ALLEN-BRADLEY 1791-16AO Ac Block Module 16-INPUT 120V I/o

( Brand: Allen-bradley ), ( Manufacturer Part Number: 1791-16AO ), ( Part Type: Ac Block Module ), ( Condition: Pre-owned Ser.b Missing Din Clip )

Review ALLEN BRADLEY 16-input 120v Ac Block I/o Module

The **Allen-Bradley 1791-16AO 16-Input, 120V AC Block I/O Module** is a high-performance, industrial-grade input module designed to seamlessly integrate with the **CompactLogix, ControlLogix, and other Allen-Bradley PLC platforms** within a robust ControlNet or EtherNet/IP network architecture. This module is engineered to provide reliable and scalable digital input functionality, making it an ideal solution for applications requiring precise monitoring of high-voltage AC signals in demanding industrial environments. With **16 isolated, 120V AC input points**, each channel is capable of handling standard industrial voltage ranges (typically 85 132V AC at 50/60Hz), ensuring compatibility with a wide array of sensors, relays, and control devices. The module features **hardware filtering** to mitigate noise and transient spikes, enhancing signal integrity and reducing false triggering, while its **optically isolated inputs** provide inherent protection against voltage surges and ground loops, safeguarding both the module and connected equipment. Built to meet **NEMA 4X and IP67** environmental standards, the 1791-16AO is constructed with durable materials, including a rugged metal enclosure and corrosion-resistant coatings, allowing it to withstand harsh conditions such as extreme temperatures, humidity, and exposure to dust, oil, and washdown environments. Its **backplane-powered design** eliminates the need for external power supplies, simplifying installation and reducing wiring complexity, while the **hot-swappable architecture** enables seamless replacement without disrupting system operation. The module s **deterministic communication** over ControlNet or EtherNet/IP ensures low-latency data transfer, critical for real-time control applications, and its **compatibility with Rockwell Automation s Studio 5000 software** allows for easy configuration, monitoring, and troubleshooting via intuitive engineering tools. Whether deployed in manufacturing plants, process control systems, or building automation networks, the 1791-16AO delivers a dependable, high-density input solution that enhances system reliability and operational efficiency.

### **Pros and Cons of buying a Allen-Bradley 1791-16AO 16-Input 120V AC Block I/O Module**

1. **High Reliability and Durability** The 1791 series is a well-established product line from Rockwell Automation, known for robust industrial-grade performance. These modules are designed for harsh environments, offering long-term reliability in manufacturing, process control, and automation applications.

2. **Compatibility with Rockwell Automation Systems** The module integrates seamlessly with Rockwell s ControlLogix, CompactLogix, and other PLC platforms, as well as Studio 5000 software. This ensures smooth operation within existing automation ecosystems without requiring major system upgrades.

3. **120V AC Input Capability** The module supports 120V AC inputs, making it suitable for standard North American industrial power distributions. This eliminates the need for additional voltage conversion hardware in many applications.

4. **Block I/O Architecture** The modular design allows for easy expansion and reconfiguration. Users can add or remove I/O blocks as needed without disrupting the entire system, reducing downtime and maintenance costs.

5. **High Input Count (16)** The 16-input configuration provides a good balance between flexibility and space efficiency, making it ideal for applications requiring multiple discrete inputs (e.g., sensors, switches, or limit switches) without overcomplicating wiring.

6. **Support for Both Analog and Digital Signals** While primarily a digital input module, the 1791 series supports mixed I/O configurations, allowing for integration with analog signals when paired with compatible modules (e.g., 1791-ANALOG).

7. **Easy Installation and Wiring** The module features a terminal block design with screw terminals, which simplifies wiring and troubleshooting compared to some newer plug-in I/O options. This can reduce installation time and errors.

8. **Proven Performance in Industrial Environments** The 1791 series has a long history of use in industries such as food and beverage, pharmaceuticals, and manufacturing, where reliability is critical. It is designed to withstand temperature fluctuations, electrical noise, and mechanical stress.

9. **Support for Redundancy and Fault Tolerance** Rockwell Automation offers redundancy solutions (e.g., dual-processor systems) that can be paired with this module to enhance system uptime and safety.

10. **Availability of Spare Parts and Support** As a legacy product, the 1791 series continues to receive support from Rockwell Automation, including spare parts, documentation, and technical assistance. This reduces the risk of obsolescence compared to newer, less-supported modules.

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1. **Legacy Technology** The 1791 series is an older product line (introduced in the 1990s), which means it lacks some of the advanced features found in newer modules (e.g., Ethernet/IP over TSN, higher-speed communication, or integrated diagnostics). While this is not necessarily a drawback for many applications, it may limit future scalability.

2. **Limited Expansion Options** Compared to newer I/O systems (e.g., Allen-Bradley CompactLogix with integrated I/O or modular I/O systems like the 1756 series), the 1791 s block I/O architecture can be less flexible for very large or complex systems. Wiring can become cumbersome in high-density applications.

