MPI Cable

Hi all,

I want to make a MPI cable.
Someone have the diagram?
Thanks for your help.

LGN

Hi, try to type in in Google MPI cable or something like this.

I have found also a thread in this forum about MPI, here is a link:
http://www.plctalk.net/qanda/showthread.php?t=4228

I think you'll have to turn to Siemens. Best is to take a lot of $$ to convince them to sell it to you.

Regards,

After re-reading the original question , I want to reconsider my answer. I assumed you were talking about the PC-MPI converter (as most questions are about when it comes to MPI cables).

If you're talking about a simple cable then you can use the following info:

Pin 7: signal A
Pin 3: signal B
Pin 1: shield

The signals are simple RS485 signals at 187.5 kbaud. Connect the connectors with a twisted pair cable, characteristic impedance should be around 120 Ohm. The connection at both ends has to be terminated with a 120 Ohm resistor.

If you want to avoid problems with interference from high-power and/or high-frequency sources, use the cable and connectors from Siemens.

Regards,

Hi Jean


I used to made a MPI cable with diagram below, and it worked very well.

D 9 PIN --------D 9 PIN
3 ----------------3
4 ----------------4
5 ----------------5
8 ----------------8

It is the cable connnect from PC Adapter (Siemens) to PLC.

You're quite correct. There was a typo in my previous post: signal A is on pin 8, not pin 7.

I'm very sorry.

In most cases it is not needed to put the wires on pins 4 and 5. These are only used to provide power from the PLC to the attached adapter. Connecting these between PLCs might introduce rather large currents flowing there because you are placing power supplies in parallel. The original cable and connectors from Siemens use only two wires and a shield.

Kind regards,

Hello I want to connect CPU3131C-2Dp to OP73 By MPI cable
but I don't now MPI wiring layout.

or 2-wires Profibus cable with 2 Profibus socket

Just a small correction. The two purple switches in the Profibus sockets, should be in the ON position.