Description
One connection resource is required in the S7-300 CPU for each of the following communication connections of the Industrial Ethernet CP.
 

Communication connection	Service	TSAP
PG communication via S7 server	Web diagnostics, for example for displaying the diagnostics buffer of the CPU Set time in CPU 318 Applets, for example to read MLFB or status of the CPU Bacnet (read system status list (SSL)) ERPC (read system status list (SSL))	0x01
System connection via S7 server	FTP server (read and write access to file DBs) FTP client (read and write access to file DBs) Applets (read and write access to CPU data) Bacnet (read and write access to CPU data) ERPC (read and write access to CPU data)	0x03
System connection	FETCH and WRITE via SEND/RECEIVE connection PBC for OP multiplexer	0x03

If the FETCH / WRITE, PBC for multiplexer, FTP and Web diagnostics services are used simultaneously in the Industrial Ethernet, 4 connection resources of the S7-300 CPU are occupied.
An Industrial Ethernet CP can occupy, for example, a maximum of 4 connection resources in the S7-300 CPU; this one connection resource each for:

• PG communication via S7 server (TSAP=0x01)
• System connection via S7 server (TSAP=0x03)
• System connection SEND/RECEIVE (TSAP=0x03)
• System connection OP multiplexer (TSAP=0x03)