Preparing the published article.
Fieldbus, IO and Network Terms
Interface vocabulary is where integration projects start.
Common terms
| Term | Meaning |
|---|---|
| Discrete IO | Individual on or off signals |
| Analog signal | A continuous value such as pressure or speed |
| Fieldbus | A network for devices in a machine |
| Industrial Ethernet | Ethernet-based protocols for controllers and robots |
| Cyclic and acyclic data | Continuous exchanges versus on-demand messages |
Why the words matter
- Cycle time and determinism affect real-time behaviour.
- Safety data often uses a different protocol from standard data.
- Spare IO and spare addresses prevent future rework.
Protocol support varies by controller. Confirm with the equipment supplier before standardising.

