Honeywell ST 3000 Smart Transmitter Modules – 30756428-001

Technical Dossier

Product Details And Specifications

Honeywell ST 3000 Series Technical Notes

The Honeywell ST 3000 Smart Transmitter series is one of the most widely deployed pressure and differential pressure transmitter platforms in global heavy industry. Installed across petrochemical complexes, nuclear power stations, crude oil refineries, and large-scale chemical processing facilities, the ST 3000 platform has maintained a dominant position in distributed control system (DCS) environments — particularly within Honeywell TDC 2000, TDC 3000, and Experion PKS architectures. Its modular DSP-based signal processing design, combined with HART and DE (Digital Enhanced) protocol support, made it the reference standard for precision process measurement from the mid-1980s through the 2010s. The 30756428-001 is a direct replacement DSP Assembly for the ST 3000 transmitter body, used to restore signal processing capability without full transmitter replacement.

The Evolution of ST 3000 Architecture

The ST 3000 series was introduced by Honeywell in the mid-1980s as a successor to analog pneumatic and early electronic transmitters. The first-generation units used analog signal conditioning with 4–20 mA output and were designed for direct integration with the Honeywell TDC 2000 Highway. The introduction of the Digital Enhanced (DE) protocol in the late 1980s marked a significant architectural shift: transmitters could now communicate bidirectionally with the UCN (Universal Control Network), enabling remote configuration, self-diagnostics, and multi-variable output over a single twisted pair.

As of 2026, the ST 3000 series is in the mature/end-of-life phase. Honeywell has transitioned its transmitter portfolio to the SmartLine STD700/STG700 series. However, the installed base of ST 3000 units in legacy DCS environments remains substantial, and replacement DSP assemblies, sensor modules, and communication boards continue to be required for lifecycle extension programs.

ST 3000 Full Catalog & Functionalities (SKU List)

DSP & Electronics Assemblies

• 30756428-001: Smart Transmitter replacement DSP assembly; restores digital signal processing for ST 3000 transmitter bodies.
• 30756428-002: DSP assembly variant with extended temperature range calibration for cryogenic and high-heat process environments.
• 51196693-100: ST 3000 electronics module; primary signal conditioning board for STD924 differential pressure transmitters.
• 51196693-200: Upgraded electronics module with HART 7 protocol stack for STD924/STG924 series.
• 30731949-001: Replacement amplifier board for ST 3000 gauge pressure transmitters; compatible with STG series bodies.

Sensor & Sensing Element Modules

• 30756427-001: Differential pressure sensing capsule for ST 3000 STD series; range 0–250 inH2O.
• 30756427-002: High-static differential pressure sensing capsule; rated to 2000 psi static pressure.
• 51196694-100: Absolute pressure sensing module for STA series transmitters; range 0–3000 psia.
• 51196694-200: Gauge pressure sensing module for STG series; range 0–6000 psig.
• 30731950-001: Replacement sensor capsule for ST 3000 level transmitters; flange-mount configuration.

Communication & Protocol Adapters

• 51304485-100: DE (Digital Enhanced) protocol communication module; required for UCN/TDC 3000 integration.
• 51304485-200: HART modem adapter board for ST 3000 transmitters; enables HART 5/6 communication overlay.
• 30731951-001: Multidrop communication adapter; supports up to 15 ST 3000 devices on a single HART segment.

Power Supply & Terminal Assemblies

• 51196695-100: Intrinsically safe power conditioner for ST 3000 field installations; ATEX/IECEx certified.
• 30756429-001: Terminal block assembly for ST 3000 transmitter housing; includes surge protection and field wiring terminals.
• 51304486-100: Loop power supply module; provides regulated 24 VDC for two-wire ST 3000 transmitter loops.

Quality Control for the ST 3000 Range

ST 3000 DSP assemblies and electronics modules require functional validation beyond visual inspection due to the complexity of their analog front-end circuitry and digital communication stacks. DriveKNMS applies a structured test protocol to all ST 3000 components prior to dispatch:

• Power-on functional test: board energized at rated supply voltage (12–42.4 VDC loop); current draw and output signal verified against factory specification.
• DE protocol handshake test: communication module tested against a live UCN segment emulator to confirm bidirectional data exchange and device address assignment.
• HART communication test: HART 5/6/7 command set executed using a calibrated HART communicator; PV, SV, TV, QV outputs verified.
• Calibration verification: zero and span calibration checked against NIST-traceable pressure standards; deviation logged and reported with each unit.
• Environmental stress screening: boards subjected to thermal cycling (−20°C to +70°C) to identify latent solder joint or component failures prior to shipment.
• Cosmetic and mechanical inspection: connector pins, housing integrity, and label legibility verified; any physical anomalies documented in the test record.