> The only LinuxCNC via Ethernet I know of is the hacked version of > MiniEMC2, but others could probably tell you about efforts I am unaware > of. The multiple machine coordination with overlapping work envelopes > is a topic a few of us have discussed working on from time to time, but > I do not think there is anything substantial been done in that arena > yet. Can you tell us more about your setup and needs?
Not much but the configuration who is robots serving a cncmachine, all driven by LinuxCNC. I have right now no more details about that. Also, can you > help with programming on the LinuxCNC side, or is your programming > experience limited to g-code? I know C-programming fairly well and have been active for a number of years and can obviously also obfuscate C++ if it's necessary. pcb2gcode is a piece of c++ who as I mentioned, did a slight modification to recently but you can't expect any stringent adherence to established c++ programming practices right now. > Looking at the NTP documents and specs, it looks like under ideal > circumstances it can hold 1ms in local area networks and ~10ms across > the internet. With that is sounds like you would want to set up a local > server, and synchronize all the machines from that. Yeah, that's my thought. At ~1ms you should > be able to easily set up a reasonable safety margin and coordinate the > motions between different machines, but probably not coordinating > individual axes if they are running fast (anywhere near 1m/s +). > Personally, I would like to take a CAGD approach with definable work > envelope semaphores or critical regions, but that's just me... Actually > after thinking about it for two seconds, a semaphore into critical > regions would work without the need of NTP coordinated clocks. The > trick would be to set up some equivalent "move to position and wait for > wait for a 'GO' signal", at which point that machine owns that space. > The problem here is that the g-code would have to be aware of the > critical regions. True, certain codes must wait for an external signal before completion, possibly with a timeout triggering an error message. It would be better if you could analyze the motion > outside of LinuxCNC and then automatically insert the entry/exit into > the critical regions. I see how I could easily do that using > intermediate output from the simulator, but that is getting into CAGD > analytical territory and techniques. > > EBo -- Well, I'm not aware of CAGD but I thought about a triggering function who I believe is used in four+ axis situations on certain CNC-mills where U need to synchronize the fourth axis with the first three. I haven't digged much into that either even if there is such a machine in the shop who I am programming but the problem is I believe, fairly equivalent? In FANUC controls they seem to have functionality for that when U read their manuals even if it is briefly mentioned. (manual B-64124EN/01 , page 201, External motion function) So extending this to subordinate controls might be a way out if LinuxCNC have something similar? / Roger ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
