Overview
The Allen-Bradley 1756-IB16I is a discrete digital input module designed for ControlLogix automation systems. It provides 16 individually isolated input channels that accept DC signals from industrial field devices such as pushbuttons, switches, sensors, and auxiliary contacts. Per-point isolation enhances noise immunity and increases system reliability in demanding industrial environments.
Key Features
- 16 individually isolated DC input channels for enhanced signal integrity
- Accepts 10–30VDC input signals with nominal 24VDC rating
- Per-point isolation voltage of 250V continuous for maximum protection
- Single-slot module design for efficient ControlLogix chassis space utilization
- User-selectable input filter times (0, 1, 2, 9, or 18 ms) for flexible noise rejection
- Full software configuration via RSLogix 5000 / Studio 5000
- Built-in status indicators for input, communication, and module health
Technical Specifications
The module operates across a wide input voltage range and maintains minimal power draw from the backplane:
- Input Channels: 16 (individually isolated)
- Voltage Category: 12/24V DC sink/source
- Operating Voltage Range: 10–30V DC
- Nominal Input Voltage: 24V DC
- Current Draw @ 5.1V: 100 mA
- Current Draw @ 24V: 3 mA
- Maximum Power Dissipation: 5 W @ 60°C
- Thermal Dissipation: 17.05 BTU/hr
- Isolation Voltage: 250V continuous
- Maximum Inrush Current: 250 mA peak (decaying to <37% in 22 ms)
- Response Time (OFF to ON): 1 ms hardware delay + selectable filter (0, 1, or 2 ms)
- Response Time (ON to OFF): 4 ms hardware delay + selectable filter (0, 1, 2, 9, or 18 ms)
- Operating Temperature: 0–60°C
- Mounting: Single-slot 1756 ControlLogix chassis backplane
- Module Width: Single slot
Typical Applications
The 1756-IB16I is widely deployed in:
- Discrete signal acquisition from industrial sensors and switches
- Local, remote, and distributed I/O architectures within ControlLogix networks
- Process control and machine automation systems requiring per-channel isolation
- Heavy industrial facilities where EMI/RFI noise immunity is critical
- Monitoring binary ON/OFF states from field devices for real-time controller processing
Compatibility & Replacements
The 1756-IB16I is compatible with all standard ControlLogix chassis platforms and integrates with existing automation networks via the ControlLogix backplane. Firmware updates and Add-On Profiles (AOP) for 1756 Discrete I/O are available from Rockwell Automation. The module supports removal and insertion under power, enabling maintenance without system shutdown. Compatible Removable Terminal Blocks (RTB) include the 1756-TBCH and 1756-TBS6H for flexible field termination. This module is internationally certified (CE, CSA, UL, RCM, IECEx, ATEX, China CCC) and remains an active product in the ControlLogix family with ongoing technical support from Rockwell Automation.
