Hi Andy , thank you for the reply. It's not the matter of change the discussion object . But when somebody as expert as you are is writing an important concept I would like to understand it properly. Sorry ...
On Fri, May 15, 2015 at 10:57 AM, andy pugh <bodge...@gmail.com> wrote: > On 15 May 2015 at 07:26, alex chiosso <achio...@gmail.com> wrote: > > > And when an where the logic elaboration should be ? > > There isn't any HAL logic elaboration as you seem to be describing it. > > All the HAL logic is handled by individual components. Those > components read their inputs and update their outputs one by one in > the order they are placed in the thread. > > (Some components have more than one "function" and strictly-speaking > it is the functions that execute in the order they are added to the > thread) > > What I am saying is that there is that the sequence that things appear > in the HAL files has little bearing on the sequence in which they > happen. > When LinuxCNC starts it reads through all the HAL files in sequence > and sets up all the HAL connections. This is a one-time process at > startup, and from that point on the HAL file is not looked at again. > It is a mistake to imagine that the HAL file is somehow "interpreted" > every cycle as some people seem to. This is why it isn't a programming > language. > > If there are two HAL files, and the first contains: > > addf parport.0.read thread1 > addf and2.0 thread1 > addf parport.0.write > > and a the second contains > > addf or2.0 > > Then the sequence is that the parport is scanned and the > parport.0.pin-in-NN pin values are updated > Then the and2.0 funsction runs, reading its inputs and updating the outputs > Then the parport.0.write function runs, updating the voltages on the > parport output pins. > Then the or2.0 function runs, reading its inputs and writing its outputs. > > I rather worry that my original intention of trying to make HAL > simpler to understand has just become subverted by discussion of > technical details that were not part of the original question at all. > > > -- > atp > If you can't fix it, you don't own it. > http://www.ifixit.com/Manifesto > > > ------------------------------------------------------------------------------ > One dashboard for servers and applications across Physical-Virtual-Cloud > Widest out-of-the-box monitoring support with 50+ applications > Performance metrics, stats and reports that give you Actionable Insights > Deep dive visibility with transaction tracing using APM Insight. > http://ad.doubleclick.net/ddm/clk/290420510;117567292;y > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
