thanks.. bkt
2017-06-12 0:47 GMT+02:00 Nicklas Karlsson <[email protected]>: > I read and it mostly seems to be about security. Realtime scheduling make > sense for every task which is periodic or may be treated as a periodic > task. A really good example is a serial receive buffer since data will be > lost if not handled periodically. > > GUI I usually treat as periodic task with a dead time of about 20-50 > milliseconds even though it seldoms happens. Video I guess is about 30-50 > milliseconds. Servo loop is around 1 milliseconds and even though little > computational power is required ordinary computer seems to have problem > with this. > > They mention something about support for a real time operating system and > for linuxcnc the kernel RT patch is used or RTAI. On a micro controller I > most often use an interrupt with suitable priority, software is most often > simple with only a few well known interrupts so most often it works really > well. > > > The most useful scheduling schemes are Earliest Dead Line first > https://en.wikipedia.org/wiki/Earliest_deadline_first_scheduling and for > static priority rate monotonic which may be implemented with nested > interrupts with priority https://sv.wikipedia.org/wiki/ > Rate-monoton_schemal%C3%A4ggning > > Dead line should be equal to periodic which most often is possible. For > video with a dubble buffer, for serial receive buffer interrupt is > triggered then buffer is half full, ... It is commmon to talk about jitter > which make som sense but for properly implented EDF or rate monotonic > scheduling jitter within period make no difference. > > > Here http://linuxcnc.org/docs/2.6/html/code/Code_Notes.html at "4. > Architecture overview" is probably what you need to understand how the > different parts of linuxcnc is put together. The real time part I want to > put on simple computer and the GUI on an ordinary computer since they are > readily available cheap. There are two advantages: I want to keep real time > communication local and remove real time demand from ordinary computer. > > > Regards Nicklas Karlsson > > > > On Sun, 11 Jun 2017 23:19:27 +0200 > theman whosoldtheworld <[email protected]> wrote: > > > see these: > > https://blog.qt.io/blog/2017/05/17/integrity-rtos-support-qt-5-9-lts/ > ... > > As you said, me too I try is little bit hard use qt c++ program instead > > Lcnc c/c++ for driving servos machines .... but it promise rtos realtime > so > > sometings is for certain possible ... any how the goal for new qt5.9 rt > is > > automotive industries ... not robotics or chips machines ...the common > > denominator is sending realtime command signals and receiving them, a > > little logical work to make the signal available and allow the operator > to > > see or send these signals. Taking the sums I think is the first test to > > pave the way for the qt to the future automatic driving machines. > > > > my intention is use qt5.9 to interface a gui using a modern opensource > > industrial bus, with other electronics devices and some pc with Lcnc > > without gui.I'm not going to use the industrial buses to drive the servo > > ... I find it safer to use the command and safety buses (even in the > servo) > > and use traditional piloting for the positioning and the feedbak ... so > two > > different line to the servo on two totally different channels, analogue > for > > driving, digital for safety and functional. It's like having two dogs who > > are guarding one against each other. > > > > The project would be: to create an rt component that starts as if it > were a > > gui at opening lcnc, the component starts a server connection of some > > industrial bus and waits for queries from slaves or slaves, as for > example > > some commands / requests may arrive From a plc of security; Create a gui > in > > qt on remote pc having its main thread, secondary ones of service and > then > > one or more thread rt for communication to pc lcnc via industrial bus rt > or > > other devices (eg plc security). > > > > I've already relayed this thing with modbus as a test ... but modbus, > even > > turning very fast with new technologies, even over 115000, always sends > 16 > > bits at a time ... for good remote control Of Lcnc serve at least 48 bits > > for the on / off commands + others to have floats .... so a fast and > large > > bus is what you need ... believe that's why Sebastian has used QUIC. > > > > I'm happy to chat with you about this. > > > > bkt > > > > > > 2017-06-11 17:21 GMT+02:00 Nicklas Karlsson < > [email protected]>: > > > > > On Sat, 10 Jun 2017 22:48:47 +0200 > > > theman whosoldtheworld <[email protected]> wrote: > > > > > > > ... thanks for your advice ... but there are 3-4 solution for these > > > things > > > > .... > > > > But at present I am more concerned with understanding the use of > various > > > > Lcnc files than any other. > > > > > > The lcnc files are a little bit hard to understand. The *.hal files are > > > almost like netlists used for schematics. It make a lot more sense to > > > visualize the configuration in schematic. > > > > > > There are some old almost working example with geda gschem, whenever I > > > have a few I will try to get the script to work. I also heard something > > > about rockhopper, it is also vizualized graphically although this was > some > > > kind of web based interface, html have limitations then it come to user > > > interfaces and usually have a second or so delay whenever something is > > > pressed. Graphical representation with gschem should be simple, script > is > > > currently in python while most other output from gschem via gnetlist > is in > > > scheme language. > > > > > > > > > I am fully with you then it come to split application in non real time > GUI > > > and real time. And at least partly with you then it come C++ and do not > > > like python programming language but use whatever is available or have > been > > > used before. > > > > > > > > > Then it come to GUI I like the glade interface designer and automatic > > > connection of callback functions. Automatic connection of callback > > > functions are available in C but not C++ and for python I do not know. > > > > > > ------------------------------------------------------------ > > > ------------------ > > > Check out the vibrant tech community on one of the world's most > > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > > _______________________________________________ > > > Emc-users mailing list > > > [email protected] > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > ------------------------------------------------------------ > ------------------ > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
