Siemens SIMATIC S7-1200 - Page 845

Communication
11.2 PROFINET
S7-1200 Programmable controller
System Manual, V4.2, 09/2016, A5E02486680-AK
845
Note
TCP (data receipt with specified length)
You use the value of the LEN parameter to specify the length for th
e data receipt. The data
specified at the DATA parameter is available in the receive area as soon as the length
specified at the LEN parameter has been completely received.
Note
ISO on TCP (protocol-controlled data transfer)
With the ISO on TCP protoco
l variant, data is transferred protocol-controlled. The receive
area is defined by the LEN and DATA parameters.
BUSY, DONE, and ERROR parameters
Note
Due to the asynchronous processing of TSEND_C, you must keep the data in the sender
area consistent
until the DONE parameter or the ERROR parameter assumes the value
TRUE.
For TSEND_C, a TRUE state at the parameter DONE means that the data was sent
successfully. It does not mean that the connection partner CPU actually read the receive
buffer.
Due to the
asynchronous processing of TRCV_C, the data in the receiver area are only
consistent when parameter DONE = 1.
Table 11- 13 TSEND_C and TRCV_C instructions BUSY, DONE, and ERROR parameters
BUSY
DONE
ERROR
Description
1
0
0
The send job is being processed.
0
1
0
The send job was completed successfully.
0 0 1 The connection establishment or the send job was completed with an error. The cause
of the error is specified in the STATUS parameter.
0 0 0 No new send job was assigned.
You can check the status of the execution with the BUSY, DONE, ERROR, and STATUS
parameters. The BUSY parameter indicates the processing status. With the DONE
parameter, you can check whether or not a send job executed successfully. The ERROR
parameter is set when errors occurred during execution of TSEND_C or TRCV_C. The error
information is output at the STATUS parameter.