Latency question

More
12 Mar 2017 23:22 - 12 Mar 2017 23:27 #89493 by beltramidave
beltramidave created the topic: Latency question
I have been getting an error "Unexpected real time delay" upon startup of Linuxcnc, forever. I have read about the Latency testing and have done it several times, but I never changed any parameters.

My Base Thread = 100000 in my .ini file.

I just ran the latency test and it (Base Thread) came back at 27540. Can anyone tell me what my Base Thread should be in the .ini file based on this latest test.

Thanks
Last Edit: 12 Mar 2017 23:27 by beltramidave.
More
13 Mar 2017 09:09 #89503 by rodw
rodw replied the topic: Latency question
Maybe try playing with the two .INI settings below. Pretty sure the comments were added by PCNCCONF but this is stright out of my .INI file and increasing them solved problems for me on a Mesa 7i76e
# The values below should be 25% larger than MAX_VELOCITY and MAX_ACCELERATION
# If using BACKLASH compensation STEPGEN_MAXACCEL should be 100% larger.
STEPGEN_MAXVEL = 700
STEPGEN_MAXACCEL = 2000
More
13 Mar 2017 13:01 #89512 by beltramidave
beltramidave replied the topic: Latency question
Rodw,

Here is a snippet of my .ini file settings:

[TRAJ]
AXES = 3
COORDINATES = X Y Z
LINEAR_UNITS = inch
ANGULAR_UNITS = degree
CYCLE_TIME = 0.010
DEFAULT_VELOCITY = 5.0
MAX_LINEAR_VELOCITY = 5
[EMCIO]
EMCIO = io
CYCLE_TIME = 0.100
TOOL_TABLE = tool.tbl

[AXIS_0]
TYPE = LINEAR
HOME = 0.0
MAX_VELOCITY = 5.0
MAX_ACCELERATION = 10.0
STEPGEN_MAXACCEL = 15.0
SCALE = 1600
FERROR = 0.08
MIN_FERROR = 0.05
MIN_LIMIT = -0.065
MAX_LIMIT = 25.625
HOME_OFFSET = -.125
HOME_SEARCH_VEL = -0.5
HOME_LATCH_VEL = -0.02
HOME_IGNORE_LIMITS = YES
HOME_SEQUENCE = 1
HOME_FINAL_VEL = .1
More
14 Mar 2017 17:12 #89611 by andypugh
andypugh replied the topic: Latency question

beltramidave wrote: I just ran the latency test and it (Base Thread) came back at 27540. Can anyone tell me what my Base Thread should be in the .ini file based on this latest test.


What is it now?

How many steps per second do you need at max speed?
More
14 Mar 2017 18:39 #89624 by beltramidave
beltramidave replied the topic: Latency question
[EMCMOT]
EMCMOT = motmod
COMM_TIMEOUT = 1.0
COMM_WAIT = 0.010
BASE_PERIOD = 100000
SERVO_PERIOD = 1000000

This is what the machine control came set up with. Right now my max rapid speed is 300ipm.

Thanks,
Dave
More
14 Mar 2017 22:24 #89634 by andypugh
andypugh replied the topic: Latency question
If you are getting over-runs at 100,000 then I don't know what to suggest.
More
16 Mar 2017 16:33 #89750 by beltramidave
beltramidave replied the topic: Latency question
There has to be an answer to this. I just reran the latency test after playing with some video settings and the highest I saw the base thread go was around 14500 and most of the time it was below 10000 EXCEPT when I opened some picture files and then it would spike above 200,000. I believe that it must have something to do with the video card (which is Nvidea).

Thought maybe I had fixed something as the first time I opened Linuxcnc, I didn't get any error, so i shut it down and restarted Linuxcnc again and the error message came back.

This is a dual boot machine and I had to go back into Windows XP to change anything. I never use Windows and I am not connected to internet with this machine. Also when running a toolpath, I am not doing anything else with the PC.

I am definitely not good with Ubuntu and getting around in it, so if there is something I can check, please tell me how (exactly).

Thanks for your help
More
16 Mar 2017 16:48 #89754 by PCW
PCW replied the topic: Latency question
Did you see this?

wiki.linuxcnc.org/cgi-bin/wiki.pl?Troubl...d_ATI_graphics_cards

The Nvidia driver has known issues with latency
More
16 Mar 2017 17:00 - 16 Mar 2017 17:25 #89756 by beltramidave
beltramidave replied the topic: Latency question


Yes I did, but not sure what to do...
Attachments:
Last Edit: 16 Mar 2017 17:25 by beltramidave. Reason: added latency pic
Time to create page: 0.091 seconds
Powered by Kunena Forum