Honeywell TDC 3000 / LCN Modules – 51403519-160 K4LCN-16 Memory Processor Module

Technical Dossier

Product Details And Specifications

Honeywell TDC 3000 / LCN Series: Comprehensive Module Range and Technical Overview

The Honeywell TDC 3000 (Total Distributed Control) platform, built around the Local Control Network (LCN) architecture, is one of the most widely deployed Distributed Control Systems in global heavy industry. Installations span petrochemical complexes, crude oil refineries, nuclear power generation facilities, pulp and paper mills, and large-scale chemical processing plants. The LCN backbone operates at 5 Mbit/s and supports up to 64 nodes per network segment, providing deterministic communication between controllers, operator stations, and I/O subsystems. Despite being a mature platform, TDC 3000 / LCN hardware remains in active service at thousands of sites worldwide, driven by the prohibitive cost and operational risk of full DCS migration projects. DriveKNMS maintains a dedicated inventory of LCN-series modules to support these long-lifecycle installations.

The Evolution of LCN Architecture

The TDC 3000 platform was introduced by Honeywell in the early 1980s as a successor to the TDC 2000 system. The original LCN used a coaxial cable bus; later revisions transitioned to a redundant coaxial topology with improved noise immunity. The K-series modules (prefixed with "K") represent the third-generation LCN hardware, replacing the earlier C-series and E-series boards with higher memory density, faster processors, and improved diagnostics. The K4LCN designation specifically identifies fourth-generation LCN node cards with expanded addressable memory. Compatibility between generations requires careful verification: K-series modules are not directly interchangeable with C-series or E-series counterparts without firmware and backplane compatibility checks. The Universal Control Network (UCN) and Plant Network (PN) layers sit above the LCN and introduce additional gateway modules (NIM, HG) that must be version-matched to the LCN node firmware. Sites running TDC 3000 R600 through R800 software releases face particular sourcing challenges as Honeywell has formally discontinued hardware support for pre-R900 configurations.

TDC 3000 / LCN Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly sourced components within the Honeywell TDC 3000 / LCN ecosystem. Each entry reflects a distinct functional role within the system architecture.

Controllers & Processor Modules

• 51403519-160 K4LCN-16: LCN node memory processor module, 16 MB configuration, fourth-generation K-series architecture.
• 51403519-200 K4LCN-20: LCN node memory processor module, 20 MB extended memory variant for high-tag-count applications.
• 51401642-100 KPMC: Process Manager Controller card; primary CPU for PM/APM process manager nodes.
• 51304485-100 KPMC-E: Enhanced Process Manager Controller; increased scan rate and expanded I/O capacity over standard KPMC.
• 51402497-200 KCPU: LCN Central Processing Unit module; core compute element for LCN node operation.
• 51401584-100 KUCN: Universal Control Network interface module; bridges LCN to UCN field device networks.

I/O Modules

• 51304754-150 HLAI: High-Level Analog Input module; 16-channel, 4–20 mA / 1–5 V input, used in PM/APM cabinets.
• 51304516-200 LLAI: Low-Level Analog Input module; thermocouple and RTD inputs, 16 channels.
• 51304441-175 HLAO: High-Level Analog Output module; 8-channel, 4–20 mA output for final control elements.
• 51304362-175 DI: Digital Input module; 32-channel 24 VDC discrete input for process status signals.
• 51304362-275 DO: Digital Output module; 32-channel 24 VDC discrete output for solenoid and relay actuation.
• 51309276-175 HLAI-CE: CE-compliant High-Level Analog Input module; CE-marked variant for European installations.

Communication & Network Adapters

• 51401195-100 NIM: Network Interface Module; UCN-to-LCN gateway, supports up to 32 UCN devices per node.
• 51401196-100 HG: Highway Gateway module; connects LCN to Plant Network (PN) for supervisory data exchange.
• 51402573-250 PLNM: Plant Loop Network Module; serial communication adapter for legacy field device integration.
• 51401584-200 KUCN-E: Enhanced UCN interface; supports higher node counts and improved diagnostics over standard KUCN.

Power Supply Modules

• 51109684-100 PS: LCN cabinet power supply module; 24 VDC regulated output, redundant-capable.
• 51195386-100 PS-CE: CE-compliant power supply variant; 24 VDC, designed for IEC-compliant cabinet configurations.
• 51401311-100 KPSU: K-series Power Supply Unit; dedicated to K-series LCN node cabinets, hot-swap capable.

Sourcing Hard-to-Find & Obsolete TDC 3000 / LCN Parts

Honeywell formally ended new production of the majority of TDC 3000 / LCN hardware. Replacement modules are no longer available through standard distribution channels. DriveKNMS operates a dedicated lifecycle extension program for this platform, maintaining physical stock of pulled, refurbished, and new-surplus K-series and C-series modules. Our sourcing network covers decommissioned plant inventories across North America, Europe, and Asia-Pacific. For sites operating under long-term service agreements or consent decree maintenance schedules, we provide documented traceability records including original manufacturer date codes, revision levels, and firmware version stamps where recoverable. Priority sourcing is available for emergency breakdown situations with same-day quotation response.

Quality Control for the TDC 3000 / LCN Range

LCN modules present specific test challenges due to their proprietary backplane bus protocol and node-address-dependent initialization sequences. DriveKNMS employs a dedicated LCN test bench replicating a functional TDC 3000 cabinet environment, including a live LCN segment with active NIM and HG nodes. Each processor module (K4LCN, KCPU, KPMC) undergoes full node initialization, memory address verification, and communication handshake testing against a reference PM node. Analog I/O modules are calibrated against NIST-traceable references with full 16-channel sweep verification. Digital I/O modules are tested for channel isolation, leakage current, and response time. All modules are inspected for electrolytic capacitor condition, battery backup integrity (where applicable), and EEPROM read/write functionality prior to shipment.

© 2026 DriveKNMS. All trademarks belong to their respective owners. Specifications are for reference only and subject to change without notice. Verify all parameters against official documentation before installation.