Siemens Simantic Net NCM for Industrial Ethernet S7 - Manual (Page 25)

Communication via Ethernet CPs in S7 Stations
25
SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06
Configuring S7 Connections
Create S7 connections to use S7 communication for data exchange between two
SIMATIC S7 stations.
For more detailed information, refer to the STEP 7 Description /6/ /8/.
Notice
S7 connections via routers are supported only within a STEP 7 project but not bet-
ween partners in different STEP 7 projects of a multiproject!
Interface in the User Program of the S7 Station
You use SFBs (for S7-400) and FBs (for S7-300) in the user program.
Block type 1) Client Server Described in
SFB / FB12 BSEND x – STEP 7
D
t ti /9/
SFB / FB13 BRCV x
Documentation /9/
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 S7-300
Notice
Please remember the following points regarding data consistency in your user pro-
gram:
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 bounda-
ries, data inconsistency may arise during transmission using S7 communication!
For more detailed information, refer to the STEP 7 documentation /9/.