MPI extending


Thread Starter


How do I extend an MPI to my shop so I can view all PLC's from my desk. I have 2 Profibus Connectors, 1 RS 485 repeater and 1 RS232 to MPI/DP adapter. The distance is about 300ft. A detail diagram would help alot please, like cables go to A or B connector and the switch on connector should be on or off. Thank you
Hello it is not a big problem. But you have to forget your MPI/DP adapter. You will need one PCI (CP5613) card for your PC and PRODAVE software from Siemens (or another MPI driver SW for your PC). If you have Step7 SW, even better. Just buy one more Profibus connector for your new PCI, extend your cabeling and play.
Thank you for the reply. I have a CP 5512 but I don't have the driver for it. I like to know more about how to connect the cable because i'm kind of new to this Profibus.
KEPWARE has an MPI OPC server that will talks over Ethernet to a small gateway that plugs onto the MPI port, essentially replacing the MPI cable with Ethernet. Your PC could support an unlimited number of connections.

Hakan Ozevin

You already have all the necessary equipment you need.

RS 485 repeater by Siemens has a PG port, linked to Profibus/MPI branch 1. Just connect your MPI adapter to this port. Now, using a profibus cable and a PB connector, connect branch 2 of the repeater to your CPU. Your PC and PLC are electrically isolated in this case. You do not need any extra drivers. You should however feed RS 485 repeater by an external 24 V DC supply.

A (pin 8) and B (pin 3) are existing as terminals on the PB connectors.

If you have several CPUs, terminating resistor of the last one (i.e. that one having a single PB cable on the connector) on the network should be ON, the rest should be OFF. On the last CPU, A1 and B1 terminals should be used. A2 and B2 will be terminated by the resistor.
Kepware offers a MPI to Ethernet converter that is built into a Profibus Connector. Use a standard Ethernet network to connect your panel to your desktop PC.