3. **Higher Cost of Replacement Parts** While the module itself may be affordable, replacement parts (e.g., individual I/O blocks) can become expensive over time, especially if the system is no longer in active production support. Users may need to source parts from third-party suppliers.

4. **No Built-in Diagnostics** Newer I/O modules often include advanced diagnostics (e.g., real-time monitoring of signal integrity, fault isolation, or predictive maintenance alerts). The 1791 series relies on traditional PLC-based diagnostics, which may require additional programming effort to achieve similar functionality.

5. **Limited Analog Support** While the 1791 series supports analog inputs/outputs when paired with specific modules, it is not as integrated as newer systems that offer mixed I/O in a single module (e.g., the 1756 series). This can require additional hardware for analog applications.

6. **Potential for Obsolescence** Rockwell Automation has phased out some older I/O lines in favor of newer architectures (e.g., the 1756 series or CompactLogix). While the 1791 series is still supported, future compatibility with very new software or hardware may be an issue.

7. **Wiring Complexity** The terminal block design, while user-friendly, can lead to more complex wiring in large systems compared to plug-in or backplane-based I/O systems. This may increase installation time and the risk of wiring errors.

8. **No Built-in Isolation for All Inputs** Some newer I/O modules offer individual input isolation for safety and noise immunity. The 1791 series provides isolation for the entire module but not necessarily for each input channel, which may require additional external isolation components in noisy environments.

9. **Limited Software Integration** While the module works well with Rockwell s ecosystem, integrating it with non-Rockwell systems (e.g., third-party SCADA or HMI platforms) may require additional gateways or protocols, adding complexity.

10. **Physical Size and Space Requirements** The block I/O architecture requires physical space for each module, which can be a drawback in applications with tight space constraints. Newer integrated I/O solutions (e.g., CompactLogix with built-in I/O) may offer a more compact footprint.

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The **Allen-Bradley 1791-16AO 16-Input 120V AC Block I/O Module** is a reliable, well-proven choice for applications requiring discrete inputs in a Rockwell Automation environment. Its strengths lie in its durability, compatibility with legacy systems, and ease of installation, making it ideal for industrial settings where reliability and simplicity are prioritized over cutting-edge features.

However, its **legacy status** means it lacks some of the advanced diagnostics, flexibility, and integration options found in newer I/O modules. If your application requires high-speed communication, mixed I/O in a single module, or advanced fault detection, a newer module (e.g., from the 1756 or CompactLogix series) may be a better long-term investment.

For users with existing 1791 systems or those in industries where reliability is paramount and future upgrades are not imminent, this module remains a solid choice. For new projects or applications requiring scalability and advanced features, evaluating newer I/O options may be more beneficial.

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- You are maintaining or expanding an existing Rockwell Automation system that already uses the 1791 series.

- Your application requires 120V AC inputs and does not need advanced diagnostics or high-speed communication.

- You prioritize reliability and simplicity over future-proofing.

- You have space and budget constraints that make newer, more complex I/O systems impractical.

- You are starting a new project and want to leverage the latest features (e.g., Ethernet/IP over TSN, integrated diagnostics, or mixed I/O).

- Your application requires high-density I/O or advanced fault isolation.

- You anticipate future system upgrades or expansions that may not be compatible with legacy I/O.

- You need better integration with non-Rockwell systems or modern SCADA/HMI platforms.

In summary, the 1791-16AO is a **sound choice for legacy systems** but may not be the best long-term investment for new or rapidly evolving automation projects. Always weigh your current needs against future requirements before making a decision.

Details:

Brand:Allen-Bradley Part Number: 1791-16AO: 16-Input, 120V AC Block I/O Module, Comments: Good Part In Condition. KR Automation will not obtain or supply software firmware on your behalf. Some hardware products may contain software and/or firmware and not be legally operated without first obtaining a proper license from the manufacturer.

part #: 179116ao prices

• $339.99-$835.76

specifications sensoindustria:

• brand: Allen-bradley
• mpn: 1791-16ao
• part type: Ac Block Module
• condition: Pre-owned Ser.b Missing Din Clip

offer sensoindustria:

• options: Ship-to-home
• quantity: 1
• sold: 0
• started: March 17, 2026
• availability: In Stock

seller sensoindustria:

• city: Ponca City, Oklahoma
• # reviews: 8469
• rating: 100.0%

general sensoindustria:

• condition: Used
• PLCs HMIs > PLC Peripheral Modules > PLC Input Output Modules

payments sensoindustria:

• other
• wallet: Google-pay
• credit card: Diners-club

returns sensoindustria:

• time: 30 Days
• policy: Returns Accepted
• paid by: Seller
• method: Money back

shipping sensoindustria:

• type: Fixed
• transit: 3-7 Days
• cost: $0.00
• carrier: UPS
• service: Standard, UPS Ground, Overnight
• class: Standard, One-day

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