Foxboro FBM22 Product Description

The Foxboro FBM22 (also referenced as P0900HS) is a Remote Manual Unit (RMU) Interface Module within the Foxboro I/A Series Distributed Control System (DCS) portfolio, engineered by Foxboro (Schneider Electric) to serve as a compact, high-reliability bridge between the DCS and local manual control stations or field operator interfaces. Designed for 1 analog input (1AI) / 1 analog output (1AO) functionality, it delivers precise, galvanically isolated signal conversion for 4–20 mA or 0–5 VDC analog signals, enabling seamless integration of manual control panels, local indicators, and auxiliary field devices into the I/A Series or Foxboro Evo™ DCS ecosystem. Its rugged, space-saving design, hot-swap capability, and wide environmental tolerance make it ideal for process industries requiring reliable local operator interaction and signal translation in harsh conditions.

The FBM22 integrates one isolated analog input channel and one isolated analog output channel, providing electrical separation between field circuits and the DCS backplane to eliminate ground loops, electrical crosstalk, and transient voltage damage. The input channel accepts user-selectable 0–20 mA current or 0–5 VDC voltage signals, while the output channel generates 0–20 mA analog signals, supporting direct connection to manual control stations, local indicators, recorders, or small actuators.

High-precision signal processing ensures ±0.1% full-scale accuracy for both input and output, with a fast response time of <1 ms to capture rapid signal changes and ensure timely control actions. Galvanic isolation rating of 500 V AC (1 minute) protects the module and DCS from field-side electrical faults, enhancing system safety and reliability.

Communication with the DCS controller (FCP/ZCP) or fieldbus communication module (FCM) uses a redundant 2 Mbps HDLC fieldbus with automatic A/B path failover, preventing data loss during communication path disruptions. The module supports hot-swap capability, allowing online replacement without shutting down the DCS or interrupting process control—critical for high-availability applications.

Rugged construction includes an extruded aluminum enclosure and conformal-coated printed circuit board (PCB), rated to withstand dust, moisture, vibration, and wide temperature fluctuations. Front-panel LED indicators provide clear visual status for power, communication, and channel activity, enabling quick on-site troubleshooting without specialized tools.

Manufacturer: Foxboro (Schneider Electric)Compatible Systems: Foxboro I/A Series DCS, Foxboro Evo™ DCSModel Number: FBM22 (Part Number: P0900HS)Channel Configuration: 1 isolated analog input (AI), 1 isolated analog output (AO)Input Signal Types: 0–20 mA DC (current), 0–5 V DC (voltage), user-selectableOutput Signal Type: 0–20 mA DC (current)Accuracy: ±0.1% full scale (both AI and AO)Response Time: <1 msIsolation: 500 V AC for 1 minute (field-to-logic isolation)Communication: Redundant 2 Mbps HDLC fieldbus, A/B path redundancy with automatic failoverPower Supply: 24 V DC (operating range: 18–32 V DC); max power consumption 3 WOperating Temperature: –20 °C to +60 °C (–4 °F to +140 °F)Storage Temperature: –40 °C to +85 °C (–40 °F to +185 °F)Relative Humidity: 5%–95% non-condensingAltitude: –300 m to +3,000 m (–1,000 ft to +10,000 ft)Enclosure: Extruded aluminum, conformal-coated PCB; IP20 ratingDimensions: Approximately 102 mm × 45 mm × 104 mm (4.0 in × 1.8 in × 4.1 in)Weight: 0.3 kg (0.66 lb)Certifications: CE, UL, CSA, ATEX, RoHS compliant

The FBM22 is widely deployed across process industries requiring local manual control interface integration and analog signal translation between field devices and the DCS. In chemical and petrochemical plants, it connects DCS controllers to local manual control stations for reactor feed valves, distillation column level controls, or pipeline pressure regulators, enabling operators to switch between automatic DCS control and manual on-site adjustment without system shutdown.

In oil and gas facilities—including refineries, offshore platforms, and gas processing plants—it interfaces with local indicators, recorders, and small actuators for flow, pressure, and level monitoring, supporting emergency manual override for critical process loops and ensuring safe, efficient hydrocarbon production.

In power generation plants, the FBM22 links DCS systems to local control panels for boiler auxiliary valves, turbine auxiliary actuators, or cooling system regulators, providing reliable manual control backup and precise signal conversion for critical power plant components. In water and wastewater treatment plants, it connects DCS controllers to local manual stations for dosing pumps, gate valves, and aeration blowers, enabling on-site operator adjustment and ensuring accurate process control.

In pharmaceutical, food and beverage, and fine chemical industries, the FBM22’s high accuracy, isolation, and compliance with international standards make it suitable for regulated processes requiring reliable manual control and signal integrity, while its compact size and hot-swap capability minimize downtime in space-constrained cabinets.

The FBM22 installs on standard DIN rails in Foxboro I/A Series or Evo™ DCS cabinets, mounting on a dedicated I/A Series baseplate for power distribution and redundant fieldbus communication with the DCS backplane. Field wiring connects to a compatible termination assembly (TA), which provides surge protection, signal conditioning, and field device connection points, supporting both local and remote wiring configurations.

Standard shielded industrial cables are recommended for field wiring, with proper grounding to optimize noise immunity and ensure reliable signal transmission. The analog input channel wires to a manual control station or local sensor, while the analog output channel connects to a local indicator, recorder, or actuator—loop power is supplied via the TA or external 24 V DC sources as required.

System configuration is performed via Foxboro DCS software, enabling users to select input signal types (current/voltage), calibrate input/output ranges, and configure redundant communication modes. The module is plug-and-play compatible with existing Foxboro systems, requiring minimal on-site setup and supporting hot-swap replacement for maintenance without system shutdown. It integrates seamlessly with other I/A Series modules, forming a unified, scalable process control solution for both automatic and manual control applications.

Routine maintenance for the FBM22 includes visual inspection of the aluminum enclosure for physical damage, dust accumulation, or loose connections, and verification of front-panel LED indicators for normal power, communication, and channel operation. Periodic testing of input/output accuracy, loop resistance, and communication integrity is recommended, especially in high-vibration, corrosive, or strong electromagnetic interference environments. The conformal coating on the PCB protects against moisture and dust, reducing cleaning frequency.

Faulty modules can be repaired by authorized Schneider Electric service providers, with standard and expedited repair options available for critical applications. The FBM22 comes with a 12-month standard warranty against manufacturing defects, with extended warranty options available for long-term operational reliability. For redundant communication configurations, periodic testing of path failover functionality is recommended to ensure fault tolerance readiness.