Technical data

Table Of Contents
Open Communication via Industrial Ethernet
System Software for S7-300/400 System and Standard Functions - Volume 2/2
23-36
A5E00739858-01
23.12 Receiving Data via UDP with FB 68 "TURCV"
Description
FB 68 "TURCV" receives data via UDP. After successful completion of FB 68
"TURCV" the parameter ADDR will show you the address of the remote partner
(the sender).
Function
FB 68 "TURCV" is an asynchronously functioning FB, which means that its
processing extends over several FB calls. To start sending data, call FB 68 with
REQ = 1.
The job status is indicated at the output parameters RET_VAL and BUSY.
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 68 or when the
receiving process 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 68 "TURCV", the data in the receiver area
are only consistent when the NDR parameter assumes the value TRUE.