S7-400 to S7-300 profibus s7 connection

I have an S7-400 (414-3) PLC which will be used as a data collector. It will communicate with a variety of existing S7-300s over a profibus network. Ideally I would like to use the GET function to retrieve data from each of the S7-300 plc's configuring an S7 connection in the S7-400 PLC using the CPUs DP port. My questions are as follows:

1. Can I use DP port of S7-400 CPU and DP port on S7-300 CPU?
2. If not, can I go DP port on Profibus CP module added to S7-400 configuration to DP port on S7-300 CPU.
3. Is only option to use dedicated DP CP module in all PLC configurations.

Notes: I do not want a multiproject solution, prefering to use connections to unspecified partners.

Any help/guidence on this is appreciated.

Hi and welcome to the forum!

I have some contraquestions.

When you plan to use DP, is the 400 master and the 300s DP slaves? In that case you run plain IO communication.

Or do you use all the CPUs as masters on the same DP network and with a conglomerat of slaves also? If yes, this should be reconsidered because the response times are going to multiply.

Or do you mean to use the MPI-interfaces?
Here you can use global flags if the data amounts are minor, or also S7 communication as you suggest.

Kalle

Currently I have no information regarding the S7-300 master/slave statuses. Giving that there are around 16 of them I need to communicate to I would prefer to find a solution that is not master/slave dependant (if possible of course).

My current limited understanding is that a possible solution is to fit a CP profibus module to the 400. From what I understand the CP443-5 Basic module is neither Master nor Slave and simply sits on the profibus network enabling the use of S7 communications. My thoughts are to use this module in conjunction with the Profibus ports on the 300 CPUs using the 400 to 'GET' the data (only 26 bytes each).

I think your suggestion will work, but you must use the MPI interfaces to the communication, do not touch/interfere with the existing DP busses.

And when you use the MPI bus, you must ensure that all CPUs have uniqe MPI adresses. If there are panels, this goes for those also.

Perhaps you could consider using some Ethernet/MPI converters from IBH-softec, Traeger, Helmholz or similar. Then you could skip the 400 and communicate directly via S7/TCPIP to a PC.

Kalle

DazEddy,
Perhaps you could give us a bit more information on how the systems are currently structured?
Do the S7-300 systems have IO on Profi?
If yes - describe the structure.

A little more info will go a long way!