S7 Basic Communication; Table 4-2 Sfcs For The Basic S7 Communication - Siemens SIMATIC S7-400 Manual

Communication
4.2 Communication services
4.2.4

S7 basic communication

Properties
S7-based communication is used to exchange data between S7 CPUs and the
communication-capable SIMATIC modules within an S7 station (acknowledged data
communication). The service is available via MPI subnet, or within the station to function
modules (FM).
You do not need to configure connections for basic S7 communication. The integrated
communication functions are called via SFCs in the user program.
SFCs for the Basic S7 Communication
The following SFCs are integrated in the operating system of the S7-400 CPUs:
Table 4-2 SFCs for the Basic S7 Communication
Block Block name
SFCs for external communication
SFC 65 X_SEND
SFC 66 X_RCV
SFC 67 X_GET
SFC 68 X_PUT
SFC 69 X_ABORT
SFCs for internal communication
SFC 72 I_GET
SFC 73 I_PUT
SFC 74 I_ABORT
Reference
● Refer to the
● You can find detailed descriptions of the SFCs in the
4-8
Brief description
Secure transmission of a data block to the communication partner.
Reading variables from a communication partner
Writing variables to a communication partner
Cancellation of an established connection with transmission of data
Reading variables from a communication partner
Writing variables to a communication partner
Cancellation of an established connection with transmission of data
operation list
CPU.
Standard Functions
reference manual.
to learn which SFCs are included in the operating system of a
STEP 7 Online Help
S7-400 Automation System, CPU Specifications
Manual, 10/2006, 6ES7498-8AA04-8BA0
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