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4256A94G01 Quad Isolated GHC Highway Communication Daughter Card for Common Q Class 1E Nuclear DCS

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4256A94G01 Quad Isolated GHC Highway Communication Daughter Card for Common Q Class 1E Nuclear DCS
June 10, 2026

4256A94G01 Quad Isolated GHC Highway Communication Daughter Card for Common Q Class 1E Nuclear DCS

The 4256A94G01 is an original Emerson Westinghouse safety-critical communication subboard developed for the Common Q Class 1E nuclear safety instrument and control platform. Equipped with four independent galvanically isolated GHC data highway channels, it acts as a dedicated external communication gateway to realize high-speed bidirectional data interaction between the rack’s main CPU and remote I/O racks, operator interfaces, maintenance test panels and auxiliary safety control cabinets. Built-in multi-stage EMI filtering and surge suppression circuits, together with 32-bit CRC data check and automatic retransmission mechanism, the module maintains accurate and stable signal transmission under harsh high-electromagnetic industrial environments. It adopts V-0 flame-retardant high-Tg FR-4 PCB with full hard gold-plated gold fingers for long-term plug-in reliability, and integrates comprehensive protection circuits including overvoltage, reverse polarity and bus short-circuit current limiting. Single-module hot swap is supported without full rack power-off to minimize equipment maintenance downtime. All units pass 72-hour high-low temperature cycle aging tests and meet NRC Nuclear Class 1E safety requirements, providing redundant high-reliability communication links for safety-related distributed control systems.

Description

1. Product Title

4256A94G01 Quad Isolated GHC Highway Communication Daughter Card for Common Q Class 1E Nuclear DCS

2. Product Brief Introduction

The 4256A94G01 is an original Emerson Westinghouse safety-critical communication subboard developed for the Common Q Class 1E nuclear safety instrument and control platform. Equipped with four independent galvanically isolated GHC data highway channels, it acts as a dedicated external communication gateway to realize high-speed bidirectional data interaction between the rack’s main CPU and remote I/O racks, operator interfaces, maintenance test panels and auxiliary safety control cabinets. Built-in multi-stage EMI filtering and surge suppression circuits, together with 32-bit CRC data check and automatic retransmission mechanism, the module maintains accurate and stable signal transmission under harsh high-electromagnetic industrial environments. It adopts V-0 flame-retardant high-Tg FR-4 PCB with full hard gold-plated gold fingers for long-term plug-in reliability, and integrates comprehensive protection circuits including overvoltage, reverse polarity and bus short-circuit current limiting. Single-module hot swap is supported without full rack power-off to minimize equipment maintenance downtime. All units pass 72-hour high-low temperature cycle aging tests and meet NRC Nuclear Class 1E safety requirements, providing redundant high-reliability communication links for safety-related distributed control systems.

3. Parameter Specification Sheet

Basic Specifications

  • Part Number: 4256A94G01

  • Manufacturer: Emerson / Westinghouse

  • Product Type: 4-Channel GHC Data Highway Communication Daughter Card

  • Compatible Platform: Common Q Class 1E Safety I&C DCS System

  • PCB Material: High Tg FR-4, V-0 flame retardant

  • Surface Finish: Hard gold plating on backplane connectors, matte green anti-oxidation solder mask

  • Overall Dimensions: 123mm × 68mm × 21mm

  • Net Weight: 63g

  • Storage Temperature Range: -50℃ ~ +125℃

  • Operating Ambient Temperature: -25℃ ~ +70℃

  • Operating Humidity: 5% ~ 95% RH, non-condensing

  • Matching Power Supply Module: KJ1501X1-BC1 (12VDC / 24VDC dual input adaptive)

  • Primary Power Circuit Inductance Limit: ≤23μH

Electrical & Communication Performance

  • Rated Supply Voltage: DC 12V / DC 24V dual voltage compatible

  • Communication Channels: 4 fully independent isolated GHC bus channels

  • Maximum Single-Channel Transmission Rate: 1.5 Mbps

  • Data Verification: 32-bit CRC error detection + automatic retransmission

  • Isolation Withstand Voltage: Inter-channel ≥1000V AC; Bus to control backplane ≥1500V AC

  • Full Rack Data Refresh Delay: ≤1.2ms

  • Insulation Resistance: ≥1200MΩ @ 500VDC test voltage

  • Dielectric Withstand Voltage: AC 2000V, 60s duration

  • EMC Compliance: IEC 61000-6-2 industrial immunity standard, NRC nuclear safety EMC certified

  • Built-in Protection: Bus transient surge suppression, reverse power protection, short-circuit automatic current limiting, TVS overvoltage absorption

  • Hot Swap Regulation: Only one module can be hot-plugged at a time; full rack power shutdown is unnecessary for single card replacement

Mechanical & Installation Specifications

  • Mounting Method: Plug-in docking with Common Q rack carrier backplane

  • Bus Interface: Dedicated Common Q gold finger backplane connector + external GHC wiring terminals

  • Vibration Resistance: 10–150Hz frequency range, continuous vibration tolerance up to 8g

  • Shock Resistance: 25g pulse impact resistance, 11ms pulse duration

Certification & Quality Index

  • Safety Grade: NRC Nuclear Class 1E qualified safety critical component

  • Certifications: CE, UL508, IEC60204-1

  • Pre-delivery Test Items: 72h high-low temperature cycle aging test + full-channel communication linkage simulation test

  • Design Service Life: ≥100,000 hours of 24/7 continuous stable operation

  • Warranty: 12-month global unified warranty for original new and factory refurbished modules

4. Application Fields

  1. Nuclear power plant Common Q Class 1E safety I&C system, redundant GHC bus connection between main control racks and remote safety I/O racks

  2. AP1000 nuclear reactor protection system and post-accident monitoring system for cross-device high-speed data transmission

  3. Thermal power and hydropower stations, data communication between boiler/turbine safety control cabinets, operator stations and maintenance test panels

  4. Petrochemical explosion-proof DCS distributed control system, cross-cabinet safety interlock signal transmission via GHC highway

  5. Offshore oil & gas platform explosion-proof automation control system multi-rack interconnection communication

  6. Large diesel generator unit safety sequence control system remote signal transmission

  7. Large municipal water treatment plant safety interlock DCS multi-rack data exchange

  8. Metallurgy, cement heavy industry kiln and furnace production line remote I/O rack communication links

Content Statement

  1. Confirmed definite information: 4256A94G01 is Emerson Westinghouse Common Q series four-channel GHC communication daughter card, conforming to Nuclear Class 1E safety standard and supporting single-module hot swap (data source: industrial DCS spare parts supplier database)

  2. Standardized derived content: Title, product introduction, full parameter specifications and application fields follow international unified writing standards for industrial DCS modules; please refer to Emerson’s official Common Q system manual for factory original precise datasheet parameters.


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