Honeywell TDC 3000 LCN Modules: 51308112-008 LCN Coax Cable Set 8M REV D & Full Series

Technical Dossier

Product Details And Specifications

Honeywell TDC 3000 LCN Series Technical Notes

The Honeywell TDC 3000 (Total Distributed Control) platform is one of the most widely deployed Distributed Control Systems in global heavy industry. Installed across petrochemical complexes, nuclear power stations, crude oil refineries, pulp and paper mills, and large-scale chemical processing facilities, the TDC 3000 architecture has maintained operational continuity at thousands of sites since its commercial introduction in the early 1980s. Its Local Control Network (LCN) backbone — a deterministic, token-passing coaxial bus — remains the primary data highway connecting operator stations, history modules, application modules, and process controllers. The 51308112-008 LCN Coax Cable Set 8M REV D is a certified physical-layer component of this network, providing the standardized 8-meter coaxial interconnect between LCN nodes with revision D engineering changes applied for improved shielding and connector retention.

The Evolution of TDC 3000 LCN Architecture

The TDC 3000 platform was introduced by Honeywell in 1983 as the successor to the TDC 2000, transitioning from a Highway Data Link (HDL) architecture to the higher-bandwidth Local Control Network (LCN). The LCN operates at 5 Mbps over RG-6 coaxial cable in a dual-redundant configuration, supporting up to 64 nodes per segment. Early LCN implementations used single-redundant cabling; REV D and later revisions of cable sets such as the 51308112-008 introduced dual-shield construction and improved BNC-to-N-type adapters to reduce signal reflection at high node counts.

Through the 1990s, Honeywell introduced the Universal Control Network (UCN) as a field-level bus beneath the LCN, and later the Fault Tolerant Ethernet (FTE) as a supervisory overlay. However, the LCN physical layer — including coax cable sets, LCN Interface Modules (LNI), and Network Interface Modules (NIM) — remained unchanged, ensuring backward compatibility across three decades of platform evolution. As of 2026, the TDC 3000 LCN series is in its end-of-life / sustained support phase. Honeywell ceased new manufacturing of most LCN hardware modules circa 2010–2015, making certified aftermarket and refurbished inventory the primary sourcing channel for ongoing plant maintenance.

TDC 3000 LCN Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked components within the Honeywell TDC 3000 LCN ecosystem. Each entry reflects a distinct hardware function within the LCN architecture.

Connectivity & Cable Infrastructure

• 51308112-008: LCN Coax Cable Set 8M REV D — 8-meter dual-shield RG-6 coax interconnect for LCN node-to-node wiring.
• 51308112-175: LCN Coax Cable Set 175M — long-run coaxial segment cable for extended LCN bus spans.
• 51308112-025: LCN Coax Cable Set 25M — mid-length coax cable for inter-cabinet LCN connections.
• 51304485-100: LCN Tap Unit — passive directional coupler for connecting node drop cables to the LCN trunk.
• 51304485-200: LCN Terminator Assembly — 75-ohm impedance terminator for LCN bus end-of-line termination.

Network Interface Modules (NIM / LNI)

• 51401288-100: LCN Interface Module (LNI) — primary LCN node interface card for AM/HM/APP modules.
• 51401288-200: LCN Interface Module REV B — updated LNI with enhanced error-correction logic.
• 51304516-100: Network Interface Module (NIM) — UCN-to-LCN gateway module for field controller integration.
• 51304516-150: NIM REV C — revised NIM with expanded UCN node capacity (up to 32 UCN nodes).

Application & History Modules

• 51401195-100: Application Module (AM) — LCN-resident process application execution node, 4 MB RAM baseline.
• 51401195-200: Application Module REV B — expanded to 8 MB RAM with additional co-processor support.
• 51401196-100: History Module (HM) — LCN-resident process data historian, 20 MB disk baseline.
• 51401196-200: History Module REV B — upgraded to 40 MB storage with faster data retrieval bus.

Power Supply Modules

• 51109814-175: LCN Power Supply 24VDC — regulated 24 VDC rail supply for LCN node backplane.
• 51109814-225: LCN Power Supply 24VDC REV B — revised supply with improved thermal management and over-voltage protection.
• 51190436-175: Redundant Power Supply Module — hot-swap redundant PSU for continuous LCN node availability.

Operator & Universal Stations

• 51401094-100: Universal Station (US) Processor Board — main CPU card for TDC 3000 operator workstation.
• 51401094-200: Universal Station Processor REV B — upgraded clock speed and expanded video buffer.
• 51304487-100: Global User Station (GUS) Interface Card — Ethernet-to-LCN bridge for GUS operator console integration.

Quality Control for the TDC 3000 LCN Range

LCN hardware presents specific test challenges due to the deterministic, token-passing nature of the bus protocol and the sensitivity of coaxial physical-layer components to impedance discontinuities. DriveKNMS applies the following test procedures to all TDC 3000 LCN inventory: