Technical data

Table Of Contents
Open Communication via Industrial Ethernet
System Software for S7-300/400 System and Standard Functions - Volume 2/2
23-26
A5E00739858-01
23.9 Sending Data via TCP native and ISO on TCP with
FB 63 "TSEND"
Description
FB 63 "TSEND" sends data over an existing communications connection.
Function
FB 63 "TSEND" is an asynchronously functioning FB, which means that its
processing extends over several FB calls. To start sending data, call FB 63 with
REQ = 1.
The job status is indicated at the output parameters BUSY and STATUS. STATUS
corresponds to the RET_VAL output parameter of asynchronously functioning
SFCs (see also Meaning of the Parameters REQ, RET_VAL and BUSY with
Asynchronous SFCs).
The following table shows the relationships between BUSY, DONE and ERROR.
Using this table, you can determine the current status of FB 63 or when the
establishment of the connection is complete.
BUSY DONE ERROR Description
TRUE irrelevant irrelevant The job is being processed.
FALSE TRUE FALSE The job was completed successfully.
FALSE FALSE TRUE The job was ended with an error. The cause of the error can be
found in the STATUS parameter.
FALSE FALSE FALSE The FB was not assigned a (new) job.
Note
Due to the asynchronous function of FB 63 "TSEND", you must keep the data in
the sender area consistent until the DONE parameter or the ERROR parameter
assumes the value TRUE.