Emerson 4256A64G05 3A99163G05 Ovation DCS Control Card
June 10, 2026

Emerson 4256A64G05 3A99163G05 Ovation DCS Control Card

4256A64G05 is the legacy original part number from Westinghouse, and 3A99163G05 is Emerson’s official interchangeable aftermarket spare part number; both part numbers represent the identical fifth-generation flagship RTD temperature acquisition module. It matches 4256A25 series MRC main remote control boards and 4256A26 remote expansion boards for Ovation WDPF DCS remote I/O racks, and maintains full plug-and-play backward compatibility with G01/G02/G03/G04 earlier versions, requiring no system configuration or program modification during card replacement.

Description

This module is designed for high-precision collection of PT100 and PT1000 resistance temperature detector signals in harsh industrial environments. It integrates ultra-low-noise front-end filter circuits, temperature-compensated ultra-stable constant current excitation, multi-stage reinforced galvanic isolation and brand-new full-range adaptive temperature conversion algorithms, outputting ultra-stable, high-repeatability digital temperature data to the DCS main controller. Compared with previous G01–G04 revisions, G05 adopts premium low-drift sampling chips to drastically suppress zero and gain drift under wide ambient temperature fluctuations. It equips an upgraded self-adaptive lead resistance compensation algorithm to eliminate measurement errors caused by ultra-long field transmission cables, and adds multi-level EMI suppression circuits for stronger anti-interference performance under complex heavy-industry electromagnetic conditions. The board supports 2-wire, 3-wire and 4-wire RTD wiring modes, with fully independent isolation loops for every signal channel to completely eliminate cross-channel signal crosstalk.
The circuit board adopts multi-layer high-temperature resistant FR-4 industrial PCB with 360° fully enclosed electromagnetic shielding layout. Each channel provides 1000V AC/DC galvanic isolation between field wiring terminals and internal logic circuits, effectively blocking severe electromagnetic noise generated by inverters, high-voltage switchgears, large rotating machinery and arc equipment in thermal power, petrochemical, metallurgical and other heavy industrial sites. Every finished unit passes complete full-lifecycle factory reliability verification, including 72-hour high-low temperature cyclic aging test, full-channel ultra-precision temperature calibration, long-duration full-load MRC Link bus communication burn-in, and comprehensive sensor open-circuit/short-circuit fault simulation testing. It supports single-slot hot-swappable installation without shutting down the entire DCS system, and embeds multi-layer integrated hardware protection functions: surge suppression, overvoltage protection, overcurrent protection, reverse polarity prevention and short-circuit protection. Independent LED diagnostic indicators separately display power supply status, bus communication link status and single-channel sensor fault alarms for rapid on-site fault localization, significantly improving long-term measurement accuracy and continuous operation stability for critical industrial process temperature monitoring.

Technical Specifications

  1. PCB Substrate: Multi-layer high heat-resistant FR-4 industrial printed circuit board

  2. Operating Temperature Range: -25℃ ~ +75℃

  3. Storage Humidity: 5% ~ 90% RH, non-condensing

  4. EMC Compliance: Industrial Class II, CE certified, compliant with EN 61000 series anti-interference standards

  5. Communication Bus: Dedicated MRC Link differential bus for Ovation remote I/O racks

  6. Channel Isolation Withstand Voltage: 1000V AC/DC galvanic isolation per independent signal channel

  7. Supported Sensors: PT100, PT1000 RTD; compatible with 2/3/4-wire wiring with full-range adaptive lead resistance compensation

  8. On-board Integrated Protections: Surge suppression, overvoltage protection, overcurrent protection, reverse polarity protection, short-circuit protection

  9. Installation Mode: Single-slot hot-swappable plug-in module for standard Ovation DCS rack backplane

  10. Quality Warranty: Genuine original Emerson/Westinghouse product, supplied with independent factory inspection test report, 12-month official warranty

Application Fields

Medium and super-large thermal power plant Ovation WDPF distributed control systems, multi-unit integrated petrochemical process temperature acquisition cabinets, full-process furnace, pipeline and core equipment temperature monitoring stations for metallurgical factories, multi-station automatic control systems of large municipal wastewater treatment plants, whole-plant production line temperature signal acquisition racks for pulp & paper factories, multi-rack redundant central control rooms of traditional heavy industry, temperature parameter remote monitoring automation platforms for energy & chemical continuous production lines, centralized DCS monitoring control systems for large-scale distributed energy storage power stations


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