Overview
The Allen-Bradley 1746-IA16 is a 16-channel discrete digital input module designed for the SLC 500 modular PLC family. This Series C module accepts sixteen 100/120VAC input signals and provides individual optical isolation and built-in surge protection for reliable operation in industrial environments. The 1746-IA16 is ideal for applications requiring multiple AC-sourced discrete inputs such as limit switches, proximity sensors, and pushbuttons.
Key Features
- 16 individually isolated AC input channels (100/120VAC rated)
- Operating voltage range: 85–132VAC at 47–63Hz
- 16 LED status indicators for real-time input monitoring
- Built-in optical isolation and surge protection
- Low signal delay: 35ms ON, 45ms OFF (maximum)
- Removable screw-clamp terminal block for field wiring
- Rack-mount form factor with SLC 500 backplane connector
Technical Specifications
- Input Voltage: 85–132VAC, 50/60Hz
- Number of Inputs: 16 points (grouped as 16 points per common)
- Nominal Input Current: 12mA at 120VAC
- Maximum Inrush Current: 0.8A for 500ms
- Off-State Voltage (Maximum): 30VAC
- Off-State Current (Maximum): 2mA
- Signal Delay (Maximum): ON = 35ms, OFF = 45ms
- Backplane Current at 5VDC: 85mA
- Backplane Isolation: 1500VAC
- Operating Temperature: 0–60°C
- Weight: 0.40 lbs
- Terminal Style: Screw-clamp removable block
- Mounting: Rack-mount (SLC 500 chassis)
Typical Applications
The 1746-IA16 is commonly used for discrete input monitoring in:
- Machinery automation and process control
- HVAC and building automation systems
- Packaging and material handling equipment
- General industrial control panels requiring AC-sourced limit switches and sensors
- Legacy SLC 500 system upgrades and maintenance
Compatibility & Replacements
Compatible With
- Allen-Bradley SLC 500 modular processor chassis (1746 I/O rack)
- SLC 5/03, SLC 5/04, SLC 5/05 processors
- Studio 5000 Logix Designer (for legacy system documentation and migration)
- RS Logix 500 programming software
- 24VDC backplane power supplies (standard SLC 500 chassis)
Replaces / Drop-In Replacement For
Verify compatibility with your system integrator before ordering. The 1746-IA16 Series C is a direct replacement for identical part numbers from earlier series (A, B) when electrical specifications match.
Works With
- SLC 500 modular I/O systems
- AC-sourced discrete sensors (120VAC limit switches, proximity sensors, pushbuttons)
- Standard PLC wiring practices with field-supplied external power
- Preventive maintenance and spare-parts inventory management
