Siemens SIMATIC S7 System Manual page 221

Table 7- 9
Byte
offset
A/P: Active/Passive selection (1 = Active, 0 = Passive)
1
Connection Type: The Connection Type informs the TCON instruction of the desired type of con-
2
nection: UDP = 19 and TCP = 11
Remote IP address: This is the IP address of the remote device in the case of an active connec-
3
tion. You should set the Remote IP Address to 0.0.0.0 for UDP connections. The IP address must
be different than that of the local CPU and cannot be a multicast or broadcast address. Since the
S7-200 SMART supports routing, the IP address may be on a different subnet than the local CPU.
If you set the IP address for a passive (server) connection, then the CPU only accepts a connec-
tion from the specified IP address. If you set the IP address to 0.0.0.0 for a passive connection, the
CPU accepts a connection from any IP address.
Remote Port: This is the port number in the remote device. You do not use the remote port num-
4
ber for UDP or passive connections, and you should set the Remote Port to zero.
Local Port: This is the port number for the connection in the local CPU.
5
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
Definition of TCON instruction TABLE parameter structure for UDP and TCP
Bit 7 Bit 6
0 D A
1 A/P
1
2
3
4
5
6
7
8
9
10
11
12
Bit 5 Bit 4 Bit 3
E
Connection ID
(2 bytes)
Connection Type
Remote
IP
Address
3
Remote port
Local port
5
Program instructions
7.3 Communication
Bit 2 Bit 1
Error code (5 bits)
2
4
Bit 0
REQ
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