Siemens Remote I/O

I am confused about the SIMATIC ET 200M modular I/O station.
Can this be used with a S7-400 PLC as a master? Or just with
a S7-300 SERIES PLC? Does anyone have a sample project
layed out with using the modular I/O?

If a PLC is a Profibus-DP master then you can use any Profibus-DP slave I/O with it. So if you have a Profibus-DP-capable S7-400 CPU then you can use ET200M. Conversely there are some S7-300s which don't have DP capability so you can't use ET200M with them.

Be aware, the actual I/O modules can be used in different configurations -
- S7-300 CPU racks use these modules directly as part of the I/O structure.
- S7-300 expansion racks (connected to the CPU rack using IM360/361 interface modules for example) use these modules directly as part of the I/O structure.
- ET200M Profibus-DP slaves (connected to a DP master using an IM153 interface module) use these modules.

Whether you regard them as S7-300 modules or ET200M modules depends on the application.


Regards

Ken.

You can experiment with the configuration without really having an S7-300 or ET200M at hand.

In the Hardware configuration of STEP7, pick a CPU with a Profibus port, or add a CP342-5 to the S7-300 rack.
Then enable the Profibus port.
A Profibus network will appear (it is just a "wire" in the HW config).
Highlight the Profibus network, and then add an ET200M and corresponding i/o modules.
Experiment with other Profibus setups. Try ET200S, and some MicroMaster drives etc. etc.