Hello, folks! After my previous mail to the list I was encouraged by John Thornton to simplify thc.comp, and so I did. I removed several functions, including the idea that Z position is reported back without the offset added by thc. I would like thc to be as simple as possible - compare actual thc.volts and thc.volts-requested and then issue changes for Z position, if necessary. And that is it. I find it more convenient, if EMC receives back actual Z position, not the (actual - offset). And I find it more convenient, if that offset is not removed, once EMC knows the actual Z position. But the problem with this concept is that now I am stuck with a fundamental question - how to avoid following error on Z axis.
The thing is that THC module "sits" between axis.3.motor-pos-cmd and stepgen.3.position-cmd, so the actual behavior after enabling THC is that axis.3.motor-pos-fb changes, while axis.3.motor-pos-cmd does not. And, if I understand correctly, then EMC checks difference between these two to calculate the amount of following error. So I have a question - is there a way to "tell" EMC, that joint.3 following error should be ignored, when and only when THC is enabled? But I suspect that I would get that following error as soon as THC is disabled. So can thc module be placed before axis.3.motor-pos-cmd? Or maybe something similar in this order: 1) taking axis.3.motor-pos-cmd value, saving it as "old value", e.g. axis.3.motor-pos-cmd-old 2) giving it to z-pos-in 3) calculating offset 4) giving new position data to z-pos-out 5) give z-pos-out value to axis.3.motor-pos-cmd Would something like this actually work? Thanks in advance! with best regards, Viesturs ------------------------------------------------------------------------------ What happens now with your Lotus Notes apps - do you make another costly upgrade, or settle for being marooned without product support? Time to move off Lotus Notes and onto the cloud with Force.com, apps are easier to build, use, and manage than apps on traditional platforms. Sign up for the Lotus Notes Migration Kit to learn more. http://p.sf.net/sfu/salesforce-d2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
