Product Introduction
The Allen-Bradley 1756-IM16I is a high-performance isolated digital input module designed for the ControlLogix platform. It delivers reliable signal acquisition in demanding industrial environments where electrical isolation and noise immunity are critical. This module monitors AC input signals from field devices such as limit switches, pushbuttons, and proximity sensors, converting them into logic signals for your control system.
Technical Specifications
| Specification |
Value |
| Manufacturer |
Rockwell Automation |
| Brand |
Allen-Bradley |
| Part Number |
1756-IM16I |
| Series |
ControlLogix |
| Module Type |
Isolated Digital Input Module |
| Inputs |
16 Individually Isolated Inputs |
| Input Voltage |
240 Volts AC |
| Operating Voltage Range |
159-265 Volts AC |
| Input Delay Time |
Programmable 9 or 18 milliseconds |
| Minimum Operating Current |
5 milliamperes at 159 Volts AC, 60 Hertz |
| Maximum Operating Current |
13 milliamperes at 265 Volts AC, 60 Hertz |
| Maximum Input Current, Off-State |
2.5 milliamperes |
| Power Dissipation (Max) |
5.8 Watts at 60 degrees Celsius |
| Removable Terminal Block(s) |
1756-TBCH, 1756-TBS6H |
| UPC |
10612598171344 |
Key Features & Benefits
-
Per-point isolation – Each of the 16 inputs is individually isolated, preventing ground loops and improving signal integrity.
-
Flexible input delay – Programmable delay times (9 or 18 ms) allow you to filter noise and debounce signals effectively.
-
Wide AC range – Operates from 159 to 265 VAC, accommodating varying power conditions.
-
Hot-swappable terminal blocks – Compatible with 1756-TBCH and 1756-TBS6H RTBs for quick maintenance.
-
Low power dissipation – Max 5.8 W at 60°C keeps heat generation manageable in dense cabinets.
Industry Applications
The Allen-Bradley 1756-IM16I excels in applications requiring robust AC input sensing with high isolation. Typical use cases include:
-
Manufacturing lines – Monitoring motor starter auxiliary contacts and safety interlocks.
-
Material handling – Detecting conveyor jam switches and pallet position sensors.
-
Process control – Reading valve limit switches and pump status signals in harsh environments.
Its ability to handle high AC voltages and provide per-point isolation makes it ideal for retrofitting older systems where electrical noise is a concern.
Installation & Setup
To install the 1756-IM16I, first ensure the chassis power is off. Insert the module into any available slot in a 1756 ControlLogix chassis. Use either the 1756-TBCH or 1756-TBS6H 36-pin removable terminal block to wire field inputs. Follow the wiring diagram provided in the user manual, ensuring correct phase and neutral connections. Configure the input filter times and delay settings via your ControlLogix programming software to match your application requirements.
Maintenance & Reliability
Routine maintenance is minimal. Periodically inspect the terminal block connections for tightness and check for signs of overheating or corrosion. Ensure the ambient temperature stays within the rated range to maintain optimal performance. Because the module has no moving parts, its expected service life is long, reducing downtime and replacement costs.
Compatibility & Integration
The 1756-IM16I is designed for the Allen-Bradley ControlLogix platform and works seamlessly with 1756 backplanes and controllers. It supports standard ControlLogix communication protocols (such as EtherNet/IP, ControlNet, and DeviceNet) when used with the appropriate communication modules. This integration ensures easy data exchange with your PLC and HMI systems.
Buying Guide
Before purchasing, verify that your system requires an AC input module with isolated points. Confirm the terminal block type you need (1756-TBCH or 1756-TBS6H). PLC Source PRO offers genuine Allen-Bradley 1756-IM16I modules with fast shipping and competitive pricing, ensuring you get a reliable replacement or upgrade for your automation needs.