6/9/2011 11:27 AM | |
Joined: 10/7/2005 Last visit: 9/25/2024 Posts: 3022 Rating: (1054)
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Nicely researched Saruca and thanks too for the application description (it makes far more sense now what you want to do which helps in advising you). Profinet IRT (Isochronous Real Time) mode is indeed supported by thelatest 314C-2PN/P. In general Profinet IRT is specifically designed for decentralised control applications that requirefast and deterministicbehaviour (e.g. motion control) and your sorting application would possibly fall into that category too. Before you go down that path though, there's a few things to be aware of: 1.) IRTrequires that all hardware in the physical Ethernet chain (e.g. CPU, Switches, I/O Devices) are IRT capable (see also Why is hardware support required for using clock-synchronized real-time communication (IRT) in PROFINET?) A list of supported I/O controllers (e.g. CPU's) and I/O devices (e.g. ET200's)can be found HERE (and even though your 314-6EH04 is not in it, it would at least have a tick mark for "IRT" and possibly foralso onefor "Isochronous" mode which is the"Clock-synchronized" mode ). If you need Ethernet switches between the I/O Controller and I/O Device, make sure they have IRT capability. 2.) Profinet IRT is quite a different "beast" compared to Isochronous mode for Profibus. Isochronous mode for Profibus"simply" means synchonisationof the Profibus scan with the PLC scan to achieve deterministicbehaviour (or tightly reproduceable/cosistent update times). Isochronous mode for Profibusdoes NOT speed the bus up or makes the update faster (it actually creates slightly longer update times, but guarantees that these will be consistently reproduced and not exceeded). Profinet IRTon the other handis by itself typically by a factor of 10 faster than "normal" Profinet RT (Real Time), you additionally can then selectto have "Clock-synchronized" mode(sometimes also called Isochronous mode just to confuse people)to achieve the highest deterministics behaviour possible for Profinet. Given your application, a Profinet IRT based solution is arguably the technicallybettersolution than a Profibus based one. You may even consider using an ET200S Profinet I/O station instead of an ET200M one (it all depends on how many I/O's you need). The learning curve for this application will be quite steep though and possibly a bit more costly. As such, I wonder if perhaps a little IM151-7 (or IM151-8) ET200S CPU with local I/O's (or even the previously discussed1200 CPU) may be a better option (make itan Intelligent Slaveof your 314 CPU viaa now non time critical Profibus or Profinet link). Tough call which way to go, but you are doing your "homework" (research)first which is good and just in case you haven't yourself found ityet, here is the mainProfinet related link: Where can you find information on the topic of PROFINET? |
Last edited by: fritz at: 6/9/2011 11:37 AMfixed typos (most of them anyhow) Cheers |
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