1756-IG16 Allen-Bradley ControlLogix 16-Point TTL Input Module

Product Overview

The 1756-IG16 is a 16-point Digital DC Input Module from Allen-Bradley’s premier ControlLogix automation platform. Engineered for precision low-voltage sensing, this high-reliability module interfaces directly with 5V DC TTL (Transistor-Transistor Logic) source devices. Built into a compact card housing with a physical net weight of 0.32 kg, it slots securely into any standard ControlLogix chassis to handle fast-switching, low-power instrumentation and solid-state circuitry across demanding industrial architectures.

Key Advantages

• TTL Voltage Compatibility: Specifically optimized to handle narrow 4.5 to 5.5 Volt DC operating windows, allowing direct integration with microelectronics and TTL logic boards without interposing components.
• Configurable Signal Filtering: Combines an ultra-fast hardware input delay time of 0.25 milliseconds with user-selected digital filter periods to effectively eliminate field contact bounce and electrical line noise.
• High Power-to-Weight Efficiency: Delivers high-density 16-point signal isolation inside an exceptionally light 0.32 kg form factor, maintaining low structural load over modular multi-slot chassis backplanes.
• Rugged Industrial Protection: Features an IEC IP20 touch-safe housing rating alongside a broad operating temperature tolerance spanning from -20 to 60 °C (-4 to 140 °F).

Technical Specifications

Quick Installation Tips

• Chassis Safety Insertion: Always disconnect the main power grid from the control rack before seating or extracting the module to avoid high-voltage transients on the backplane tracks.
• TTL Wiring Distance: Keep 5V DC TTL field wires as short as possible and route them away from high-voltage AC motor lines to prevent electromagnetic induction from causing false logic state changes.
• RTB Terminal Mounting: Fasten your field circuits via the compatible screw-type Removable Terminal Block. Ensure the 0.32 kg module clicks firmly into the chassis guide rails for proper backplane bus seating.

Technical FAQs

Q1: What exactly does a "9 per common" layout mean for this 16-point card?

A1: The 16 input channels are internally split across two isolated reference groups. This wiring method uses shared common return paths to reduce the number of field terminal connections while keeping separate groups electronically isolated.

Q2: Can this module process standard 24V DC industrial proximity sensor inputs?

A2: No. The 1756-IG16 is engineered strictly for 5V TTL logic levels (4.5 to 5.5V DC). Applying 24V DC to these inputs will instantly over-stress the circuits and permanently damage the card's internal optocouplers.

Q3: How does the maximum off-state leakage current affect my field devices?

A3: The module has a maximum off-state input current limit of 4.1 mA. Connected electronic sensors must drop below this current threshold when turned off to guarantee the PLC reliably switches to a low/off logic state.