Communication Protocols; Rt And Irt - Omron PROFINET NX-PNC202 User Manual

8 PROFINET Communications
8-1

Communication protocols

PROFINET uses Ethernet and TCP, UDP and IP as basis for the communication between the devices.
8-1-1

RT and IRT

The TCP/IP and UDP/IP communication protocols apply a considerable amount of control overhead
which will slow down data transmission speed which is required for PROFINET applications. To
facilitate Real-Time capabilities for data exchange, the PROFINET uses a specific protocol of
Real-Time (RT) Communication. This protocol cancels some of the flow control and addressing in
comparison with the TCP/IP and UDP/IP.
For the prioritized transmission of RT-frames, Real-Time communication uses the VLAN tag as
defined in IEEE 802.1Q.
8 - 2
NX-series PROFINET Coupler Unit User's Manual (W623)