Overview
The Allen-Bradley 1746-ITB16 is a digital DC sinking input module designed for the SLC 500 modular chassis platform. Unlike standard input modules, the 1746-ITB16 is optimized for fast-response, high-frequency signal capture, making it essential for applications requiring rapid input detection. This module integrates 16 input channels and connects directly to the SLC 500 backplane, providing 5V DC power via the chassis with no external backplane power required.
Key Features
- 16 Digital Input Channels: Capture and monitor up to 16 independent DC input signals
- Fast Response Capability: Processes pulse signals up to 1 kHz at 100 µsec polling intervals when used with SLC 5/03 or SLC 5/04 processors
- Gray Code Encoder Support: Compatible with 845D encoders; pulse frequency reaches 2 kHz with gray code inputs
- No Door Design: Provides unrestricted access to terminal blocks and internal components for quick maintenance
- Removable Terminal Blocks: Simplifies module replacement without disconnecting field wiring
- Optical Isolation & Filtering: Reduces electromagnetic noise and improves signal integrity
- LED Status Indicators: Visual feedback for each input channel state
Technical Specifications
- Input Voltage Range: 10–30V DC (sinking)
- Number of Inputs: 16 channels, 16 points per common
- Nominal Input Current: 8 mA @ 24V DC
- Off-State Input Current (Max): 1.5 mA
- Off-State Input Voltage (Max): 5V DC
- Signal On-Delay (Max): 0.1 ms @ 24V DC
- Signal Off-Delay (Max): 0.25 ms @ 24V DC
- Backplane Current Load: 85 mA @ 5V DC
- Maximum Power Dissipation: 3.6 W
- Operating Temperature Range: 32–140°F (0–60°C)
- Relative Humidity: 5–95% non-condensing
- Mounting: SLC 500 modular chassis slot
Typical Applications
The 1746-ITB16 is deployed in time-sensitive industrial automation environments including:
- High-speed assembly line control and monitoring
- Pulse counting from encoders and proximity sensors
- Material handling systems with rapid sensor feedback
- Motion control triggering and position verification
- HVAC and process control interlocks requiring fast response
- Conveyor and sorting applications with encoder feedback
Compatibility & Replacements
Compatible With
- Allen-Bradley SLC 500 modular chassis (all types)
- SLC 5/01, 5/02, 5/03, 5/04, 5/05 processors
- SLC 500 Ladder Logic programming environment
- Allen-Bradley 845D Absolute Gray Code Encoder
- Any 10–30V DC sinking sensor or switch input
Replaces / Drop-In Replacement For
The 1746-ITB16 is the direct successor to earlier fast-response input modules in the 1746 family. It directly replaces other 16-channel fast DC input configurations when exact part compatibility is required. Verify your chassis slot availability and processor compatibility before ordering.
Works With
- SLC 500 Modular Hardware (1746-chassis)
- RSLogix 500 and Rockwell Automation Studio 5000 programming
- Discrete Input Interrupt (DII) instructions for high-speed capture
- Standard Ladder Logic I/O addressing
