connection between two cpu S7-315-2DP


Daniel Chartier

depending on the quantity of data you need to transmit, Siemens has many ways to exchange between its CPUs; easiest is Global Data, on the MPI network, quick, reliable, but for limited amounts of data (no files); almost as easy, if you have Profibus-DP CPUs, is to use one as Master and the other as slave, create exchange tables (up to 128 words In and 128 words OUT per exchange) in DBs ansd read/write through Profibus. Next, you can transfer different size files between the CPUs with standard functions (XPUT/XGET, SEND/RECIEVE, LSEND/LRECIEVE) over MPI, Profibus or Ethernet (the Siemens Industrial Ethernet). The online Help in Step7 and the electronic manuals (installed with Step7) will give you all the info you need.
Hope this helps,
Daniel Chartier
The easiest is to put both programs under one project name and use the global data table. Right click under MPI in the Simatic Manager. Just fill out the table.

Be sure both cpu's have different MPI addresses and that the MPI port is networked "yes".

I hope this helps.
You can use PROFIBUS. use a DP/DP coupler between the two PLC's. The DP/DP coupler makes the DP masters on the othe plc look like normal slave I/O. You can buy differnt DP/DP couplers Depending on the amount of bytes you want to pass between them.
the best option is by profibus, its inmediatly, because this plc have integrated port, if you have step7 v5.0 or 5.1, and ncm, do you must to have the examples in the manual NCM profibus and program samples instaleds in your hard disk, or you can obtaint in the siemens site, you can connect also by global data, by the mpi port, but this work for a few data also it's more easy,
you can configure in the hardware configuration software, look in the help for detailed instruction, i have any programas for comunication, send me a email ([email protected]),
for a sample.