Allen-Bradley MicroLogix 1400 Modules: 1766-L32BXBA

Technical Dossier

Product Details And Specifications

Allen-Bradley MicroLogix 1400 Series Technical Notes

The Allen-Bradley MicroLogix 1400 series (catalog prefix: 1766) is a compact, fixed-I/O programmable logic controller platform developed by Rockwell Automation. It occupies a defined position in the Rockwell small controller hierarchy, sitting above the MicroLogix 1100 and below the MicroLogix 1500. The platform is deployed across global heavy industry sectors including petrochemical processing, refinery automation, water treatment infrastructure, pharmaceutical batch control, and discrete manufacturing. Its embedded EtherNet/IP port (on select models), onboard LCD operator interface, and support for up to 256 I/O points via expansion have made it a standard-specification controller in facilities requiring compact footprint with mid-range I/O density. Installed base concentration is highest in North American and Asia-Pacific process industries, with significant legacy deployments in European chemical and automotive plants.

The Evolution of MicroLogix 1400 Architecture

The MicroLogix 1400 was introduced as a successor to the MicroLogix 1200, addressing demand for integrated Ethernet connectivity and expanded analog I/O without migrating to the larger SLC 500 or CompactLogix platforms. Early production units (pre-2010) shipped without the embedded EtherNet/IP port; this was added in subsequent hardware revisions, creating two distinct hardware generations that share the same catalog number structure but differ in firmware capability ceilings.

The controller uses a fixed backplane architecture — there is no modular rack. Expansion is achieved via the 1762 MicroLogix Expansion I/O modules, which connect via a dedicated expansion bus on the right side of the base unit. Up to 7 expansion modules are supported, enabling configurations from 32 to 256 discrete I/O points. Communication options include RS-232 (Channel 0), RS-232/RS-485 (Channel 1), and EtherNet/IP (on -E suffix models). Programming is performed exclusively via RSLogix 500 / Studio 5000 Logix Designer (legacy compatibility mode) using ladder diagram logic.

As of 2024, the MicroLogix 1400 series has entered the End of Life / Mature phase of the Rockwell Automation product lifecycle. Rockwell's recommended migration path is to the Micro820 or Micro850 (Connected Components Workbench platform) for new designs. However, the installed base remains extensive, and replacement units, spare I/O modules, and communication adapters continue to be required for maintenance and lifecycle extension programs at operating facilities.

MicroLogix 1400 Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified production catalog for the MicroLogix 1400 (1766) base units and associated 1762 expansion I/O. All models listed are confirmed Allen-Bradley catalog numbers.

Base Controller Units (1766 Series)

• 1766-L32BXBA: 32-pt base unit, 24VDC in / relay & transistor out, RS-232/RS-485, no Ethernet
• 1766-L32AWAA: 32-pt base unit, 120VAC input / relay output, RS-232 Ch0+Ch1, no Ethernet
• 1766-L32BWAA: 32-pt base unit, 24VDC input / relay output, RS-232 Ch0+Ch1, no Ethernet
• 1766-L32AWWA: 32-pt base unit, 120VAC input / relay output, with EtherNet/IP port
• 1766-L32BWWA: 32-pt base unit, 24VDC input / relay output, with EtherNet/IP port
• 1766-L32BXBA: 32-pt base unit, 24VDC in / transistor (sink) out, RS-485, no Ethernet
• 1766-L32BXBC: 32-pt base unit, 24VDC in / transistor (source) out, RS-485, no Ethernet
• 1766-L32BWBC: 32-pt base unit, 24VDC in / relay out, EtherNet/IP, sourcing transistor variant
• 1766-MM1: 1MB Flash memory module for MicroLogix 1400 program backup and transfer

1762 Expansion I/O Modules (Digital)

• 1762-IA8: 8-pt 120VAC discrete input expansion module
• 1762-IQ8: 8-pt 24VDC discrete input expansion module (sinking)
• 1762-IQ16: 16-pt 24VDC discrete input expansion module
• 1762-OA8: 8-pt 120/240VAC discrete output expansion module
• 1762-OB8: 8-pt 24VDC discrete output expansion module (sourcing)
• 1762-OB16: 16-pt 24VDC discrete output expansion module (sourcing)
• 1762-OW8: 8-pt relay output expansion module, 10–265VAC/VDC
• 1762-OW16: 16-pt relay output expansion module

1762 Expansion I/O Modules (Analog)

• 1762-IF4: 4-ch analog input module, 4–20mA / 0–10V selectable
• 1762-OF4: 4-ch analog output module, 4–20mA / 0–10V selectable
• 1762-IF2OF2: 2-ch analog input + 2-ch analog output combination module
• 1762-IT4: 4-ch thermocouple / mV input module, types J/K/T/E/R/S/B/N
• 1762-IR4: 4-ch RTD input module, PT100/PT1000/Ni/Cu

Communication & Specialty Modules

• 1762-NC01: RS-232/RS-485 serial communication cable for Channel 1 configuration
• 1762-RTC: Real-time clock module for time-stamped data logging applications

Sourcing Hard-to-Find & Obsolete MicroLogix 1400 Parts

All units are inspected against original Rockwell Automation hardware revision documentation. Firmware version compatibility is verified prior to dispatch. DriveKNMS supports customers requiring exact hardware revision matches for validated production environments where firmware upgrades are not permissible under site change-control procedures.

Quality Control for the MicroLogix 1400 Range

MicroLogix 1400 base units undergo a structured functional test protocol prior to shipment from DriveKNMS. The test sequence covers: power-on self-test (POST) verification, RS-232/RS-485 channel loopback communication test, EtherNet/IP ping and CIP connection establishment (for -W suffix models), discrete I/O point-by-point actuation and readback, analog I/O calibration verification against factory tolerance bands (±0.1% full scale), and LCD display and keypad functional check.