The Allen-Bradley 1756-IM16I, also cataloged as the 1756IM16I Isolated Digital Input Module, operates as a dedicated hardware component for high-voltage AC discrete signal acquisition within ControlLogix system chassis. It converts 240 VAC field signals into backplane-compatible logic levels across 16 point-to-point isolated channels.

Channel Nomenclature & Structural Matrix

• 1756: Chassis-based ControlLogix programmable automation controller I/O system.
• IM: High-voltage AC digital input module rating designed for 240 VAC nominal level execution.
• 16: 16 discrete input points with independent power routing flexibility.
• I: Individually isolated channel topology for distinct phase or circuit isolation.

Technical Parameters & Electrical Ratings

Backplane Connectivity & Deterministic Communications

The module leverages backplane bus communication velocity to stream discrete status bits directly to the primary controller. Fully compatible with EtherNet/IP deterministic networks, it transmits cyclic I/O data and diagnostic flags without degrading system throughput. Enhanced I/O density scaling allows 16 channel-to-channel isolated AC inputs within a standard single-slot chassis footprint, supported by firmware flash compatibility for direct integration into Studio 5000 Logix Designer tasks.

Order Fulfillment Package Contents

• 1 x Allen-Bradley 1756-IM16I module housed in anti-static protective wrap
• 1 x Installation insert sheet detailing field wiring layouts

Enclosure Mounting & Wiring Protocol

• Align module guide rails carefully with the chassis slot before pushing firmly to seat backplane connectors.
• Maintain minimum 50 mm clearance above and below the chassis assembly to preserve passive airflow.
• Keep 240 VAC high-voltage AC field signal cabling physically separated from low-voltage DC communication bus lines.
• Secure field wiring to compatible Removable Terminal Blocks (RTB) using appropriate wire gauge and torque limits.

Technical Hardware Reference FAQ

• What is the input delay time for signal state transitions?

  The module provides hardware filtering delay settings selectable at 9 ms or 18 ms to accommodate field contact debouncing.

• Can different AC phases be wired across separate channels?

  Yes, because all 16 channels feature individual channel-to-channel isolation, distinct AC phases or power sources can be wired.

• Is Removal and Insertion Under Power (RIUP) supported for this card?

  Yes, the module supports RIUP under system power, provided field wiring circuits are safely de-energized prior to disconnect.

• What threshold defines the off-state current limit?

  An input channel remains in the off-state as long as field leakage current stays at or below the maximum limit of 2.5 mA.

• Which Removable Terminal Block (RTB) options fit this module?

  It pairs with standard 36-pin ControlLogix terminal blocks such as the 1756-TBCH or 1756-TBS6H removable wiring assemblies.

• Does the module require external control logic configuration?

  Yes, parameters such as input filter times and point-level diagnostic reporting are configured via the Studio 5000 I/O tree.

• How does individual channel isolation protect system electronics?

  Galvanic barriers between input channels prevent voltage spikes or shorts on one field line from affecting adjacent channels.

• What voltage range constitutes an active on-state signal?

  The inputs recognize an active on-state signal when the field voltage is sustained within the range of 159 to 265 VAC.