Honeywell LCN Modules K2LCN-8 51401551-801

Technical Dossier

Product Details And Specifications

Honeywell LCN Series Technical Notes

The Evolution of LCN Architecture

The LCN was introduced by Honeywell in the early 1980s as part of the TDC 3000 platform, replacing the earlier Highway architecture with a higher-bandwidth, more deterministic network topology. The original LCN used RG-6 coaxial cable with a dual-redundant ring configuration, providing fault tolerance at the network layer. Early nodes included the AM (Application Module), HM (History Module), and NIM (Network Interface Module), which interfaced the LCN to the Universal Control Network (UCN) and the plant-level data highway.

Through the 1990s, Honeywell introduced the K2LCN generation of modules, which offered increased processing power, expanded memory, and improved diagnostics over the original LCN node hardware. The K2LCN designation denotes second-generation LCN node cards, with the K4LCN series following as a further performance upgrade. By the 2000s, Honeywell's Experion PKS platform introduced the Server-Node architecture, which could coexist with legacy LCN nodes via the LCN-to-Experion bridge, allowing phased migration without full cutover. Today, the LCN series is in the mature-to-end-of-life phase. Honeywell has formally discontinued manufacturing for most LCN module variants. Spare parts availability through OEM channels is severely constrained, making third-party MRO suppliers the primary source for ongoing maintenance and emergency replacement.

LCN Full Catalog & Functionalities (SKU List)

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

K2LCN-8 51401551-801: K2LCN node card, 8-slot backplane interface, second-generation LCN processor module for TDC 3000 AM/HM nodes.
K2LCN-4 51401550-100: K2LCN 4-slot variant, compact node processor for space-constrained LCN enclosures.
K4LCN-8 51304362-150: K4LCN enhanced processor, 8-slot, increased RAM and faster cycle time vs K2LCN generation.
K4LCN-4 51304362-100: K4LCN 4-slot processor, drop-in upgrade path from K2LCN-4 in compatible backplanes.
NIM 51401457-100: Network Interface Module, bridges LCN coaxial bus to UCN for field controller communication.
AM 51401457-200: Application Module, executes advanced control strategies and plant-wide calculations on the LCN.
HM 51401457-300: History Module, provides continuous process data archiving and trend storage on the LCN bus.
GUS 51401457-400: Global User Station interface card, connects operator workstation to LCN for real-time process display.
PHD 51401457-500: Process History Database node card, long-term historian data storage and retrieval module.
LCN Tap 51190494-100: Passive coaxial tap unit, connects individual node enclosures to the LCN dual-redundant coax ring.
LCN Terminator 51190494-200: Bus termination resistor assembly, required at each physical end of the LCN coaxial segment.
LCNP4 51304752-100: LCN Power Supply, 4-slot enclosure power module, provides regulated DC to node backplane.
LCNP8 51304752-200: LCN Power Supply, 8-slot enclosure variant, higher current capacity for fully populated backplanes.
51401491-100: LCN Coax Cable Assembly, pre-terminated RG-6 segment for inter-enclosure LCN ring wiring.
51401491-200: LCN Coax Cable Assembly, extended-length variant for rack-to-rack or building-to-building LCN runs.
51304487-100: LCN Backplane, 8-slot passive backplane for K2LCN and K4LCN node card installation.
51304487-200: LCN Backplane, 4-slot passive backplane, compatible with K2LCN-4 and K4LCN-4 processor cards.
51401551-802: K2LCN-8 variant with extended firmware revision, functionally equivalent to 51401551-801 with updated EEPROM.
51401551-100: Early-revision K2LCN-8 board, original production run, compatible with TDC 3000 R100–R400 software releases.

Quality Control for the LCN Range

LCN modules present specific test challenges due to their dependence on the LCN coaxial bus protocol and backplane communication architecture. DriveKNMS applies a structured verification process for all LCN inventory: