s7 programming

[Guest Guest_paul]

i am looking for the mp1 connections on aS7 314 processor ie TX+ TX- etc.

[Guest Ken M]

Hi The strange thing is that although Siemens don't seem to publish the MPI pin connections in any of their CPU manuals, they do publish them in the manuals of things which connect to the CPUs! So the HMI manuals for items like the MP270, MP370 etc all give clear indications of the MPI port. Basically it's just Pins 3 & 8 for data and 5 for the Ground. Since it's RS485 rather than RS422 there isn't really a Tx+, Tx- thing - they just show it as Data A and Data B. Regards Ken.