Open User Communication Library Instructions; Tcp_Connect Instruction - Siemens SIMATIC S7 System Manual

● RemTsap: The RemTsap (remote Transport Service Access Point (TSAP)) parameter is
a pointer to an S7-200 SMART string data type. You can only use the RemTsap
parameter for the ISO-on-TCP protocol. The remote TSAP string serves the same
purpose as a port number in routing the message to the proper connection.
The rules for the RemTsap are as follows:
– The TSAP is an S7-200 SMART string data type (a length byte followed by the
– The TSAP string must be at least 2 characters and no more than 16 characters.
● LocTsap: The LocTsap (local Transport Service Access Point (TSAP)) parameter is a
pointer to an S7-200 SMART string data type. You can only use the local TSAP
parameter for the ISO-on-TCP protocol. The local TSAP string serves the same purpose
as a port number in routing the message to the proper connection.
The rules for the LocTsap are as follows:
– The TSAP is an S7-200 SMART string data type (a length byte followed by the
– The TSAP string must be at least 2 characters and no more than 16 characters.
– If the TSAP is 2 characters, the first character must be a hexadecimal "E0".
– The TSAP cannot start with the string "SIMATIC-".
9.4.2

Open user communication library instructions

9.4.2.1

TCP_CONNECT instruction

The TCP_CONNECT instruction creates a connection to another device using the TCP
protocol.
LAD/FBD STL
TCP_CONNECT Req, Active,
ConnID, IPaddr1, IPaddr2,
IPaddr3, IPaddr4, RemPort,
LocPort, Done, Busy, Er-
ror, Status
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
characters).
characters).
Description
The TCP_CONNECT creates a TCP communications connection
from the CPU to a communication partner.
9.4 Open user communication library
Libraries
501