http://www.ohmark.co.nz/news090113.html
ie: yes.. The pic software implements a most of the modbus RTU spec, which memory space for 16 analog I/O and 256 digital I/O depending on the PIC you use and adding some extra hardware. Relays are trivial... The end-game for this project will be a full AJAX based HMI, classic-ladder PLC and modular RTU's. The screen-shot on that page shows 'buttons' which reflect the state of outputs and were clickable to turn on/off the NPN outputs on the RTU. The project stalled earlier in the year as I changed jobs, but I'll be back into it in a few weeks as I have some projects coming up that will need a decent PLC. The only progress I've made since the last post on the site was some debugging in classicladder, and building a thermocouple amplifier for the RTU. Classic ladder and an HMI are probably not what you want to get into, although if you're really bored I could go on for hours about process control, I used to do some work with industrial automation and embedded control systems. Cheers, Me. On Sat, 2009-07-11 at 18:07 +1200, yuri wrote: > 2009/7/11 Chris Hellyar wrote: > > Hi... > > > > http://www.ohmark.co.nz/news090120.html > > > > etc... > > > > :-) > > > > Using libmodbus from launchpad (There's two libmodbus's around, one is crap, > > the other is the one I've contributed some bug fixes to. :-) ). > > > > If you're pic-aware You're welcome to have some of my test code, I've not > > done any work on this for a while, but I have a fully functional modbus RTU > > (rs485) setup, and sample code for GCC on linux, and VB/windows that has > > survived a fair bit of testing. > > Very good. Your project seems to be a temperature logging thing. > Could it be *easily* modified to relay control? > > No, I'm not pic-literate. > > Thanks > Yuri >
