Siemens S7-300 appendix 5 S7 communication, Use in server mode for, Use as client, Configuration

Communication

3.2 Communication services

Reference

•Details on SFCs are found in the Instruction list, for more details refer to the STEP 7 Online Help or to the System and Standard Functions Reference Manual.

•For further information on communication, refer to the Communication with SIMATIC manual.

3.2.5S7 communication

Properties

A CPU can always operate in server or client mode in S7 communication: We distinguish between

•communication with unilateral configuration (for PUT/GET only)

•communication with bilateral configuration (for USEND, URCV, BSEND, BRCV, PUT, GET)

However, the functionality depends on the CPU. A CP is therefore required in certain situations.

Table 3-3	Client and server in S7 communication, using connections with unilateral / bilateral
	configuration
CPU		Use in server mode for	Use in server mode for	Use as client
		connections with unilateral	connections with bilateral
		configuration	configuration
31xC >= V1.0.0		Always possible at the	Only possible with CP	Only possible with CP
		MPI/DP interface, without	and loadable FBs.	and loadable FBs.
		programming the user
		interface
31x >= V2.0.0		Always possible at the	Only possible with CP	Only possible with CP
		MPI/DP interface, without	and loadable FBs.	and loadable FBs.
		programming the user
		interface
31x >= V2.2.0		Always possible at the	• Possible at PN	•	Possible at PN
		MPI/DP interface, without	interface with		interface with
		programming the user	loadable FBs, or		loadable FBs, or
		interface	• with CP and loadable	•	with CP and
			FBs.		loadable FBs.

The user interface is implemented using standard function modules (FBs) from the standard library of STEP 7, under communication blocks.

Reference

For further information on communication, refer to the Communication with SIMATIC manual.

3-8	CPU 31xC and CPU 31x, Technical data
	Manual, Edition 08/2004, A5E00105475-05