Siemens SIMATIC S7-1200 Reference Manual page 63

Basic instructions
The following pages provide an overview of the details and usage of important functions of open communication and S7
communication.
Open communication
Definition: Open exchange of data via
controllers and third-party devices. Example of suitable interfaces:
• Integrated PROFINET/Industrial Ethernet interfaces of controllers
• PROFINET/Industrial Ethernet interfaces of communication modules
Due to the open and flexible communication, the size of a sent data package is not automatically known to the receiver. TCP
or ISO-on-TCP ensures the arrival of the data at the receiver through a transport acknowledgment. To ensure that the data
has arrived completely in the application of the receiver, you must determine:
1. Determine the size of the data package in the sender.
2. Transfer the size of the data package to the receiver.
3. Evaluate the information in the receiver.
A5E33284667-AA
Extended instructions
PROFINET/Industrial Ethernet
Technology
between SIMATIC controllers or between SIMATIC
Communication
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