Foxboro P0973CN I/A Series 4-Position Expansion Backplane

Product Overview

The P0973CN is a 4-position expansion backplane manufactured by Foxboro (Invensys) for the I/A Series and Evo distributed control systems. This modular baseplate provides mechanical mounting, backplane communication, and power distribution for up to four I/A Series modules including FCP270/FCP280 processors, FCM100E communication modules, FEM100E expansion modules, and standard FBMs. Its passive backplane design enhances system reliability by eliminating active components in the interconnection path.

Key Specifications

• System: Foxboro I/A Series / Evo
• Positions: 4 module slots
• Type: Modular expansion baseplate / backplane
• Compatible Modules: FCP280, FDC280, FCP270, FCM100Et, FCM100E, FEM100E, FBI200, FBI100, standard FBMs, 100 Series FBMs
• Fieldbus Speed: 2 Mbps (standard modules) / 268 kbps (100 Series FBMs)
• Power Connections: Primary and secondary 24 VDC
• Mounting: Vertical DIN rail mount (horizontal optional)
• Dimensions: 8.5 × 9.25 × 1.75 inches
• Weight: 1.40–1.60 lbs (0.635–0.73 kg)
• Operating Temperature: -20°C to +60°C
• Backplane Type: Passive

Features & Benefits

1. 4-Position Modular Design: Supports fault-tolerant FCP270 pairs in two positions with remaining positions for FBMs or FEM100Es.
2. Passive Backplane Architecture: No active electronics eliminates a common failure mode and extends mean time between failures.
3. Dual Power Entry: Primary and secondary 24 VDC connections support redundant power supply configurations for high-availability nodes.
4. Multi-Generation Compatibility: Accepts FCP270, FCP280, FDC280, and legacy FBM modules, protecting investment during system upgrades.
5. Keyed Module Positions: Mechanical keying prevents incorrect module insertion, protecting pins and ensuring proper addressing.
6. Redundant Bus Support: 2 Mbps HDLC redundant serial bus (Module Fieldbus) with A/B shielded twisted-pair cabling up to 60 meters.

FAQ

Q: What is the difference between P0973CN and standard baseplates?
A: The P0973CN is an expansion backplane designed to extend system capacity with 4 module positions. Standard baseplates are typically limited to single or dual-module configurations.

Q: Can I add modules to the P0973CN while the system is running?
A> Hot-swappable module support depends on the specific module type and I/A Series software revision. Consult the system manual for hot-insertion procedures.

Q: Does the backplane include a DIP switch for module identification?
A> The P0973CN is available in variants with or without baseplate identification DIP switches. Verify your specific part number suffix for switch configuration.

Installation Guide

• Mount the backplane on a 35 mm DIN rail in the control cabinet using the integrated mounting clips.
• Connect 24 VDC primary power to the power terminals. For redundancy, connect a secondary 24 VDC supply.
• Install up to four I/A Series modules into the keyed slots, pressing firmly until the ejector levers latch.
• Connect fieldbus cables between backplanes using Foxboro's standard shielded twisted-pair A/B cabling.
• Route fiber optic splitter/combiner mounting positions for redundant FCP270 pairs if applicable.
• Verify all module LEDs indicate normal status via the I/A Series operator interface.

Selection Tips

• Position Planning: The 4-position P0973CN supports two FCP270s (fault-tolerant pair) plus two FBMs/FEM100Es, or four FBMs in non-redundant configurations.
• Mounting Orientation: Vertical mounting saves horizontal cabinet width. Horizontal mounting simplifies wiring in shallow enclosures.
• Redundancy Strategy: For fault-tolerant architectures, pair redundant FCP280/FCP270 processors with redundant power supplies on dual P0973CN backplanes.
• Module Compatibility: Verify your planned modules (FCP, FCM, FBM) are supported by the P0973CN backplane revision before ordering.
• Bus Length: The 2 Mbps module fieldbus supports up to 60 meters total cable length. Plan node placement to stay within this limit.