siemens MPI port


Thread Starter


to connect four separate c7400 units to scada, I want to use the built-in MPI ports in multipoint config to one port on the PC. Any idea on the MPI pin wiring diagram? Any answer is most appreciated.
To connect the C7-MPI ports to a PC simply use standard Profibus cables and connectors. On the PC side you will need a bus card that can "talk" the MPI protocol such as the CP5511 (PCMCIA), CP5613 (PCI), or CP-5412 (ISA). From here it will depend what your trying to do; their are drivers available for C, OPC, and more most major HMI/SCADA packages. MPI, a sub-set of Profibus, is deterministic and runs at 187 KBaud. It is used the "programming" port for the C7/S7 PLC's and can be used for communications with HMI's, PC's and for peer-peer communications among the PLC's. Good Luck, Mike

Helmut Meissner

Hello John Use the Siemens MPI/L2 Plugs and the violet cable. that would bring less troubles. For your information the pinning of the MPI-Connector: Sub D In/Out Short Signalname/function 01 -- NC No connection 02 Out M24V Ground 24 Volt 03 In/Out LTG_B Data-Line B 04 Out RTS-AS RTS from Automation System 05 Out M5V Ground 5 Volt 06 Out P5V Power 5V 07 Out P24V Power 24V 08 In/Out LTG_A Data-Line A 09 In RTS-PG RTS to Automation System (from Prog.Device) Termination: P5V M5V 06 ---R390--- 03 ---R220--- 08 ---R390--- 05 ! ! LTG_B LTG_A Source: Greetings from Germany Helmut Meissner


The MPI connector comes with a built in terminal resistance option. Turning off the terminal resistance, you can extend the network using another pair of cable. You can order the MPI connectors seperately and use any two wire cable (the recommended cables ofcourse yield best results). You will find the wiring scheme with the ordered connectors. Clear Skies! Omer Aziz

Dobrowolski, Jacek

Hi John, Why don't you use Siemens MPI plugs ? Then all you need to take care about is only to connect by a MPI cable all A terminals together and the same with B terminals. You've got also terminators built into plugs. Regards, Jacek Dobrowolski Software Eng. Automation Department Secondary Division International Tobacco Machinery Ltd. POLAND mailto: [email protected]