Posted 6 Nov 2010 I want to buy S7300 unit for training purpose, I need the lowest price for basic training ( in details rack , power supply , IO,..) and if I want to make advanced training in future that may need profibus, other communications or interfacing options can I add it to my basic units , if I can't which unit should i buy in first ( that can expand later) thx Share this post Link to post Share on other sites
Posted 6 Nov 2010 Hi gendy. Any S7-300 CPU can be expanded with an ethernet or profibus CP. So any low cost CPU will do for starters. I think you should also look at the IM151-8. This is a CPU that has ethernet onboard with Profinet capability. And it has quite enough memory and performance while still being fairly affordable. The IM151-8 can be expanded with a Profbus master interface if needed. But if you are looking for something that points to the future then forget MPI and Profibus. Ethernet/Profinet is the way things goes. Share this post Link to post Share on other sites
Posted 6 Nov 2010 Hi, many thanks for your reply, I didn't deal with IM151-8 before , I was think about 313C or similar C series CPU or standard CPU with I/O Like 312,.. but as I read quickly about IM151-8 it can work as stand alone PLC ( not normal distributed I/O) so if I use it , can I do all the functions of CPU with the same manner like diagnostic buffer, download program ,..etc?? for building system can i use the same I/O? Share this post Link to post Share on other sites
Posted 8 Nov 2010 hi JesperMP i want to compare between CPU313C, and IM151-8 can you help me in that Share this post Link to post Share on other sites
Posted 9 Nov 2010 The 313C is a "brick" PLC with integrated i/o. It has only an MPI port for online access. It can be expanded with S7-300 modules. You get relatively many i/o for a low cost. It has not been updated to the latest generation, and I am beginning to doubt that it will ever happen. The IM151-8 is a CPU that either expands with ET200S modules directly, or via Profinet. It has been updated to the latest generation recently. You get a more powerful CPU that has more memory and Ethernet/Profinet in the shape of a 3-port switch. I dont like "bricks", but do like the modularity of the ET200S system. And I demand to have ethernet, even for the smallest project, so the IM151-8 is a very good starting point PLC, whereasI would never chose the 313C. Those are just my preferences of course. Share this post Link to post Share on other sites