PROFINET vs EtherNet/IP vs EtherCAT: a selection guide
Compare PROFINET, EtherNet/IP, and EtherCAT on synchronization, cycle time, topology, tooling, and ecosystem — and pick the protocol your plant can live with.
Requested Packet Interval (RPI)
CIP connection update rate.
How often an EtherNet/IP implicit connection exchanges data (e.g. every 10 ms). Faster RPIs load the network and controllers; set the slowest rate the application tolerates.
See also: EtherNet/IP · Determinism
Use the concept: Subnet calculator · Modbus RTU CRC & frame helper · Modbus register decoder & byte-order check
In depth
EtherNet/IP and CIP messaging: explicit vs implicit, RPI, and assemblies
How the Common Industrial Protocol really moves data — connected and unconnected messaging, produced/consumed tags, and sizing connection loads.
Modbus polling and timeout budget: calculate the slow path
Estimate serial transaction time, include silent intervals and device response, and prevent offline devices from consuming the entire polling cycle.