Component Snapshot At-a-Glance
- Model:
- Alt. P/N: No factory alternate part number; marketed under NCNI formal designation, no direct cross OEM substitute
- Product Series: Foxboro I/A Series DCS, NCNI (Nodebus Communication Interface) network family
- Hardware Type: Rack-mount backplane plug-in gateway module, onboard dedicated CPU for protocol translation
- Key Feature: Native bidirectional conversion between proprietary I/A Nodebus and standard industrial Ethernet
- Primary Field Use: Bridge rack-based control processors to plant SCADA/HMI via Ethernet inside DCS main control cabinets
Hard-Numbers: Technical Specifications
- Protocol Support: I/A Nodebus proprietary bus, TCP/IP, DECnet, Modbus TCP for cross-system data handoff
- Port Count: Dual 10/100Mbps RJ45 Ethernet ports + 1 internal backplane Nodebus edge connector
- Baud/Data Rate: Nodebus fixed 268.75kbps; Ethernet auto-negotiate 10/100Mbps max throughput
- Operating Temperature: 0°C ~ +60°C continuous cabinet runtime; -40°C ~ +85°C non-operational storage
- Isolation Rating: 500V isolation between backplane Nodebus circuit and external Ethernet RJ45 ports
- Power Draw: 2.4W typical consumption; 18–36VDC rack backplane sourced power input
- Physical Dimension: 70×268×107mm; unit net weight 2.22kg
- Humidity Rating: 5%–95% RH non-condensing cabinet ambient only
The Real-World Problem It Solves
Legacy I/A DCS racks lacked native Ethernet output; techs previously deployed external third-party protocol converters prone to vibration dropouts and unmonitored comms loss mid-run.Where you’ll typically find it:
- Coal-fired power plant main DCS rack: Link boiler control nodes to plant central SCADA historian server
- Refinery crude distillation cabinet: Connect process controllers to offsite remote HMI monitoring stations
- Pulp & paper mill dryer line control rack: Bridge local Nodebus nodes to factory ERP data collection networkSingle rack-mounted NCNI eliminates messy external converter wiring and cuts unplanned comms downtime from mismatched third-party hardware.
Hardware Architecture & Under-the-Hood Logic
This is active processing hardware with dedicated onboard microcontroller; PCB splits into isolated backplane Nodebus section and front-panel Ethernet transceiver zone to block cross-domain surge damage.
- Backplane edge connector pulls Nodebus process data off rack shared bus into module’s internal receive buffer
- Onboard CPU parses proprietary Foxboro Nodebus frame formatting and repackages payload into standard TCP/IP packets
- Dual RJ45 Ethernet ports route reformatted data outward to plant LAN; dual ports enable redundant LAN failover routing
- Inbound Ethernet SCADA commands reverse through CPU protocol translation before passing back onto rack Nodebus
- Onboard nonvolatile flash stores fixed firmware; no field user configurable logic loaded locally on module
Field Service Pitfalls: What Rookies Get Wrong
Improper Unshielded CAT5 Cabling for RJ45 PortsNew technicians run unshielded regular Ethernet alongside VFD power wiring; cabinet induced EMI triggers intermittent CRC errors and random port dropouts.Field Rule: Deploy fully shielded CAT6 cable for all module Ethernet runs, terminate cable shield at cabinet earth ground only one end.
Forced Hot-Swap Without Nodebus LockoutApprentices pull or seat live while rack powered; inrush surge fries backplane Nodebus transceiver IC and crashes entire rack segment communication.Quick Fix: Toggle rack segment power down or set maintenance mode before removing/installing any NCNI module.
Blocked Side Vent Slots Restricting Passive CoolingInstallers stack adjacent modules flush against side ventilation grilles; trapped heat overheats onboard CPU and triggers recurring random module fault codes.Field Rule: Reserve minimum 8mm side clearance between rack modules to maintain natural cabinet airflow across vent openings.
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.
