connect two PLCs MPI->Profibus DP

[Pandiani]

Hello,
we have two PLC in our small laboratory. One has CPU 315-2 DP CPU and other CPU 314. Is it possible to use profibus cable to connect these two PLCs (use DP connector on first and MPI connector on second) DP to MPI. Since other CPU doesn't have MPI, is it possible to connect DP cable to MPI interface. Is there any possibility to mess things up, I assume it won't work, but I'm afraid to try...
Thanks

 

[lhughes39]

Pandiani,

I may be mistaken, but I beleive that both of those PLC's have a MPI port, but only the 315-2 DP has a DP port. So you should just be able to hook up a MPI connection between them.

Below is a link to the tech specs on them:

http://www2.automation.siemens.com/simatic/ftp/st70/html_76/st7001_e.pdf

Look at page 133 under odering data.

Hope this helps.

Larry

 

[Werner]

You can connect these plc's via MPI. (Left port of 315-2DP is by default MPI) It is then possible to exchange some data between the two via global data. We connect plc's like this all the time. Make sure the plc's do not have the same MPI-address. (Hardware configuration)

Edit: Make sure to use profibus connector's. (Siemens/Phoenix). On both connectors set the end resistor to on. If the plc's are on different power supplies it migth be a good idee to use repeaters. (Seperating the two power supplies). For a small office application this might be overdone.

 

[Pandiani]

Ok, thanks, I assumed it's not possible to use Dp port on one and MPI port on other PLC. However I have profibus DP cable. Is it possible to use DP cable to connect two PLC via theirs MPI ports?

 

[PLucas]

Is it possible to use DP cable to connect two PLC via theirs MPI ports?

Yep, this is possible, there is no difference between the cable for DP and MPI.

Paul