Hello,
the first thing you should do: evaltuate the outputs in your program.

How do you evaluate the status of system blocks in STEP 7 (TIA Portal)?

Regards,
Kaulquappe

hi,

the state 7002 is saying it is an intermediate call.

Have you checked that the Data you receive are really what you expect?

Do the other outputs(NDR, Length) act like expected?

Try to use a bigger buffer.

And also do an error/status-evaltuation and save the status when error=true.

hope this helps,

regards,