Siemens SIMATIC S7 System Manual page 503

Note that the S7-200 SMART does not automatically attempt to reconnect to a device after
the connection has been closed. If the remote device breaks the device connection, your
program must execute another TCP_CONNECT instruction to reconnect the device. This is
true for both active and passive connections.
Table 9- 14
Parameter
EN
Req
Active
ConnID
IPaddr1
...
IPaddr4
RemPort
LocPort
Done
Busy
Error
Status
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
Parameters of the TCP_CONNECT instruction
Declaration Data type
IN BOOL
IN BOOL
IN BOOL
IN WORD
IN BYTE
IN WORD
IN WORD
OUT BOOL
OUT BOOL
OUT BOOL
OUT BYTE
9.4 Open user communication library
Description
Enable input
The CPU starts the connect operation if Req =
TRUE. If Req = FALSE, then the outputs show
the current status of the connection.
TRUE = active connection
•
FALSE = passive connection
•
The CPU uses the Connection ID (ConnID) num-
ber to identify this connection for the other in-
structions. The possible ConnID range is 0 to
65534.
These are the four IP address octets. IPaddr1 is
the most significant byte and IPaddr4 is the least
significant byte of the IP address.
The RemPort is the port number on the remote
device. The remote port number range is 1 to
49151. Use zero for passive connections.
The LocPort is the port number on the local de-
vice. The local port number range is 1 to 49151
with some restrictions. Refer to the LocPort defi-
nition in "Parameters common to the OUC library
instructions" (Page 499).
The instruction sets the Done output when the
connect operation is complete with no errors.
The instruction sets the Busy output while the
connection operation is in progress.
The instruction sets the Error output when the
connection operation is complete with an error.
Refer to "Open user communication library in-
struction error codes" (Page 524) for further in-
formation.
The Status output shows the error code if the
instruction sets the Error output. Status is zero
(no error) if the instruction sets the Busy or Done
outputs.
Libraries
503