Emerson KL Series Modules: KL3031X1-BA1 12P4630X112

Technical Dossier

Product Details And Specifications

Emerson KL Series: Comprehensive Module Range and Technical Overview

The Emerson KL Series represents a family of compact, bus-terminal I/O modules originally developed under the Beckhoff KL-bus architecture and widely adopted within Emerson DeltaV and third-party distributed control system (DCS) environments. These modules are deployed across continuous-process industries including petroleum refining, chemical manufacturing, pulp and paper, and power generation. Their compact DIN-rail form factor, deterministic bus communication, and broad signal-type coverage made them a standard selection for I/O expansion in facilities built between the late 1990s and mid-2010s. Many of these installations remain operational today, and the KL Series has entered a mature-to-declining lifecycle phase, with several models no longer in active production. Facilities running KL-based I/O infrastructure face a defined maintenance horizon: sourcing replacement modules from the secondary market is now the primary strategy for sustaining uptime without committing to full system re-architecture.

The Evolution of KL Series Architecture

The KL bus terminal system was introduced by Beckhoff Automation in the mid-1990s as a modular, field-level I/O solution using a proprietary K-bus backplane protocol. Modules communicate via a serial, synchronous K-bus that passes data and power through direct terminal-to-terminal contact, eliminating the need for individual wiring between modules. Emerson integrated KL-compatible I/O into DeltaV system architectures as remote I/O nodes, particularly in applications requiring dense analog signal acquisition in confined panel spaces.

Early KL modules (pre-2000) used through-hole PCB construction and were rated for standard industrial temperature ranges. Mid-generation modules introduced surface-mount components, improved EMC shielding, and extended temperature variants (denoted by the X suffix in part numbers, e.g., KL3031X1). Later revisions added firmware-configurable parameters accessible via the KS2000 configuration software or TwinCAT engineering environment. As of 2026, Beckhoff has transitioned its primary I/O platform to the EL Series (EtherCAT Terminals), and KL Series production has been progressively wound down. Compatibility between KL and EL modules requires a KL/EL bridge coupler (e.g., EL6695 or KL9100) and is not transparent at the application layer — a direct swap is not possible without engineering intervention.

KL Series Full Catalog & Functionalities (SKU List)

The following models represent confirmed KL Series part numbers across analog input, analog output, digital I/O, communication, and power supply categories. Each entry reflects a distinct hardware function within the KL bus terminal ecosystem.

Analog Input Modules (AI)

• KL3001: 1-channel analog input, 0–10 V, 12-bit resolution, single-ended
• KL3002: 2-channel analog input, 0–10 V, 12-bit resolution
• KL3011: 1-channel analog input, 0–20 mA current, 12-bit
• KL3012: 2-channel analog input, 0–20 mA current, 12-bit
• KL3021: 1-channel analog input, 4–20 mA, with HART communication support
• KL3022: 2-channel analog input, 4–20 mA, 12-bit resolution
• KL3031: 1-channel RTD input, PT100/PT1000/Ni100, 16-bit resolution — standard temperature variant
• KL3031X1-BA1 12P4630X112: 1-channel RTD input module, extended temperature variant, PT100/PT1000/Ni100/Ni1000 compatible, 16-bit resolution, DeltaV-qualified configuration — this listing
• KL3042: 2-channel analog input, ±10 V, differential, 12-bit
• KL3052: 2-channel analog input, ±20 mA, differential, 12-bit
• KL3062: 2-channel analog input, 0–10 V, 16-bit high-resolution
• KL3102: 2-channel analog input, ±10 V, 16-bit, differential measurement
• KL3132: 1-channel thermocouple input, type J/K/L/E/N/B/R/S, 16-bit
• KL3162: 2-channel analog input, 0–20 mA, 16-bit high-resolution
• KL3172: 2-channel analog input, 4–20 mA, 16-bit, with wire-break detection

Analog Output Modules (AO)

• KL4001: 1-channel analog output, 0–10 V, 12-bit
• KL4002: 2-channel analog output, 0–10 V, 12-bit
• KL4011: 1-channel analog output, 0–20 mA, 12-bit
• KL4021: 1-channel analog output, 4–20 mA, 12-bit

Digital Input Modules (DI)

• KL1002: 2-channel digital input, 24 V DC, positive switching
• KL1104: 4-channel digital input, 24 V DC, filter configurable
• KL1408: 8-channel digital input, 24 V DC, standard

Digital Output Modules (DO)

• KL2012: 2-channel digital output, 24 V DC, 0.5 A per channel
• KL2408: 8-channel digital output, 24 V DC, 0.5 A

Communication & System Modules

• KL6001: 1-channel serial interface, RS232, configurable baud rate
• KL6021: 1-channel serial interface, RS485/RS422
• KL9010: Bus end terminal — required at the end of every KL bus segment
• KL9100: Power feed terminal, 24 V DC bus supply

Sourcing Hard-to-Find & Obsolete KL Series Parts

The KL3031X1-BA1 12P4630X112 and related extended-temperature KL variants are no longer available through standard distribution channels. Emerson and Beckhoff have both confirmed end-of-life status for the majority of KL Series analog input modules. For plant operators running DeltaV systems with KL I/O nodes, the options are: (1) migrate to EL Series with engineering rework, (2) migrate to DeltaV CHARMs I/O with significant capital expenditure, or (3) maintain the existing KL infrastructure using verified secondary-market stock.

DriveKNMS maintains a dedicated inventory of KL Series modules sourced from decommissioned systems, factory overstock, and authorized resellers. All units are individually catalogued by part number, hardware revision, and firmware version prior to listing. For facilities managing 10 or more KL nodes, we recommend establishing a standing spare inventory — the cost of a single unplanned production stoppage in a refinery or chemical plant routinely exceeds the cost of maintaining a 12-month spare buffer by a factor of 10 to 50.

Quality Control for the KL Series Range

KL Series modules present specific failure modes that require targeted inspection protocols. DriveKNMS applies the following procedures to all KL units prior to dispatch:

• K-bus contact inspection: The gold-plated K-bus contacts on the left and right faces of each terminal are inspected under magnification for oxidation, mechanical deformation, and contamination. Degraded contacts are the primary cause of intermittent bus communication faults in aged KL installations.
• Electrolytic capacitor assessment: Analog input modules including the KL3031 family use electrolytic capacitors in their signal conditioning circuits. Units manufactured before 2008 are subject to elevated ESR measurement to identify capacitor aging before it causes drift or measurement error.
• Firmware version verification: KL modules store firmware in internal flash. Version is read via KS2000 or TwinCAT and recorded. Mismatched firmware versions within a bus segment can cause data frame errors.
• Functional signal test: Each analog input module is connected to a calibrated signal source and output values are verified against the module's published accuracy specification.
• Isolation resistance test: Channel-to-bus and channel-to-ground isolation is verified to confirm no internal breakdown has occurred due to overvoltage events in prior service.

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