This is how one Omron controller talks to another, or to a drive, an HMI or a different brand entirely. There are two messaging worlds here: classic FINS and the EtherNet/IP CIP. Build a message and watch it resolve.
A FINS message says where (destination node), what (a service like memory-area read/write), and which (memory area + address). Assemble one and send it.
Assembled frame
FINS
Omron's native command set. It reads and writes memory areas (D, W, H…) by area + address, and it runs over Ethernet (FINS/UDP) or serial. It is the classic way for Omron gear to talk to other Omron gear and to SCADA.
CIP (EtherNet/IP)
The open standard. Implicit messaging streams I/O cyclically, and explicit messaging does on-demand reads and writes by tag. It is the route out to other brands and the wider automation world.
🌍 Crossing boundaries. FINS messages ride the network/node/unit routing you met in the Platform track; CIP uses its own route path instead. In FINS, a non-zero network number is what lets a message hop to a remote network, another site, or the cloud gateway.
You need cyclic, real-time I/O exchange with a third-party device. Which messaging fits?