Overview
Allen-Bradley 1746-NO4I is a 4-channel analog output module engineered for the SLC 500 control platform. This module provides isolated current-loop output signals ideal for driving analog-controlled industrial devices such as proportional valves, variable frequency drives, actuators, and precision instrumentation requiring standard 0–20 mA signals. The 1746-NO4I installs directly into any standard SLC chassis and integrates seamlessly with SLC processors and communication adapters across single or multi-chassis systems.
Key Features
- 4 isolated current output channels — each delivering 0–20 mA with 5% overrange capability (full scale up to 21 mA)
- 14-bit resolution — ensures precise analog control and repeatability in process automation
- Fast update time — 512 microsecond response enables rapid closed-loop control
- Optical isolation & filtering — reduces electrical noise and ensures stable signal integrity across long cable runs
- Screw-terminal connections — field-proven reliability for industrial environments
- Standard SLC environmental ratings — operates 0–60 °C with industrial vibration tolerance and high dielectric withstand levels
Technical Specifications
Output Specifications:
- Output Range: 0 to +20 mA DC per channel
- Full Scale: Up to 21 mA (5% overrange)
- Resolution: 14-bit converter
- Update Time: 512 microseconds
- Backplane Current Draw: 55 mA @ 5 VDC; 195 mA @ 24 VDC
- Channel Isolation: Optical isolation per channel
- Field Wiring Isolation: 500 VDC
- Accuracy: ±0.208% of full scale @ 25 °C ambient
- Operating Temperature: 0 to 60 °C
- Connector Type: Screw-terminal block with LED status indicator
- Module Format: Single-slot SLC 500 I/O card
Typical Applications
- Proportional valve control in hydraulic systems
- Variable frequency drive (VFD) speed commands
- Pressure and flow actuator modulation
- Process instrumentation feedback and PID loop closure
- Analog sensor signal transmission for remote monitoring
- Multi-axis motion control requiring coordinated analog outputs
Compatibility & Replacements
Compatible With
- SLC 500 fixed and modular chassis (1746 backplane)
- SLC 5/01, 5/02, 5/03, 5/04, 5/05 processors
- SLC 500 communication adapters for multi-chassis networking
- RSLogix 500 programming software
- Standard 24 VDC industrial control networks
Replaces / Drop-In Replacement For
The 1746-NO4I is a direct replacement for existing 1746-NO4I units across SLC 500 systems. Verify your current module revision (Series A specified) for hardware compatibility before ordering.
Works With
- RSLogix 500 IDE for SLC 500 programming
- Allen-Bradley PLC-5 networks (via communication adapters)
- Ethernet/IP gateways for remote I/O integration
- Standard 4–20 mA instrumentation loops
- Proportional control valve drivers
