machinekit
Joint following error on larger file
Hi there! I most certainly don't know this is the right place for it, if it isn't, I apologize in advance. I am running machinekit remote, mkwrapper as DISPLAY, along with cetus interface as remote interface, on a BeagleBone Green, rt-preempt on a 4.4 kernel, most recent (as of 10/2/2018) apt-get available machinekit release, latest machinekit client release. I am having issue with joint following errors. It happens if I go any further on a given long ngc file. If I reduce a lot the feed rate (from 1800 mm/min to 600 mm/m), it doesn't happen. Tried varying servo thread period and reducing stepgen period, without success. If I execute the exact same a remote X session over ssh and the axis front end, I get no problems. Is there a way for me to debug this issue any further? Thanks! Paulo Sherring.
Can you please try to monitor the CPU load using top or htop. Is there any significant difference between Axis and mkwrapper? Also please make sure CYCLE_TIME time is equal in both setups.
I'm also seeing joint following errors when using Cetus & mkwrapper, but file size does not seem to matter. Axis works fine, I have run a few programs with that with no issues. In my case CYCLE_TIME is the same. When I get a chance later I will report on CPU usage.
I am running BBB+CRAMPS+machinekit 2018-12-10 and am having strange following errors when I use the mkwrapper as a display. I can run the same file with ssh + X using AXIS gui with no issue.
I am also getting unexpected behavior of the limit switches, where the Cetus GUI indicates they are asserted when the are not.
When I monitor the CPU with htop, soon after I start execution of my *.ngc file, the CPU load spikes to 100% and I get following errors. The following errors have happened on all axes (X,Y,Z) on different trials. This is a repeatable issue.
Also, I am using open loop steppers so the following error is confusing to me...
Please let me know if I can help debug.
Scott
Hey there! I was finally able to get back at this. I also found the CPU spike after the "play" button is pressed and I still have the same issue: with longer files and higher speeds, I get the joint following issue. I really would like to get this to work as I don't like at all using AXIS over SSH :( If there is anything you would like me to try, please advise :) Paulo Sherring
Hey, I guess I found the offending stuff! Try this out: On your python starting script, try changing the mklauncher debug level from 5 to 1: launcher.set_debug_level(5) --- launcher.set_debug_level(1) +++
I found that journald spiked hard when debug level was high. It all works here! :D It is very likely that this issue is platform dependent, since BBB uses slow access memory (i.e. sd card or even embedded flash). @presslab-us and @scottnortman : if you guys could try this out, it would be great to have a more consistent solution :) Paulo Sherring.