Overview
The Allen-Bradley 1746-NO4I is a 4-point analog output module designed for the SLC 500 product platform. This module uses a 16-bit 2’s complementary binary format and is compatible with both fixed and modular style SLC 500 hardware. It has 4 current outputs that have an output range of 0 to +20 mA with full-scale current output of 21 mA. The module mounts directly into standard SLC 500 chassis, making it a reliable choice for process control and machine automation applications requiring precise analog output regulation.
Key Features
- 14-bit resolution via R-2R Ladder conversion method
- Embedded selector switch for power supply source selection—internal (backplane) or external 24V ±10%
- Removable terminal block for simplified wiring and ease of module replacement; uses shielded communication cable
- LED status indicator for on-board diagnostics
- Capable of controlling modulating instruments and devices; commonly used with Proportional-Integral-Derivative (PID) controllers
Technical Specifications
- Output Configuration: 4 outputs (0…20mA)
- Output Range: 0 to +20 mA with full-scale current output of 21 mA
- Resolution: 14 bits
- Backplane Current Draw: 55mA at 5V DC or 195mA at 24V DC
- External Power Supply: 24V ±10% (26.6…26.4V dc)
- Load Range: 0 to 500 ohms with maximum load reactance of 100 µH
- Step Response: 2.5 milliseconds at 95%
- Operating Temperature: 0 to 60 degrees Celsius
- Storage Temperature: -40 to 85 degrees Celsius
- Backplane Isolation: 500 Volts DC
- Mounting Style: Rack Mount into SLC 500 Chassis
- Terminal Style: Screw-terminal connections
- Accuracy Drift: ±70 ppm/degree Celsius of full-scale accuracy
- Enclosure: Open enclosure; compatible with 1746 chassis only
- Weight: 0.44 lbs
Typical Applications
The 1746-NO4I provides current-loop output signals for controlling industrial devices such as valves, drives, actuators, and instrumentation requiring 0–20 mA signals. This module is widely used in process control, machine automation, and applications requiring precise analog output regulation. If used with a Proportional-Integral-Derivative controller, the analog output is assigned to represent the Control Output (CO) of the PID controller. For manual loading stations, the analog output represents the manual command entered by the operator. The module may also be used to re-transmit an important signal to a single or multiple device for indication, data logging, and signal conversion.
Compatibility & Replacements
Compatible With
- SLC 500 fixed or modular style hardware
- Standard 1746 SLC 500 Chassis (CompactLogix not compatible)
- SLC 5/01, SLC 5/02, SLC 5/03, SLC 5/04, SLC 5/05 controllers
- PID controllers and analog-controlled field instrumentation
Replaces / Drop-In Replacement For
- 1746-NO4I Series A (earlier revisions)
- This module is comparable with 1746-NO8I (8-point version for dual-channel applications)
- 1747-NO4I (alternate part designation)
Works With
- RS-Logix 500 (ladder logic programming for SLC 500)
- Studio 5000 Logix Designer (via SLC 500 legacy support)
- EtherNet/IP communication via appropriate adapters
- Hardwired analog signal wiring (0–20 mA loop power not supplied by module)
- External 24 VDC power supplies meeting N.E.C. Class 2 specification
