Overview
The Allen-Bradley 1746-NO4I is a 4-point analog output module engineered for the SLC 500 modular controller platform. This module provides four isolated current outputs in the 0–20 mA range, making it ideal for controlling analog devices such as proportional valves, variable frequency drives, actuators, and process instrumentation. The 1746-NO4I operates on 24V DC backplane power and supports optional external 24V DC supply connections.
Key Features
- 4-Channel Analog Outputs: Four independent 0–20 mA current-loop channels for simultaneous multi-device control
- 14-Bit Resolution: 14-bits resolution ensures precise analog output control
- Flexible Power Supply: Connections for user-supplied 24V dc power supplies; when external 24V dc power is used, the module only draws 5V dc current from the SLC backplane
- SLC 500 Native Compatibility: Installs directly into any standard SLC chassis, providing four isolated current outputs
- Rack-Mount Design: Compact form factor for space-efficient panel integration
- Fast Step Response: Step response at 95% of 2.5 ms for time-sensitive applications
Technical Specifications
- Output Channels: 4 outputs
- Output Type: Analog current loop
- Output Range: 0 to 20 mA
- Resolution: 14 bits
- Backplane Voltage (Standard): 24 Volts DC
- Backplane Current Draw (5V DC): 55 mA
- Backplane Current Draw (24V DC): 195 mA
- Electrical Isolation: Full electrical isolation for field wiring, rated up to 500V DC
- Operating Temperature Range: 0 to 60 degrees Celsius
- Storage Temperature Range: -40 to 85 degrees Celsius
- Wiring Specifications: Requires shielded Belden #8761 cable; maximum permitted wire size is #14 AWG
- Mounting: Slotted rail mount (1746 SLC chassis)
- Weight: 0.44 lbs
- Product Family: SLC 500
- Status: Discontinued by manufacturer
Typical Applications
Process control, machine automation, and applications requiring precise analog output regulation. Common use cases include:
- Proportional valve control in hydraulic and pneumatic systems
- Variable frequency drive (VFD) setpoint adjustment
- Process instrumentation loop control (4–20 mA transmitters)
- Actuator positioning and speed regulation
- Legacy SLC 500 system modernization and retrofit
Compatibility & Replacements
Compatible With
- SLC 500 modular chassis (1746-A4, 1746-A10, 1746-A13)
- SLC 500 modular power supplies (1746-P1, 1746-P2, 1746-P5, 1746-P6)
- Allen-Bradley programming software: RSLogix 500
- EtherNet/IP communications gateway modules
Replaces / Drop-In Replacement For
- 1746-NO4I (exact same model — use for spares and redundancy)
- 1746-NO4V (analog output module variant; verify compatibility with system integrator)
- Compatible with legacy SLC 500 systems from mid-1990s through 2010s
Works With
- Programming Platforms: RSLogix 500, RSLogix Emulate 500
- Communication Protocols: SLC 500 backplane I/O, optional DH-485, DH+
- Ecosystems: Rockwell Automation CompactLogix legacy upgrades, MicroLogix analog expansion
