The Allen-Bradley 1756-IN16, also cataloged as the 1756-IN16 Digital AC Input Module, operates as a dedicated hardware component for acquiring 24 VAC field signals within ControlLogix controller platforms.

Model Identification & Product Scope

The 1756-IN16 is a ControlLogix Digital AC Input Module designed for monitoring discrete AC voltage signals from field devices. The module provides 16 input channels with programmable input delay settings for integration into ControlLogix I/O architectures.

Hardware Specifications

EtherNet/IP and ControlLogix Bus Integration

The 1756-IN16 module operates as a ControlLogix chassis-based I/O component and exchanges input status data through the controller backplane communication structure. The module architecture supports deterministic I/O data handling required for PLC-based automation systems.

ControlLogix I/O density scaling allows multiple input modules to be combined within a chassis configuration while maintaining organized channel-level signal monitoring. Firmware flash compatibility and module revision management must be verified before integration into existing controller systems.

Ordering Information

• 1 x Allen-Bradley 1756-IN16 ControlLogix Digital AC Input Module
• 1 x Factory-installed terminal block compatibility interface
• 1 x Product identification label with catalog number
• Installation documentation provided according to supplier configuration

Field Installation Guidelines

Chassis Mounting

• Install the module only in a compatible ControlLogix chassis slot.
• Confirm chassis power removal before inserting or removing the module.
• Verify module keying position to prevent incorrect hardware installation.

Field Wiring

• Connect AC field signals according to the terminal block wiring diagram.
• Maintain separation between AC input wiring and high-current power conductors.
• Use appropriate shielding and grounding practices where electrical noise is present.
• Confirm input voltage levels before applying field power.

Maintenance Checks

• Inspect terminal connections periodically for mechanical loosening.
• Verify input channel status through the ControlLogix controller diagnostics.
• Check environmental conditions when operating in high-temperature or vibration areas.

Frequently Asked Questions

• Does the 1756-IN16 support DC input signals?

  No. The 1756-IN16 is designed for AC discrete input signals and operates within its specified AC voltage range.

• How many field input channels are available on this module?

  The module provides 16 independent digital AC input channels for discrete signal monitoring.

• Can the input delay be adjusted?

  Yes. The input delay setting is programmable with selectable delay values of 9 ms or 18 ms.

• Is the module installed directly on the ControlLogix backplane?

  Yes. The module is installed in a ControlLogix chassis and communicates through the controller backplane.

• What is the operating voltage range of the input channels?

  The module accepts AC input signals from 10 VAC to 30 VAC according to the specified operating range.

• Does the module require external power wiring?

  The module receives operating power through the ControlLogix chassis backplane; field devices provide the input signals.

• Can the module be replaced while the chassis is energized?

  Hot-swap capability depends on the installed ControlLogix system configuration and maintenance procedures.

• What wiring practice is recommended for AC input connections?

  Field wiring should follow industrial control standards with proper separation, grounding, and noise reduction methods.