Allen-Bradley 1746-NO4I Analog Output Module

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

Industrial Applications

The 1746-NO4I is widely deployed in analog process control and instrumentation systems, including:

• Variable Speed Drive Control – outputs analog signals to regulate motor speed.

• Valve Positioning Systems – sends proportional current signals to control flow valves.

• Temperature Control Loops – interfaces with analog actuators or transmitters.

• 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

• Precision Analog Output: 14-bit resolution ensures fine control accuracy.

• Rugged Construction: Designed for demanding process and manufacturing environments.

• Simple Integration: Seamlessly fits into existing SLC 500 PLC racks.

• Electrical Isolation: Protects both the PLC and field devices from transients.

• Low Maintenance: LED indicators and diagnostic feedback simplify troubleshooting.

FAQs

1. Can each channel output independently?

   Yes, each of the four channels can be configured and operated independently.

2. What’s the maximum load resistance per channel?

   Up to 750 Ω without affecting output accuracy.

3. Is the module hot-swappable?

   No, power must be removed before installing or removing the module.

4. How does the 1746-NO4I connect to field devices?

   It uses standard screw terminals on the I/O chassis for each output channel.

5. Does it support voltage output?

   No, it is current-output only (4–20 mA, 0–20 mA).

6. How is scaling handled in the PLC program?

   Scaling is defined in the ladder logic to match the 4–20 mA output range.

7. What’s the effect of temperature on accuracy?

   ±0.005% of full scale per °C deviation from 25°C.

8. Is there protection against short circuits?

   Yes, each output is electronically protected against short circuits and overcurrent.

9. Can it drive more than one device per channel?

   Only if total resistance remains within 750 Ω.

10. Which software is used for configuration?

    RSLogix 500 or equivalent SLC 500 programming software.