Industrial Engineer · phase 5 of 16
RPI
Requested Packet Interval, the configured rate at which a CIP I/O connection requests data updates.
The Explain card
- Plain English
- The requested packet interval is how often a controller asks a device to exchange implicit data. It is set per connection, in milliseconds.
- Example
- A safety I/O block is set to a 10 millisecond RPI, a temperature module to 250 milliseconds. The controller schedules both and the network carries them at those rates.
- Why it matters
- Faster RPIs mean fresher data and more traffic, and a rack full of devices at 2 milliseconds saturates a controller's connection budget. The default is rarely right for everything, so set each RPI to what the process actually needs.
- Hook
- How often you want to hear from it.
Where it sits in the deck
Phase 5: PLC Industrial Communications
The protocols that let controllers, drives and operator panels talk, plus the addressing and description files that make them agree on what was said.
