Product Overview

The Allen-Bradley 1756-IB16 is a high-density discrete input module designed for the ControlLogix® platform. It provides 16 sinking DC input channels, organized into two isolated groups of eight points each. This module acts as the primary interface between field-side digital devices—such as limit switches, push buttons, and electronic sensors—and the Logix5000™ controller.

Engineered for versatility, the 1756-IB16 supports a wide operating voltage range, making it compatible with both 12V and 24V DC control circuits. It is a fundamental component for discrete automation, offering high-speed signal registration and robust electrical protection for the PLC backplane.

Technical Specifications

• Manufacturer: Allen-Bradley / Rockwell Automation

• Model Number: 1756-IB16

• Input Type: Digital DC Sinking Input

• Number of Inputs: 16 (2 groups of 8)

• Operating Voltage Range: 10–31.2V DC

• Nominal Input Voltage: 24V DC

• Backplane Current (5.1V): 100 mA

• Backplane Current (24V): 2 mA

• Power Dissipation (Max): 5.1 Watts

• Off-State Voltage (Max): 5V DC

• On-State Current (Min): 2 mA @ 10V DC

• Dimensions: 3.5 x 13.0 x 14.5 cm

• Weight: 0.9 kg

Performance and Advanced Features

The 1756-IB16 is distinguished by its ability to handle high-speed industrial processes through several programmable logic features:

• Change of State (COS) Detection: The module can be configured to notify the controller immediately when an input transitions from On to Off or vice versa. This event-driven communication reduces the need for constant polling and ensures faster system response times.

• Configurable Digital Filtering: To eliminate "chatter" from mechanical contacts or electrical noise, users can define filter times (0 to 18ms) for both Off-to-On and On-to-Off transitions.

• Isolation and Protection: Featuring 250V continuous isolation between groups and from the backplane, the module prevents ground loops and protects sensitive logic circuitry from field-side surges.

• Removable Terminal Block (RTB) Compatibility: The 1756-IB16 interfaces with the 1756-TBNH or 1756-TBSH terminal blocks, allowing for pre-wiring and rapid module replacement without disconnecting field leads.

Application Environments

Due to its reliability and modular nature, the 1756-IB16 is a staple in diverse sectors including:

• Discrete Manufacturing: Assembly lines where rapid sensor feedback is critical.

• Process Automation: Monitoring status valves and motor starter auxiliaries in PlantPaX® systems.

• Material Handling: Detecting pallet positions and conveyor gate statuses.