Allen-Bradley 1769-OF8C CompactLogix 8-Channel Analog Output Module

Product Overview

The Allen-Bradley 1769-OF8C is a high-density Compact I/O™ analog output module designed for use with CompactLogix™ controllers or as distributed I/O in a 1769-based assembly. It features eight (8) high-resolution current outputs, capable of providing precise 0-20 mA or 4-20 mA signals to field devices such as valve actuators, motor speed controllers, and recorders. Its 16-bit resolution and fast conversion rate make it an ideal choice for complex process control applications requiring high accuracy and reliability.

Technical Configuration

• Manufacturer: Allen-Bradley / Rockwell Automation
• Product Line: CompactLogix / 1769 Compact I/O
• Catalog Number: 1769-OF8C
• Output Type: Analog Current (8 Channels)
• Signal Range: 0 to 20 mA and 4 to 20 mA
• Digital Resolution: 16-bit (unipolar)
• Power Requirement: 24V DC External Power Supply

Technical Specifications

Installation & Wiring

1. Signal Integrity: To ensure the highest accuracy for the 1769-OF8C, use shielded twisted-pair cable for all analog signals. Keep analog wiring away from high-noise power lines and ensure the shield is grounded at only one end (typically at the I/O chassis) to prevent ground loops.

2. Module Placement: The 1769-OF8C has a specific power supply distance rating. Ensure the module is placed within the allowed distance from the system power supply to maintain stable 24V DC levels and prevent signal fluctuation.

3. Protection Features: This module includes built-in open and short-circuit protection. If a channel exceeds 21 mA or detects an open loop, the module's diagnostic bits will trigger, allowing the controller to execute safe-state logic or notify maintenance personnel immediately.

Engineering Advantages

The 1769-OF8C provides an excellent balance of channel density and precision. With eight individual current loops in a single module width, it saves significant DIN rail space compared to lower-density modules. Its extended operating temperature range (-20°C to +60°C) allows for deployment in diverse environments, while the 16-bit resolution ensures that even the most minute control adjustments are executed with absolute fidelity.

Technical FAQs

Q1: Does this module support voltage outputs?
A1: No, the 1769-OF8C is specifically designed for current outputs (0-20mA/4-20mA). For voltage outputs, consider the 1769-OF8V.

Q2: Is an external power supply required for the loops?
A2: Yes, the 1769-OF8C requires a user-supplied 24V DC power source to power the analog output circuitry and the current loops.

Q3: How fast can the module update all 8 channels?
A3: The module features a fast conversion rate of 5 ms for all eight channels simultaneously, providing near-real-time response for process loops.