Hands-On Overview
The Allen Bradley 1746-NO4I is a four-channel analog output module engineered for use with SLC 500 PLC systems, designed to deliver precise analog signals for controlling process equipment such as valves, drives, and actuators.
This module is favored among industrial control engineers for its rugged build, precise output resolution, and easy integration within the SLC 500 chassis. It converts digital values from the controller into proportional current outputs, enabling fine-tuned control in demanding process automation applications.
Whether used for flow regulation, temperature control, or speed adjustment, the 1746-NO4I stands as a reliable bridge between logic control and the physical process layer.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Allen Bradley / Rockwell Automation |
| Product Type | Analog Output Module |
| Series | SLC 500 |
| Number of Channels | 4 |
| Output Type | Current (4–20 mA, 0–20 mA) |
| Resolution | 14-bit (1 part in 16,384) |
| Accuracy | ±0.1% of full scale at 25°C |
| Output Load Resistance | 0–750 Ω |
| Isolation Voltage | 500 V DC between field and backplane |
| Conversion Rate | 1 ms per channel (typical) |
| Backplane Current | 55 mA at 5 VDC, 80 mA at 24 VDC |
| Power Dissipation | 2.3 W |
| Operating Temperature | 0°C to 60°C (32°F to 140°F) |
| Storage Temperature | -40°C to 85°C (-40°F to 185°F) |
| Humidity | 5–95% non-condensing |
| LED Indicators | Module Status (OK/Fault) |
| Dimensions (H × W × D) | 127 mm × 31 mm × 120 mm (5.0 in × 1.2 in × 4.7 in) |
| Weight | 0.22 kg (0.49 lb) |
| Mounting Type | SLC 500 Chassis Slot |
| Certifications | UL, CE, CSA |
Industrial Applications
The 1746-NO4I is widely deployed in analog process control and instrumentation systems, including:
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Variable Speed Drive Control – outputs analog signals to regulate motor speed.
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Valve Positioning Systems – sends proportional current signals to control flow valves.
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Temperature Control Loops – interfaces with analog actuators or transmitters.
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Batch and Continuous Process Automation – ideal for water treatment, chemical mixing, and food processing.
Its robust signal stability ensures consistent and repeatable performance even in electrically noisy industrial environments.
Why Engineers Choose 1746-NO4I
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Precision Analog Output: 14-bit resolution ensures fine control accuracy.
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Rugged Construction: Designed for demanding process and manufacturing environments.
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Simple Integration: Seamlessly fits into existing SLC 500 PLC racks.
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Electrical Isolation: Protects both the PLC and field devices from transients.
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Low Maintenance: LED indicators and diagnostic feedback simplify troubleshooting.
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