Re: [Emc-users] emc2 2.2.6 hostmot2 stepgen bug workaround
Sebastian, et al, The good news is, the patch seems to work. The bad news is that at other than very slow speeds (25-50 IPM) I keep getting following errors. I have played with the MAX_ACCELERATION and STEPGEN_MAXACCEL (which I suspect does not apply with Hostmot2), but that seems to have almost no effect. What does have an effect is the setting of the Servo period in the ini file. If I set it for 1ms, I get following errors almost no matter how slow I try to move the axis. If I drop it to 100 microsecs then I can get up to 25 or so IPM, and at 66 microseconds (the fastest I can set the servo loop on this board) to about 55 IPM. Is it possible I am not doing the position feedback properly. This is what I have for position feedback in my HAL file: net Xpos-fb hm2_5i20.0.stepgen.00.position-fb = axis.0.motor-pos-fb net Ypos-fb hm2_5i20.0.stepgen.01.position-fb = axis.1.motor-pos-fb Alternately, do I have to set a deadband as in a servo configuration? I tried setting the deadband to 0.002 which should be just larger than one micro-step for the motor. It did not seem to have any effect either. Thanks, Eric EMC2 2.2.6 included the new hostmot2 device driver, with support for the Mesa 5i20 and 7i43 boards. Unfortunately, due to a bug in the driver, stepgen didn't work on the 5i20 (though it works on the 7i43). The problem has been fixed in TRUNK and in the 2.2 branch, but that only helps people who are compiling from source. Users who install emc2 via the debian package (.deb) can get stepgen working on 2.2.6 by following this recipe: 1. Add enable_raw to the load-time config string for the 5i20. 2. Set hm2_5i20.0.raw.write_address to 0x2900. 3. Set hm2_5i20.0.raw.write_data to -1. 4. Set hm2_5i20.0.raw.write_strobe to 1. When the hm2_5i20.0.write function next runs, the steppers will start working. - This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100url=/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] emc2 2.2.6 hostmot2 stepgen bug workaround
Eric H. Johnson wrote: The good news is, the patch seems to work. The bad news is that at other than very slow speeds (25-50 IPM) I keep getting following errors. I have played with the MAX_ACCELERATION and STEPGEN_MAXACCEL (which I suspect does not apply with Hostmot2), but that seems to have almost no effect. The hostmot2 stepgen driver does not yet support maxaccel or maxvel. The stepgen code is very simplistic, I'm planning to fix it up and make it feature-complete (for step/dir and up/down) in the next few days. -- Sebastian Kuzminsky Computer Science for life, that's my direction Instead of b-balls, my homies throw exceptions -- MC Plus+ - This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100url=/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] emc2 2.2.6 hostmot2 stepgen bug workaround
Sebastian, Any idea what is causing the following errors? I suspect it is the feedback, because as I make the servo period faster, I can then have the motor go faster. I am probably missing something obvious, but it seems like it needs a dead band or something like that, except I tried setting a dead band and that doesn't work. Any ideas? Regards, Eric The hostmot2 stepgen driver does not yet support maxaccel or maxvel. The stepgen code is very simplistic, I'm planning to fix it up and make it feature-complete (for step/dir and up/down) in the next few days. - This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100url=/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] emc2 2.2.6 hostmot2 stepgen bug workaround
Sebastian wrote: The hostmot2 stepgen driver does not yet support maxaccel or maxvel. The stepgen code is very simplistic, I'm planning to fix it up and make it feature-complete (for step/dir and up/down) in the next few days. Eric H. Johnson wrote: Any idea what is causing the following errors? I suspect it is the feedback, because as I make the servo period faster, I can then have the motor go faster. I am probably missing something obvious, but it seems like it needs a dead band or something like that, except I tried setting a dead band and that doesn't work. Any ideas? Regards, Eric Following errors happen when the position feedback fails to track the command within a tolerance. That tolerance is specified in your ini file - what values do you have? Seb has acknowledged that there are issues and is working on it. Further speculation, especially without hard data, is pointless. If you are curious about what is going on, break out halscope and take a look. The command, the feedback, the error, and the error limits are all available as HAL pins or parameters, and there is also a faulted parameter that can be used to trigger the scope. Regards, John Kasunich - This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100url=/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] emc2 2.2.6 hostmot2 stepgen bug workaround
John, I think I got it, at least it is working much better now. I was trying to adjust FERROR, and when that did not work, thought DEADBAND or something like that might apply. What I did not adjust was MIN_FERROR, which the doc says applies only for very slow speeds. I was not having a problem at very slow speeds, only when I tried to speed up. But increasing MIN_FERROR now has it basically working (my accel and max velocity are still set low so I still have a little tuning to do). I guess MIN_FERROR doesn't do quite what I thought it did. Regards, Eric Following errors happen when the position feedback fails to track the command within a tolerance. That tolerance is specified in your ini file - what values do you have? Seb has acknowledged that there are issues and is working on it. Further speculation, especially without hard data, is pointless. If you are curious about what is going on, break out halscope and take a look. The command, the feedback, the error, and the error limits are all available as HAL pins or parameters, and there is also a faulted parameter that can be used to trigger the scope. - This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100url=/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] emc2 2.2.6 hostmot2 stepgen bug workaround
Sebastian, Thanks. I will test it with hardware on Monday. Please see post in emc-developers. Regards, Eric EMC2 2.2.6 included the new hostmot2 device driver, with support for the Mesa 5i20 and 7i43 boards. Unfortunately, due to a bug in the driver, stepgen didn't work on the 5i20 (though it works on the 7i43). The problem has been fixed in TRUNK and in the 2.2 branch, but that only helps people who are compiling from source. Users who install emc2 via the debian package (.deb) can get stepgen working on 2.2.6 by following this recipe: 1. Add enable_raw to the load-time config string for the 5i20. 2. Set hm2_5i20.0.raw.write_address to 0x2900. 3. Set hm2_5i20.0.raw.write_data to -1. 4. Set hm2_5i20.0.raw.write_strobe to 1. When the hm2_5i20.0.write function next runs, the steppers will start working. - This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100url=/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
