Communication Problem With Siemans S7 414-2 PLC

[MarkNightingale]

Hi All,

I am having some communication problems with a Siemans 414-2 PLC.

Basically I am trying to download some changes I have made to the PLC code through the MPI port. There is a Profibus connection in the same X1 MPI port and I am 'piggy backing' my MPI PC adapter on to the back of this. When I look for accessible nodes, none show up.

I know all my settings are correct because I have been online with the processor before.

I have also tried to connect to the X2 DP port using my PC adapter on profibus but this also did not work.

I have tried a memory reset to reset all the Baud rates back to standard but this didn't work either.

Any help would be greatly appreciated.

Thanks
Mark

 

[PeterW]

On 400's I believe both ports can be Profibus, if there is a Profibus connection then it is set up as Profibus and not MPI.

Check the Hardware profile of the project file to see what it is set to, MPI or Profibus and what speed.

If the second port is not used you cannot just connecct to it, a Profibus network needs a Master and termination resistors.