ABB RFO810 redundant fiber optic remote I/O communication module
RFO810 is a redundant FOXMAN-R fiber optic remote I/O communication module of ABB Symphony Plus (formerly INFI 90) DCS system, used for long-distance and highly reliable fiber optic data exchange between controllers and remote fieldbus units (RFUs). It is a system level communication gateway and a non-traditional control module.

1、 Core positioning and model
Model: RFO810 (complete model RFO810K01)
Series: ABB Symphony Plus (S+) DCS, FOXMAN-R Remote I/O Network
Functional positioning: Controller rack ↔ The fiber optic communication interface of remote RFU (such as RFA01) is configured with 1:1 redundancy to ensure deterministic transmission of long-distance I/O data
Ordering points: Special fiber optic connectors (ST/LC) and redundant authorization are required
2、 Hardware specifications (authoritative version)
1. Interface configuration
Fiber optic interface: 2 redundant fibers (ST/LC connectors), supporting multimode/single-mode
Backplane interface: dedicated slot (Harmony/Melody controller rack)
Status indication: LED (power, operation, fault, primary/backup, fiber link TX/RX)
2. Performance parameters
Protocol: FOXMAN-R (Dedicated Real time Fiber Optic Protocol)
Rate: 10 Mbps+(deterministic transmission, μ s level synchronization)
Distance: Multimode fiber ≤ 2 km; Single mode fiber ≤ 15 km
Topology: point-to-point, star shaped, daisy chain (connecting multiple RFUs)
Redundancy: 1:1 module redundancy+fiber link redundancy, fault free switching without disturbance
3. Physics and Environment
Size: 91.44 × 243.84 × 203.2 mm (3U rack mounted)
Weight: Approximately 0.4 kg
Power supply: 24 VDC (rack backplane power supply, ± 20%)
Temperature: -25 ℃~+60 ℃ (harsh industrial environment)
Certification: CE, UL, IECEx (explosion-proof optional)

3、 Core functions
Long distance fiber optic communication
By connecting the controller to a remote I/O station (RFU) through multi-mode/single-mode optical fiber, it is resistant to electromagnetic interference and solves the problem of long-distance (up to 15 km) I/O transmission in industrial sites.
Redundant high availability architecture
Dual module 1:1 redundancy+dual fiber optic links, automatic switching between primary and backup, switching time<1 ms, network/module failure does not affect control logic, meeting high reliability requirements.
Deterministic real-time data transmission
Specialized FOXMan-R protocol, microsecond level timestamp, ensures real-time and consistency of process data, alarms, and interlock signals, suitable for closed-loop control and safety interlock scenarios.
Multi topology flexible networking
Supporting point-to-point, star shaped, and daisy chain connections, a single module can manage multiple RFUs, adapt to different site layouts, simplify wiring and maintenance.
Hot plugging and online diagnosis
Support hot swapping, online module replacement without interrupting communication; LED status indication+remote diagnosis, quickly locate link/module faults, and reduce downtime risks.
4、 Typical applications
Industry: Process industries such as power, chemical, metallurgical, oil and gas, water treatment, etc
System: ABB Symphony Plus (S+) DCS, FOXMAN-R remote I/O network
Scene:
Long distance communication between controller and remote I/O station (RFU)
I/O connection in high electromagnetic interference environments (such as substations, frequency converter rooms)
Distributed I/O architecture for large-scale DCS systems (cross regional control)
Interlocking and protection systems with high requirements for redundant safety
5、 Difference from PNI800
RFO810: Fiber optic remote I/O communication module, controller ↔ Remote RFU, long-distance, anti-interference, redundant I/O transmission.
PNI800: PN800 Factory Network Interface Module, Upper Computer ↔ Controller, Ethernet communication, HMI/SCADA data exchange.