I'm not an EMC expert either. The core is pretty dated; based on some NIST code from the early '90s. Most of the supported hardware is either parallel port interfaced, or internal ISA/PCI DAQ boards. Given that the parallel port is dying out, I wanted to look at the viablity of using RTNet to talk to the motion hardware.
Given both EMC and RTNet are open source, I can look at enhancing either side. I'll post a question on the EMC mailing lists and see what the experts over their think. Thanks, Frank > -----Original Message----- > From: jan.kis...@web.de [mailto:jan.kis...@web.de] > Sent: Wednesday, 16 December 2009 11:49 AM > To: Frank Tkalcevic > Cc: rtnet-users > Subject: Re: Synchronising the sync frame > > (please keep CCs) > > Frank Tkalcevic wrote: > > Yes, that's an option. However, the way the application is > > structured, the EMC core is responsible for controlling a > whole series of plug in modules. > > It doesn't know if the module is going to use rtnet, or needs to be > > re-sync'ed. Either way, it sounds like I need to add a > method to get > > one of them to move their sync time. > > > > I don't know how EMC2 is structured in details. But if it > lacks a way to trigger cyclic jobs on external events instead > of its internal clock, that sounds like a deficit. Consider > you had to synchronize on a hardware-based (Ethernet) > fieldbus that is not as tunable as RTmac/TDMA... > > Jan > > > > > > >> -----Original Message----- > >> From: jan.kis...@web.de [mailto:jan.kis...@web.de] > >> Sent: Wednesday, 16 December 2009 10:46 AM > >> To: Frank Tkalcevic > >> Cc: rtnet-users@lists.sourceforge.net > >> Subject: Re: Synchronising the sync frame > >> > >> Frank Tkalcevic wrote: > >>> Is there any way to set when the TDMA Sync frame is output? > >>> > >>> I'm using RTNet with EMC2, the enhanced machine controller. > >> It works > >>> in realtime by scheduling a "servo thread" to run at a predefined > >>> interval, 1ms in my case. In the servo-thread, emc gathers data, > >>> processes the data, then generates outputs. To get this to > >> work with > >>> my slave device, I need to have the latest status data > >> ready when the > >>> servo thread starts - that is, I need to be able to set the > >> sync frame > >>> to begin about 100us before the EMC servo thread starts. > >>> > >>> Is there anyway to "adjust" the sync frame? > >> Why this way around? Why not establishing the system > period via TDMA > >> and synchronizing EMC2 on it? TDMA has an API for this (see > >> examples/xenomai/native/tdma-api.c). > >> > >> Jan > >> > >> > > > > ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ RTnet-users mailing list RTnet-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rtnet-users
