Product Overview
The Allen-Bradley 1756-IA16 is a 16-point digital AC input module from the ControlLogix platform, engineered for reliable signal acquisition in demanding industrial environments. It interfaces with discrete devices such as limit switches, pushbuttons, and auxiliary contacts, converting 120VAC signals into logic-level data for your PLC. With a wide operating voltage range of 74-132VAC and a frequency range of 47-63 Hz, this module ensures stable performance across varying power conditions.
Designed for seamless integration into any ControlLogix chassis, the 1756-IA16 offers two isolated groups of eight inputs each, providing flexible wiring and simplified troubleshooting. Its user-selectable input filters (9 ms or 18 ms for ON transitions; 1 ms or 2 ms for OFF transitions) allow you to tailor response times to your specific application needs, reducing nuisance trips caused by electrical noise.
Technical Specifications
The following table summarizes the key parameters of the 1756-IA16, based on official Rockwell Automation data:
| Parameter |
Value |
| Manufacturer |
Rockwell Automation / Allen-Bradley |
| Series |
ControlLogix |
| Part Number |
1756-IA16 |
| Module Type |
Digital AC Input Module |
| Number of Inputs |
16 (2 groups of 8) |
| Nominal Input Voltage |
120VAC |
| Operating Voltage Range |
74-132VAC |
| Input Frequency |
47-63 Hz |
| ON-state Current (min) |
5 mA @ 79VAC, 47-63 Hz |
| ON-state Current (max) |
13 mA @ 132VAC, 47-63 Hz |
| Off-state Current (max) |
2.5 mA |
| Cyclic Update Time |
200 µs – 750 ms |
| Signal Delay – ON transition |
Hardware: 8 ms max + filter (9 or 18 ms) |
| Signal Delay – OFF transition |
Hardware: 10 ms max + filter (1 or 2 ms) |
| 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 |
| Thermal Dissipation |
18.41 BTU/hr |
| Removable Terminal Block |
1756-TBNH or 1756-TBSH |
Applications and Use Cases
The 1756-IA16 is ideal for monitoring AC-powered devices in a wide range of industries:
-
Manufacturing lines: Detect the status of motor starters, solenoid valves, and conveyor presence sensors.
-
Material handling: Monitor limit switches and safety interlocks on cranes and hoists.
-
Process control: Interface with legacy 120VAC control circuits in chemical or food processing plants.
Thanks to its robust 74-132VAC input range, the 1756-IA16 tolerates voltage fluctuations common in industrial power supplies, minimizing false readings and downtime.
Installation & Setup Guidance
Installing the 1756-IA16 is straightforward:
- Insert the module into any ControlLogix chassis slot. It is compatible with all ControlLogix chassis.
- Select an appropriate removable terminal block (1756-TBNH or 1756-TBSH) and wire the field inputs according to your wiring diagram.
- Configure the module in your ControlLogix programming software. Set the input filter times (9/18 ms for ON, 1/2 ms for OFF) based on your signal characteristics.
- Apply power and verify channel status via the front-panel LEDs.
Ensure that the AC supply is within the rated range (74-132VAC) and that all wiring complies with local electrical codes.
Maintenance & Reliability
The 1756-IA16 is built for long service life with minimal maintenance. However, periodic checks are recommended:
- Inspect terminal block connections for tightness and signs of corrosion every 6-12 months.
- Keep the module enclosure clean and free of dust to maintain proper airflow and cooling.
- Verify that the backplane power supply is stable and within specifications.
Routine inspections help prevent unexpected failures and extend the module's operational life, reducing total cost of ownership.
Compatibility & Integration
The 1756-IA16 is designed exclusively for the ControlLogix platform. It works with any ControlLogix chassis and is fully compatible with Rockwell Automation's Studio 5000 Logix Designer software. The module does not require any external power supply other than the backplane, simplifying integration.
Selection Guide & Purchasing Advice
Before purchasing, verify that your application requires 120VAC input signals and that your chassis has an available slot. Confirm the terminal block type (1756-TBNH or 1756-TBSH) you need, as these are sold separately. For genuine, factory-tested Allen-Bradley 1756-IA16 modules, visit PLC Source PRO for competitive pricing and fast shipping.