1756-IN16 | AB Allen-Bradley | ControlLogix Digital AC Input Module

Product Summary

The Allen-Bradley 1756-IN16 is a 16-Point 24V AC Digital Input Module for the ControlLogix platform. It features 16 inputs organized in 2 groups of 8, with 250V continuous isolation between input groups and the backplane. The module accepts 10–30V AC signals at 47–63 Hz, making it suitable for interfacing with standard AC field devices such as limit switches, proximity sensors, and pushbuttons in industrial automation applications.

Core Specifications

• Model Number: 1756-IN16
• Type: 16-Point AC Digital Input Module
• Number of Inputs: 16 (8 points per group, 2 groups)
• Voltage Category: 24V AC
• Operating Voltage Range: 10–30V AC, 47–63 Hz
• Nominal Input Voltage: 24V AC, 50/60 Hz
• Input Delay Time (Off to On): Hardware delay: 10 ms max + filter time; User-selectable filter: 0, 1, or 2 ms
• Input Delay Time (On to Off): Hardware delay: 10 ms max + filter time; User-selectable filter: 9 or 18 ms
• Current Draw @ 5.1V: 135 mA
• Current Draw @ 24V: 2 mA
• Total Backplane Power: 0.56 W
• Power Dissipation (Max): 5.1 W at 60°C
• Weight: 0.32 kg
• Manufacturer: Allen-Bradley by Rockwell Automation

Electrical & Functional Characteristics

• On-State Voltage: 10–30V AC
• Off-State Voltage (Max): 5V
• On-State Current (Min): 5 mA at 10V AC, 60 Hz
• On-State Current (Max): 12 mA at 30V AC, 60 Hz
• Off-State Current (Max): 2.75 mA
• Inrush Current (Max): 250 mA
• Input Impedance (Max): 2.5 kΩ at 30V AC, 60 Hz
• Cyclic Update Time: 200 µs to 750 ms
• Change of State: Software configurable
• Timestamp of Inputs: ±200 µs
• Isolation Voltage: 250V continuous (basic insulation), inputs-to-backplane and input group-to-group; routine tested at 1350V AC for 2 seconds
• Status Indicators: Module status and I/O status LEDs

System Integration & Compatibility

• Primary Platform: ControlLogix 1756 chassis
• Software: RSLogix 5000 / Studio 5000 Logix Designer
• Configuration: Software-configurable; no physical DIP switches required
• Hot Swap: Supports removal and insertion under power (RIUP)
• Keying: Electronic keying prevents incorrect module insertion
• Removable Terminal Block: 1756-TBNH (NEMA screw clamp) or 1756-TBSH (spring clamp), sold separately
• Wire Size: Single: 0.33–2.1 mm² (22–14 AWG); Double: 0.33–1.3 mm² (22–16 AWG)
• Terminal Block Torque: 1.36 N·m (12 lb·in)
• Related Parts: 1756-IN16K (conformal coated kit), 1756-IA16 (120V AC input), 1756-IM16I (240V AC isolated input)

Environmental & Operational Limits

• Operating Temperature: 0°C to 60°C (32°F to 140°F)
• Storage Temperature: -40°C to +85°C (-40°F to 185°F)
• Humidity: 5% to 95% RH, non-condensing
• Vibration: 2G, 10 to 500 Hz
• Shock: 30G operating; 50G non-operating
• Emissions: CISPR 11, Group 1, Class A
• ESD Immunity: 6 kV contact discharge; 8 kV air discharge (IEC 61000-4-2)
• Radiated RF Immunity: 10 V/m (IEC 61000-4-3)
• EFT/B Immunity: ±4 kV at 5 kHz on signal ports (IEC 61000-4-4)
• Surge Transient Immunity: ±1 kV line-line (DM) and ±2 kV line-earth (CM) on signal ports (IEC 61000-4-5)
• Conducted RF Immunity: 10 V rms (IEC 61000-4-6)
• Temperature Code: T3C (North American); T3 (IEC)
• Approvals: UL, CSA, CE, C-Tick, ATEX, FM (Class I Division 2)

Industrial Applications

Widely deployed in manufacturing, material handling, packaging, automotive assembly, food & beverage processing, and general industrial automation where 24V AC digital inputs from limit switches, proximity sensors, pushbuttons, and selector switches are required.

Frequently Asked Questions

What is the 1756-IN16 used for?

It is a 16-point 24V AC digital input module for ControlLogix systems, interfacing with AC field devices such as limit switches, proximity sensors, and pushbuttons.

What is the difference between 1756-IN16 and 1756-IA16?

The 1756-IN16 accepts 10–30V AC (24V AC nominal). The 1756-IA16 accepts 74–132V AC (120V AC nominal). Choose based on your field device voltage.

What terminal block do I need?

The 1756-TBNH (20-pin NEMA screw clamp) or 1756-TBSH (20-pin spring clamp) removable terminal block is required and sold separately.

Can I hot-swap this module?

Yes — the 1756-IN16 supports RIUP (removal and insertion under power) when used in a compatible ControlLogix chassis.

What are the related part numbers?

• 1756-IA16 — 16-point 120V AC digital input
• 1756-IM16I — 16-point 240V AC isolated digital input
• 1756-IN16 — 16-point 24V AC digital input (this part)
• 1756-IN16K — Conformal coated version with terminal block kit
• 1756-TBNH — 20-pin NEMA screw clamp terminal block
• 1756-TBSH — 20-pin spring clamp terminal block