Siemens S7-300 - 3.2 Parameter Assignment

Communication via Ethernet CPs in S7 stations
1.5 S7 communication via Industrial Ethernet
Configuring and commissioning S7 CPs for Industrial Ethernet
Configuration Manual, 09/2013, C79000-G8976-C182-13
27
Interface in the user program of the S7 station
You use the following program blocks in the user program:
Block type / instruction
Client
Server
Described in
SFB / FB12
BSEND
x
-
Online help in STEP 7
SFB / FB13
BRCV
-
x
SFB / FB15
PUT
x
-
1)
SFB / FB14
GET
x
-
1)
SFB / FB8
USEND
x
-
SFB / FB9
URCV
-
x
SFC / FC62 CONTROL (S7-400) /
C_CNTRL (S7-300)
x x
2)
1)
you do not need to configure a connection on the server
2)
for S7300
Note
Remember word boundaries
Remember the followin
g points regarding data consistency in your user program:
In the CPU of the S7 station, the read or written information is taken from the S7 user
program into the operating system or copied from the operating system to the S7 user
program in blocks of 8 or
32 bytes (depending on the firmware version).
If information in the word or double
word format is located across such boundaries, data
inconsistency may arise during transfer using S7 communication!
Notes on S7 communication between PC/PG station and S7 station
Applications in a PC/PG station communicate with the S7 station via an OPC interface or
SAPIS7 interface for operator intervention, monitoring and control.
The S7 stations use the integrated program blocks (client and server functionality at both
ends).
The following general requirements must be met by a PC/PG station for S7 communication:
● The following are installed in the PC/PG:
– an Ethernet CP;
– an interface for S7 communication: SOFTNET S7 for Industrial Ethernet or software
from the SIMATIC NET CD.
● The CPs in the S7 stations are supplied with a MAC/IP address (use the default MAC
address or set an IP address).
To be able to use S7 communication with the SIMATIC S7 PLC from the PC, address the
CPU
module as the target in the SIMATIC S7 station in your PC application.