1771-OP | Allen Bradley | PLC 5 Protected AC Output Module

Product Overview

The Allen Bradley 1771-OP serves as a specialized, protected AC output interface for the PLC-5 Universal I/O chassis. This module provides 4 high-integrity output channels designed to drive low-power 120V AC loads while providing an auxiliary +5V DC output for peripheral logic or signaling. We offer this unit as 100% Brand New, original factory stock, ensuring the protective switching characteristics and backplane synchronization required for specialized automation sequences.

Technical Specifications

The 1771-OP manages precise AC power delivery with integrated electronic protection across all four channels.

Engineering Advantages

• Integrated Circuit Protection: The 1771-OP features internal protection mechanisms that shield the module from common electrical faults. This "Protected" designation ensures that downstream anomalies do not compromise the integrity of the PLC backplane, maintaining system uptime in unpredictable electrical environments.

• Dual-Voltage Capability: This module provides both 120V AC switching and a +5V DC output. This combination eliminates the need for auxiliary power supplies when interfacing with low-voltage TTL logic, specialized sensors, or small signal indicators located near the output terminations.

• Optimized for Low-Power Actuators: While high-density modules often struggle with minimum leakage current, the 1771-OP excels at controlling smaller AC loads up to 350 mA. It provides a stable "Off" state for sensitive solenoids and relays that might otherwise stay energized due to leakage in high-amperage cards.

• Wide Frequency Tolerance: The module operates across a 47 to 63 Hz range. This flexibility allows the 1771-OP to function reliably on both 50 Hz and 60 Hz power grids, making it an ideal choice for global industrial machinery installations and varying facility power standards.

FAQs

• What does the "Protected" status signify for the 1771-OP?

  The 1771-OP contains electronic protection circuitry designed to mitigate the effects of overcurrent and certain surge conditions. This feature prevents localized field-side faults from causing catastrophic failure to the module or the host PLC-5 processor.

• Can I use the 1771-OP to drive a 2 Amp motor starter?

  No. Each output on the 1771-OP supports a maximum of 350 mA. For loads exceeding this limit, such as large NEMA-rated motor starters, you must use an interposing relay or switch to a high-current module like the 1771-OAD.

• Is this module compatible with all PLC-5 racks?

  The 1771-OP fits into any standard 1771 Universal I/O chassis. It communicates through the backplane with PLC-5, SLC 500 (via 1747-ASB), or ControlLogix (via 1771-remote I/O adapters) systems.

• How do I utilize the +5V DC output?

  The +5V DC output provides a small amount of logic-level power for external devices. Engineers typically use this for pull-up resistors, signal conditioning circuits, or low-power LED indicators that require a steady DC reference alongside AC control signals.