Siemens Simantic Net NCM for Industrial Ethernet S7 - Manual (Page 79)

SEND/RECEIVE Interface in the User Program
79
SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06
Notice
Remember that resource shortages can occur if the processing speeds on the
sender and receiver are not the same (sender faster than receiver).
The sender receives a message from the FCs if problems occur (“No resources on
the destination station”).