Component Snapshot At-a-Glance

• Model: FCM2F2
• Alt. P/N: RH914YZ, P0914YZ (OEM factory part marking)
• Product Series: Foxboro I/A Series 200-Series Compact FBM baseplate platform
• Hardware Type: Fiber optic Modulebus communication extender card
• Key Feature: Full galvanic electrical isolation between control-side and remote I/O rack via fiber media
• Primary Field Use: Bridge host FCP controller rack to remote FBM I/O baseplates up to 2km multimode fiber run.

Hard-Numbers: Technical Specifications

• Protocol Support: Foxboro proprietary Modulebus backplane protocol
• Port Count: Dual ST-type multimode fiber transmit/receive ports per unit
• Baud/Data Rate: Fixed 2Mbps Modulebus fiber transmission speed
• Operating Temperature: -20°C ~ +60°C continuous cabinet ambient rating
• Isolation Rating: Full electrical isolation eliminates ground loop cross-conduction across fiber path
• Power Draw: 2.8W nominal operating power sourced from baseplate 24VDC SELV rail
• Max Fiber Reach: 2000m (2km) with standard 62.5/125μm multimode fiber cable
• Fiber Connector: ST barrel physical interface only; incompatible with SC/FC fiber terminations
• Hot-Swap Rating: Live insert/extract allowed on energized 200-series compact baseplate
• Enclosure: Extruded aluminum shell, IP20 cabinet-only installation rating

The Real-World Problem It Solves

Copper Modulebus trunk runs over long plant cable routes pick up high EMI from MCC, VFD and high-voltage feeders, triggering intermittent FBM dropouts and sporadic DCS PV freeze faults. Long copper home-runs also create large potential differences between control room and field ground grids, inducing destructive ground loop current into backplane circuits.Where you’ll typically find it:

• Refinery CDU remote field I/O racks positioned near furnace and pump banks 1~1.8km from central control room
• Coal-fired power plant boiler side economizer/air preheater remote FBM marshalling cabinets
• Offshore platform process module remote instrument racks separated from main control shelter by cable tunnel runs

Fiber media blocks all conductive noise and ground potential drift to stabilize remote I/O bus reliability.

Hardware Architecture & Under-the-Hood Logic

This card carries dedicated bus transceiver and fiber opto-electronic converter circuitry; no on-board user programmable CPU, only fixed ASIC bus translation hardware separating copper baseplane logic and optical signal domains.

1. Gold-finger rear edge connector pulls 24VDC operating power + electrical Modulebus data from host rack baseplate.
2. Onboard bus transceiver conditions incoming parallel Modulebus data stream for opto-transmitter chip conversion to modulated light pulses.
3. Light signal routes out TX ST port across multimode fiber to paired remote rack RX fiber input.
4. Remote unit opto-receiver converts incoming optical pulses back to standard electrical Modulebus digital signaling.
5. Recovered bus data feeds into remote baseplate backplane for distribution to all resident FBM analog/digital I/O modules.
6. Front-panel six discrete LEDs independently track power status, backplane bus activity, TX fiber health, RX fiber lock and overall module fault state.

Field Service Pitfalls: What Rookies Get Wrong

Mix Multimode/Singlemode Fiber Cable On ST Ports

Tech splices singlemode fiber into ST terminals to stretch run distance past 2km; mismatched core diameter causes >12dB signal attenuation, constant link blink and periodic full remote rack bus dropout.

• Quick Fix: Restrict exclusively to 62.5/125μm multimode fiber; upgrade to FCM2F10 for runs exceeding 2km total length.

Non-Paired Redundant FCM Slot Placement On Baseplate

Install spare redundant into random empty baseplate slots instead of adjacent paired slot; backplane redundancy handshake fails, standby card never auto-takes over during primary unit failure.

• Field Rule: Always mount redundant FCM set in two consecutive neighboring baseplate slots per Foxboro rack layout specs.

Force-Fit Non-ST Fiber Adapters Into Module Front Ports

Improvised SC-to-ST cheap plastic adapters crack internal port ferrules after vibration from nearby rotating equipment, creating intermittent fiber contact loss and random remote I/O lockup.

• Field Rule: Use factory-spec ST-terminated patch cords only; no third-party hybrid fiber adapters for field permanent runs.

Commercial Availability & Pricing Note

Please note: The listed price is for reference only and is not binding. Final pricing and terms are subject to negotiation based on current market conditions and availability.