4256A64G05 is the legacy original drawing part number of Westinghouse, while 3A99163G05 is Emerson’s official interchangeable spare part number. These two part numbers correspond to the same fifth-generation flagship RTD temperature acquisition module, which is matched with 4256A25 series MRC main remote control boards and 4256A26 remote expansion boards for Ovation WDPF DCS remote I/O racks. It features full plug-and-play backward compatibility with G01/G02/G03/G04 earlier versions, and no system configuration or program modification is required during replacement.

This module is dedicated to high-precision collection of PT100 and PT1000 resistance temperature detector signals in harsh industrial environments. It adopts ultra-low-noise front-end filter circuits, temperature-compensated ultra-stable constant current excitation, multi-stage reinforced galvanic isolation and a brand-new full-range adaptive temperature conversion algorithm, transmitting ultra-stable and high-repeatability digital temperature data to the DCS main controller. Compared with previous G01–G04 revisions, G05 is equipped with premium low-drift sampling chips to greatly suppress zero drift and gain drift under wide ambient temperature fluctuations. It carries 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 to achieve 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 each signal channel to completely avoid cross-channel signal crosstalk.

The circuit board is made of multi-layer high-temperature resistant FR-4 industrial PCB with a 360° fully enclosed electromagnetic shielding layout. Each channel realizes 1000V AC/DC galvanic isolation between field wiring terminals and internal logic circuits, which can effectively block 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 integrates multi-layer comprehensive 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.

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