What Makes the 1756-IA16 the Right Choice for Your ControlLogix System?
Is your ControlLogix chassis waiting on a reliable AC input module to bring field signals into the controller? The Allen-Bradley 1756-IA16 answers that need directly. This ControlLogix digital AC input module from Rockwell Automation provides Sixteen (16) discrete input channels, arranged in Two (2) groups of Eight (8) points each, so you can wire multiple field devices without adding extra cards.
Built for 120VAC Field Signals
The 1756-IA16 operates at a nominal 120VAC with an operating voltage range of 74-132VAC and a frequency of 47-63 Hz. That range covers the real-world voltage swings found on plant floors. Each channel accepts a minimum ON-state current of 5 mA at 79V AC and a maximum of 13 mA at 132V AC, while the OFF-state current stays at 2.5 mA max. The module tolerates a maximum inrush current of 250 mA peak, decaying to less than 37% in 22 milliseconds without activation.
Technical Specifications
| Specification | Value |
|---|---|
| Manufacturer | Allen-Bradley / Rockwell Automation |
| Series | ControlLogix |
| Module Type | Digital AC Input Module |
| Number of Inputs | 16 (Two groups of 8) |
| Input Voltage Range | 74-132VAC |
| Nominal Input Voltage | 120VAC |
| Frequency | 47-63 Hz |
| ON-state Current | 5 mA @ 79V AC to 13 mA @ 132V AC |
| OFF-state Current | 2.5 mA max |
| Backplane Current (5.1VDC) | 100 mA |
| Backplane Current (24VDC) | 2 mA |
| Total Backplane Power | 0.58 W |
| Power Dissipation (Max) | 5.8 W @ 60 °C |
| Removable Terminal Block | 1756-TBNH or 1756-TBSH |
Signal Delay and Filtering
The 1756-IA16 gives you control over how fast inputs respond. The ON transition carries a hardware delay of 8 ms max plus a user-selectable filter time of 9 ms or 18 ms. The OFF transition uses a hardware delay of 10 ms max plus a selectable filter time of 1 ms or 2 ms. The cyclic update time spans 200 µs to 750 ms. These settings let you tune the module to reject noise or catch fast events, depending on the application.
Where the 1756-IA16 Fits
This module suits oil and gas, water treatment, and general industrial automation where 120VAC discrete signals dominate. Typical uses include reading auxiliary contacts on motor starters, monitoring limit switches, and capturing status from pushbuttons and selector switches. Because the 1756-IA16 is compatible with any ControlLogix chassis, it drops into existing racks without special adapters.
Installation and Maintenance Notes
Use the 1756-TBNH or 1756-TBSH removable terminal block housing for field wiring. Each channel has an individual status LED, so you can verify signal state at a glance during commissioning. For maintenance, inspect terminal connections periodically and follow the manufacturer’s safety manual. Keep the chassis environment within the module’s rated thermal limits to protect long-term reliability.
Sourcing the 1756-IA16
When a line goes down, waiting weeks for a spare is not an option. Oil AutoTech focuses on fast dispatch, worldwide delivery for oil, gas, and industrial automation spares. Our team can help you confirm the exact configuration you need. Contact Oil AutoTech today for pricing and availability.
