Overview
The Allen-Bradley 1746-IV16 Series C is a 16-point discrete DC input module from the Rockwell Automation SLC 500 family of programmable controllers. This sourcing input module accepts 24V DC signals from industrial sensors, switches, and contactors, converting them to digital data stored in the processor’s image table. Compatible with all fixed and modular SLC 500 processors, it provides reliable signal acquisition for material handling, HVAC control, assembly operations, process control, and motion control applications.
Key Features
- 16 sourcing input channels — all points grouped under a single common, with optional multi-common configurations available in related modules
- 24V DC nominal operation — accepts 10–30V DC input range for industrial voltage tolerance
- Fast signal response — 0.3 ms ON-delay, 0.5 ms OFF-delay for real-time discrete sensing
- Removable terminal block (RTB) — simplifies field replacement and wiring reconfiguration without panel rewiring
- LED status indicators — one per input channel for quick troubleshooting and operational visibility
- Compact single-slot design — occupies one slot in the 1746 chassis, maximizing available I/O density
- Optical isolation — protects backplane and processor from noise and transients
Technical Specifications
The module integrates seamlessly into legacy and existing SLC 500 installations. Key performance parameters:
- Input voltage: 24V DC nominal (10–30V DC sourcing range)
- Signal delay: 0.3 ms ON, 0.5 ms OFF (typical)
- Backplane current draw: 85 mA @ 5V DC; 0 mA @ 24V DC
- Off-state current: 1 mA maximum
- Nominal input current: 8 mA @ 24V DC
- Operating temperature: 0–60°C (32–140°F)
- Humidity: 5–95% non-condensing
Typical Applications
The 1746-IV16 is widely used in industrial automation environments requiring discrete digital input sensing:
- Conveyor and material handling line controls
- HVAC system monitoring and interlocks
- High-speed assembly operation sensing
- Process and batch control systems
- Small to mid-scale motion control and sequencing
- SCADA and remote I/O expansion (supports expansion and remote I/O racks)
Compatibility & Replacements
The 1746-IV16 is compatible with all SLC 500 processor types, including the SLC 5/01, 5/02, 5/03, 5/04, and 5/05. It mounts in any available slot of the 1746 chassis as either a local or remote I/O module. The Series C revision is the latest standard offering. Related modules in the SLC 500 discrete input family include the 1746-IV8 (8-point), 1746-IV32 (32-point), and 1746-ITV16 (fast-response 16-point). Output complements include the 1746-OB16 (16-point DC output) and 1746-OV16 (16-point AC output). This module is ideal for customers maintaining legacy SLC 500 systems or integrating into existing installations where proven 24V DC sourcing input capability is required.
