IoT Protocols in Industry
"Industrial, digital bus used for real-time distributed control."
- Mainly used in manufacturing (assembly lines, process control, etc.)
- Connects instruments in the shop-floor
- Allows different topologies (daisy-chain, tree, etc.)
- Controllers where originally connected through serial (just picture the cable salads); a fieldbus solves that issue
- Cost-effective (less cables, easier maintenance)
- Modbus RTU (serial) (published in 1979!)
- Modbus TCP (Ethernet)
- Profibus (serial)
- Profinet
- CAN (a vehicle bus, in reality)
- Bitbus
- EtherCAT
- DeviceNET
- BACnet (Although I wouldn't call it a fielbus...)
- And many, many more...
- Not to be confused with a PLC (Programmable Logic Controller)
- They often support different fieldbuses by default
- Easily expandable (new I/O modules can be attached, motor drivers, etc.)
- Most of them run an OS (and it's possible to create custom images)
- Manufacturers provide SDKs in different languages
- Connectivity (at least 2x network interfaces, WiFi, 3G/LTE failover, serial, etc.)
- More and more have built-in HTTP APIs
- Most of them integrate web servers for configuration, HMIs or SCADA functionalities
- They may replace the proprietary automation software suites
"IO-Link is the first standardised IO technology worldwide (IEC 61131-9) for the communication with sensors and actuators. IO-Link is no fieldbus but the further development of the existing, tried-and-tested connection technology."
- 3-wire connections
- Smart sensors: they work out-of-the-box, and they "identify" themselves
- Descriptive files that include information of the manufacturer, the type, and the calibration
- Sensors can be replaced, and the calibration and specs file updated remotely
- IO-Link masters support different fieldbus and Industrial Ethernet standards
