On Mon, 2012-02-27 at 17:37 +0000, Chris Morley wrote: ... snip > I personally never got the slave version to work but that is probably because > I don't understand TCP connections. > Do you connect two computers with crossover cable or must you use a router? > How do you find the address?
There may be a function that can look this up, but I think it's hard for the API to know what network the app needs to use, although 99% of the time the host has a single Ethernet port making the practical choice easy. I got the libmodbus 3 unit-test demo to work by just doing a ifconfig to to get my IP address and plugged that in. That's all that was needed. RTU over TCP is probably a different story. My LinuxCNC master could send queries just fine, but the unit-test slave isn't set up to return anything interesting. Successes for unit-test demo seems to be a lack of error messages. > Marc (Classicladders creator) tells me he has tested it and it worked. > He just never supplied step by step instructions. > > I can see no reason not to have a slave feature. If you have a separate > computer > you could use it as a smart PLC without slowing down your main computer. > or have the second computer run windows (CL runs in windows too) > The original CL was made to be able to be included in embedded machines. > > Also it would allow you to test your Modbus connection which is probably why > Marc coded it. > > If you figure out how to use it please add it to the official docs. > > Chris M I don't know Ladder so I'm not much help with related issues, but I plan on recording what a learn with libmodbus. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
