Siemens SIMATIC PCS 7 CPU 410-5H System Manual page 245

● You can configure fault-tolerant S7 connections using the integrated PROFINET IO
interface.
Note
Downloading the connection configuration during operation
When you load a modified connection configuration during operation, connections which
have been set up which are not affected by changes in the connection configuration may
also be aborted.
S7 communication allows you to transfer a block of up to 64 Kbytes per call to the SFB. An
S7-400 transfers a maximum of 4 tags per block call.
SFBs for S7 Communication
The following SFBs are integrated in the operating system of the S7-400 CPUs:
Table 15- 6 SFBs for S7 Communication
Block Block name
SFB 8 USEND
SFB 9 URCV
SFB 12 BSEND
SFB 13 BRCV
SFB 14 GET
SFB 15 PUT
SFB 16 PRINT
SFB 19 START
SFB 20 STOP
SFB 22 STATUS
SFB 23 USTATUS
Integration into STEP 7
S7 communication offers communication functions through configured S7 connections. You
use STEP 7 to configure the connections.
S7 connections with an S7-400 are established when the connection data is downloaded.
CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB
Brief description
Send data to a remote partner SFB of type "URCV"
Receive asynchronous data from a remote partner SFB of type "USEND"
Send data to a remote partner SFB of type "BRCV"
Receive data from a remote partner SFB of type "BSEND"
With this data transfer, a larger amount of data can be transported between the
communication partners than is possible with all other communications SFBs for the
configured S7 connections.
Read data from a remote CPU
Write data to a remote CPU
Send data via a CP 441 to a printer
Carry out a reboot (warm restart) or cold restart in a remote station
Set a remote station to STOP operating state
Query the device status of a remote partner
Uncoordinated receiving of a remote device status
Supplementary information
15.6 Communication services
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