Siemens SIMATIC S7-300 Hardware And Installation Manual page 57

Industrial Ethernet
Industrial Ethernet in an open multivendor communication system represents the
SIMATIC network on process and cell level. Industrial Ethernet is suitable for fast
and high-volume data exchange and offers offsite networking options via gateway.
With S7-300 CPUs, you can implement Industrial Ethernet connections only with
the help of communication processors.
Actuator/Sensor Interface (ASI)
The ASI, or actuator/sensor interface, represents a subnet system on the lowest
process level for automation systems. It is used especially for networking digital
sensors and actuators. The maximum data volume is 4 bit per slave station.
With S7-300 CPUs, you can connect to an ASI only with the help of communication
processors.
Same configuration for MPI and PROFIBUS-DP
For your MPI network configuration, we recommend you use the same network
components as in a PROFIBUS-DP network configuration. The same configuration
rules apply in this case.
For reference literature ...
we especially recommend the manual Communication with SIMATIC.
S7-300 Programmable Controller Hardware and Installation
A5E00105492-01
Configuring
4-29