2 Engineering
2.7.3
Communication program SIMATIC S5
Overview
The following blocks contain the communication program of the S5-CPU. In this
scenario, the S5 sends and receives data via an active ISO-on-TCP connection.
The connection is established from the SIMATIC S5.
OB 21
Startup
OB 22
Startup
OB 1
Main
Function
Via the connection actively established by the SIMATIC S5, data are sent
bidirectionally with a count value to the S7-1500 every second. From there, this
count value is mirrored and sent back. After the data have been received, this
count value is increased by +1 and sent again.
In case of the SIMATIC S5 CPU being restarted, a deletion identifier is sent to the
S7-1500 and the count value is reset.
Description of the blocks
The following blocks contain the communication program of the S5-CPU.
Table 2-21
Block
OB 21
OB 22
OB 1
Ethernet Communication (ISO on TCP) between SIMATIC S5 and
SIMATIC S7-1500 Controllers
Entry-ID: 109482475,
V1.2,
FB31
SEND_ALL
User
blocks
Symbol
Startup_OB21
Startup_OB22
Main
07/2019
HTB
SYNCHRON
HTB SEND
SEND_DB
HTB RECV
HTB
HTB
RECV_ALL
Handling
Data blocks
blocks
Description
Startup OB (restart/warm start)
Startup OB (network/cold start)
User program call of FB 33 and of the HTBs
SEND/RECEIVE ALL
RECV_DB
70