AB to Seimens. Profibus gateway

Hi.

We have 3 Siemens S7 connected together on a profibus network. We also have a Compactlogix PLC which requires data that is in the Siemens S7’s.

Prosoft make a stand alone gateway.

The Prosoft “ EtherNet/IP to PROFIBUS DP Slave Communication Module.

Part Number 4205-DFNT-PDPS “

looks like it can connect onto the Ethernet network and allow us to read and write data to the Siemens PLCs. My knowledge of Siemens and profibus is weak. Will one gateway allow us to talk to all 3 Siemens and are there any other pitfalls, traps etc.

Regards Alan Case

Hello Alan;Your CompactLogix module gateway will be seen as a slave on the Profibus network, then. Prosoft makes very good comm equipment (I haven't worked with this one precisely, but I have used their Modbus and Profibus-DP master cards for Controllogix and SLCs), so you should have no problem there.
Now, how many of those S& CPUs are masters on the bus? Here is a quote from some Profibus Web-based documentation that you might want to look at:

Multi-Master Multiple masters are possible with ProfiBus DP, in which case each slave device is assigned to one master. This means that multiple masters can read inputs from the device but only one master can write outputs to that device.

Click to expand...

So if your CompactLogix "slave" is configured on a bus with 3 S7 masters, then all S7s can read from it, but only one can own it and write to it.
There are workarounds to this; give us details on the topology you plan to use, we can have a look and work this out with you.
Daniel Chartier

I will have to get the exact layout of the Profibus network. It is 3 states and 1 sea away from me. (Tasmania) At present I am calculating a budget price and a rough feasibility study. Thanks, Alan Case

Hi Alan,
I use Siemens S7 PLC's together with Citect SCADA. Most of
my recent projects are in Asia (Korea, Malaysia and India)
I often handle Communications with other manufacturers equipment
by using .dbf files in Citect. This works well for
reporting functions but might not be suitable for real time
tasks. Anyway, just a thought as it could be easier than
networking the different PLC's.