View Full Version : S7 online
August 28th, 2006, 07:40 PM
How can I go online with 2 plcs on the same project without having to disconnect/connect cabling.P;ease look at the attachment of netpro.
I am currently only able to go online with plc no. 2 - KT-Presse.
Both plcs do "talk" to each other for data in their operation.
What do I need to look for to determine online capabilities on both plcs.
August 29th, 2006, 01:25 AM
I very rarely go on-line via MPI, usually only for initial configuration, so I don't know if MPI supports the ability to go on-line with more than one. MPI is quite slow so maybe limited.
With Ethernet, you can have more than on PC on-line as well as more than one PLC to a PC, but you only have ethernet to one PLC.
August 29th, 2006, 01:39 AM
Just make PG/PC object in your project. This should have MPI interface and/or Ethernet interface.
Then assign this object to your PG by clicking right mouse button on it and select PLC>Assign PC/PC... This gives you ability to go online with both PLC, even you are connected through ethernet. Step7 can make route to S7-300 via CPU416-2. Of course you can communicate over MPI network too.
August 29th, 2006, 07:42 PM
I think the online path that plc2 uses at the moment is via the profibus adapter.From what I can see in netpro there is no physical link between both the plcs on the profibus networks. Plc1 does not have any ethernet connections. I have tried assigning existing pg/pc for ethernet and mpi but still cannot access plc1 and I also lose communication with Plc2.
August 30th, 2006, 02:23 AM
According to your diagram, there is a common MPI network for both PLCs and the PC.
There is an ethernet connection to PLC2.
And there are three completely separate Profibus networks.
So, if you are considering accessing PLC1 via routing then it can only be via MPI from PLC2. In that case you could just have used MPI without routing.
That you cannot access any PLC via MPI should be investigated a bit further.
What type of MPI adapter do you have on the PC ?
By the way, in order to use routing for programming, you have to add a PG/PC object in NetPro like gregoryg suggests.
However, I think that you have a problem on MPI that must be solved first.