Configured for discrete 120 VAC signal acquisition in ControlLogix chassis architectures, the Allen-Bradley 1756-IA16 (1756-IA16 Digital AC Input Module) provides direct physical/electrical execution.

Hardware Variant Structure

• 1756-IA16: Standard 16-point 120 VAC discrete AC input module arranged in 2 isolated groups of 8 channels each.
• 1756-IA16/A: Series A hardware assembly revision designed for standard ControlLogix 1756 backplane mounting slots.

Electrical and Physical Specifications

Deterministic System Bus Integration

The discrete input module transfers channel data directly across the 1756 backplane, maintaining high backplane bus communication velocity and optimal I/O density scaling. Integrated firmware flash compatibility supports real-time status updating across EtherNet/IP deterministic networks without introducing scan latency into ControlLogix PAC tasks.

Order Package Contents

• 1 x Allen-Bradley 1756-IA16 digital input module
• Anti-static protective enclosure bag
• Slot keying tab kit for 1756 backplane installation

Field Installation Guidelines

• Remove system power from the ControlLogix rack prior to inserting or removing the I/O module.
• Align board card edges with the top and bottom chassis guides and push firmly until slot levers click shut.
• Connect 120 VAC field inputs to the removable terminal block (RTB) according to group isolation rules.
• Terminate field wiring shield conductors directly to the cabinet earth bus using low-impedance grounding clamps.
• Route high-voltage AC input lines away from low-voltage DC bus lines and network communication cables.

Frequently Asked Questions

• What backplane current does this module draw at 5.1 VDC?

  The board draws 100 mA at 5.1 VDC directly from the backplane, resulting in a total backplane power draw of 0.58 W.

• What voltage range qualifies as a valid ON-state signal?

  Input channels evaluate incoming signals as active ON states across an operating range of 74 VAC to 132 VAC.

• What hardware filter options are available for signal debounce?

  Software selectable hardware input delay times can be programmed for either 9 ms or 18 ms filtration profiles.

• How are the 16 input channels grouped on the field terminal side?

  The 16 channels are split into two electrically isolated groups containing 8 points per group.

• Can the card be safely removed while the rack is powered?

  The module features Removal and Insertion Under Power (RIUP) support, but field-side wiring must be de-energized.

• What is the minimum operating current needed for signal detection at 74 VAC?

  Each channel requires a minimum operating current of 5 mA at 74 VAC to guarantee active state recognition.

• What cyclic update times can be configured for data transfer?

  The module supports cyclic update intervals configurable from 200 us up to 750 ms depending on task requirements.

• How is firmware flash compatibility ensured during module replacement?

  Verify that the replacement module major and minor revision numbers match the module profile in Studio 5000.