Logix reaches its I/O over EtherNet/IP — CIP riding on Ethernet. The lovely part: add a module to the I/O tree, and Logix creates its tags for you automatically. Set the module's RPI and you've set how often it exchanges data. Add a remote rack below and watch its tags appear.
The tree starts with just the controller and its Ethernet port. Press ➕ Add module to drop in a remote 16-point input card — and watch its tags (Conv:1:I.Data …) appear under it automatically. No addressing, no mapping table: the module's profile tells Logix exactly what tags to make. Slide the RPI to set how fast it updates.
The cyclic connection the RPI controls — module data ↔ controller tags, automatically, every RPI. This is how your I/O updates.
On-demand reads/writes via the MSG instruction (last track) — for config and occasional data, no standing connection.
A lower RPI = faster updates but more network traffic and more connections consumed (a controller has a finite budget). Tune it to the signal: 2 ms for fast interlock I/O, 50–100 ms for a temperature you read lazily. The I/O tree is your hardware config — and it writes your I/O tags as a free side-effect.
📡 Implicit (I/O) messaging — high-speed cyclic data on a standing connection, paced by the RPI. Your input/output modules and produced/consumed tags live here. Set it and forget it.
✉️ Explicit (MSG) messaging — request/response transactions you trigger (MSG instruction). For reading a drive parameter, sending a recipe, talking to a device not in your I/O tree.
Same idea as last track's produced/consumed (implicit) vs MSG (explicit) — here applied to physical I/O. EtherNet/IP carries both flavours on one wire, alongside your HMI and historian traffic.
A temperature input changes slowly and you're running low on controller connections. What RPI is sensible?