Allen-Bradley 1771 PC Board Modules: SP-110996 / SP-105060 / 105066-02

Technical Dossier

Product Details And Specifications

Allen-Bradley 1771 Series: Comprehensive Module Range and Technical Overview

The Allen-Bradley 1771 I/O system, developed by Rockwell Automation, represents one of the most widely deployed programmable controller platforms in global heavy industry. Installed across petrochemical refineries, nuclear power facilities, offshore platforms, pulp and paper mills, and automotive assembly lines, the 1771 chassis-based architecture has maintained a dominant installed base since its introduction in the late 1970s. PC boards such as the SP-110996, SP-105060, and 105066-02 are internal replacement circuit boards used to restore failed 1771-series I/O modules and processor units to full operational specification without full module replacement — a critical capability for facilities operating legacy control infrastructure.

The Evolution of 1771 Architecture

The 1771 platform was introduced as part of Allen-Bradley's PLC-2 and PLC-3 controller families and later extended to support the PLC-5 processor series. The architecture is built around a passive backplane chassis (available in 4-, 8-, 12-, and 16-slot configurations) with a parallel I/O bus. Over four decades, the platform evolved through multiple generations:

• Early Generation (1977–1985): PLC-2 compatible I/O with discrete and analog modules. Limited diagnostics.
• Mid Generation (1985–1995): PLC-5 integration, expanded analog resolution, introduction of specialty modules (HART, encoder, servo).
• Late Generation (1995–2010): ControlNet and DH+ communication adapters added. Enhanced fault diagnostics. Module-level replacement parts (PC boards) became standard maintenance items.
• End-of-Life / Sustaining Phase (2010–present): Rockwell Automation has formally discontinued new production of most 1771 modules. Facilities are advised to maintain spare parts inventory. PC board-level repair is the primary cost-effective maintenance strategy.

Compatibility note: 1771 I/O modules are not directly interchangeable with the newer 1746 (SLC 500) or 1756 (ControlLogix) platforms without chassis and wiring modifications.

1771 Series Full Catalog & Functionalities (SKU List)

The following represents a cross-section of the Allen-Bradley 1771 module catalog, organized by functional category. All models listed are genuine Allen-Bradley / Rockwell Automation part numbers.

Discrete Input Modules

• 1771-IA: 120V AC 16-point discrete input module
• 1771-IB: 24V DC 16-point discrete input, source type
• 1771-IC: 220V AC 8-point discrete input module
• 1771-ID: 24V DC 32-point discrete input module
• 1771-IG: TTL-compatible 32-point discrete input module

Discrete Output Modules

• 1771-OA: 120V AC 16-point discrete output, triac type
• 1771-OB: 24V DC 16-point discrete output, transistor sink
• 1771-OD: 24V DC 32-point discrete output module
• 1771-OW: Relay contact 16-point discrete output module

Analog I/O Modules

• 1771-IFE: 8-channel analog input, 4–20 mA / 0–10V configurable
• 1771-OFE1: 4-channel analog output, 4–20 mA
• 1771-OFE2: 4-channel analog output, 0–10V DC

Specialty & Communication Modules

• 1771-ASB: Remote I/O adapter for 1771 chassis, DH+ compatible
• 1771-DCM: Direct communication module for DH+ network integration
• 1771-IXHR: High-resolution thermocouple/RTD input module

PC Board Replacement Parts (Current Listing)

• SP-110996: Replacement PC board for 1771-series I/O module internal logic circuit
• SP-105060: Internal circuit board assembly for 1771 analog or discrete module repair
• 105066-02: Revision 02 PC board sub-assembly for 1771 module restoration

Sourcing Hard-to-Find & Obsolete 1771 Series Parts

With Rockwell Automation having discontinued active production of the majority of 1771-series modules, the global supply of new-in-box units is finite and diminishing. DriveKNMS maintains a dedicated inventory of 1771 PC boards, module assemblies, and sub-components sourced through authorized surplus channels and controlled decommissioning programs.

Our sourcing capabilities for the 1771 platform include:

• PC board-level replacements (SP-series and numeric part numbers) for failed modules
• Tested-good pulled units from decommissioned facilities
• New-old-stock (NOS) modules with original factory packaging where available
• Cross-reference support for obsolete part numbers to current equivalent boards

DriveKNMS provides lifecycle extension support for facilities that cannot migrate to ControlLogix or other modern platforms due to process criticality, budget constraints, or regulatory requirements.

Quality Control for the 1771 PC Board Range

All 1771 PC boards processed by DriveKNMS undergo a structured inspection and functional verification protocol prior to dispatch:

• Visual Inspection: Board-level examination for burnt components, cracked traces, corrosion, and capacitor failure.
• Component-Level Testing: Verification of critical ICs, power regulation circuits, and bus interface logic using bench test equipment.
• Backplane Bus Simulation: Where applicable, boards are tested under simulated 1771 backplane bus conditions to verify I/O addressing and data transfer integrity.
• Functional Burn-In: Extended power-on testing to identify latent failures before shipment.
• Documentation: Each unit ships with a test record and condition report.