Honeywell MLF Series Modules - MLF-AD08A

Technical Dossier

Product Details And Specifications

Honeywell MLF Series Technical Notes

The Honeywell MLF Series represents a structured family of I/O and control modules deployed within Honeywell's distributed control system (DCS) infrastructure. These modules have established a significant installed base across global heavy industries including petrochemical refineries, nuclear power generation facilities, offshore platforms, and large-scale chemical processing plants. The MLF architecture is designed for high-density signal termination and deterministic scan-cycle performance, making it a standard reference in long-lifecycle plant automation environments where replacement continuity is operationally critical.

The Evolution of MLF Architecture

The MLF Series was introduced as part of Honeywell's modular field I/O strategy, designed to interface with the Experion PKS and legacy TDC 3000 / PlantScape control platforms. Early MLF modules used parallel backplane communication with fixed-address slot assignment, requiring manual DIP-switch configuration for node identification. Subsequent hardware revisions introduced auto-addressing via the FTA (Field Termination Assembly) bus, reducing commissioning time and eliminating address conflicts in multi-drop configurations.

MLF Full Catalog & Functionalities (SKU List)

Analog Input Modules

• MLF-AD08A: 8-channel analog input, 4–20 mA / 1–5 V, HART-capable, 16-bit resolution
• MLF-AD16A: 16-channel analog input, high-density signal acquisition, 4–20 mA
• MLF-AD08B: 8-channel analog input with enhanced EMI filtering for noisy field environments
• MLF-TC08A: 8-channel thermocouple input, supports J/K/T/E/R/S/B types, CJC onboard
• MLF-RTD08A: 8-channel RTD input, 2/3/4-wire PT100/PT1000 compatible

Analog Output Modules

• MLF-DA08A: 8-channel analog output, 4–20 mA, loop-powered, HART pass-through
• MLF-DA04A: 4-channel analog output, high-current drive, suitable for valve positioner loops

Digital Input Modules

• MLF-DD16A: 16-channel digital input, 24 VDC, dry contact / wet contact selectable
• MLF-DD32A: 32-channel digital input, high-density, 24 VDC, group isolation
• MLF-DD16B: 16-channel digital input, 120 VAC field voltage compatible
• MLF-DD08A: 8-channel digital input, individually isolated, for critical interlock circuits

Digital Output Modules

• MLF-DO16A: 16-channel digital output, 24 VDC, 0.5 A per channel, short-circuit protected
• MLF-DO08A: 8-channel digital output, relay-type, SPDT, 2 A / 250 VAC rated
• MLF-DO32A: 32-channel digital output, transistor sink type, high-density panel wiring

Communication & Specialty Modules

• MLF-CM01A: FOUNDATION Fieldbus H1 communication module, 2-segment, 32-device capacity
• MLF-PS24A: 24 VDC redundant power supply module for MLF backplane, 10 A rated
• MLF-BK08A: 8-slot backplane carrier, passive bus, supports hot-swap module replacement

Sourcing Hard-to-Find & Obsolete MLF Series Parts

The MLF Series has entered end-of-active-manufacturing status. Honeywell's standard commercial supply chain no longer fulfills new-build orders for most MLF part numbers. For plant operators running Experion PKS or TDC 3000 systems with MLF I/O infrastructure, unplanned module failure creates a critical sourcing gap that cannot be resolved through standard procurement channels.