I was running the machine in motion, connected to the Internet and had the sys monitor all running simultaneously (not something I ever do but for the sake of testing) and the memory consumption never exceed 235MB. I was also hammering on the keyboard while this was all going on.

Anybody else experience this type of delay?

Any other ideas?

Mark

Does "top" give any clues as to where the CPU cycles are going?