Product Overview

The Allen-Bradley 1769-OF8C is an analog output module from the CompactLogix series. It provides eight current output channels for precise control. You can configure each channel for 0-20 mA or 4-20 mA. The 1769-OF8C works with CompactLogix 1769, 1768, and MicroLogix 1500 controllers. This module drives valves, VFDs, positioners, and panel meters. It offers high reliability for industrial automation loops.

Technical Specifications

Output Characteristics

– Number of Outputs: Eight (8) single-ended current outputs
– Output Current Ranges: 0-20 mA or 4-20 mA (configurable)
– Full Scale Analog Range: 0-21 mA or 3.2-21 mA
– Resolution: 16-bit unipolar
– Converter Type: Delta Sigma DAC
– Output Impedance: >1 Ohm

Performance and Accuracy

– Overall Accuracy: ±0.35% full scale at 25°C
– Conversion Rate (all channels): 5 ms maximum
– Step Response to 63%: <2.9 ms
– Resolution Details: 15.59 bits (4-20 mA) / 15.91 bits (0-20 mA)
– Microamp per Bit: 0.323 µA/bit

Electrical and Protection

– Maximum Short-Circuit Current: 21 mA
– Short-Circuit Protection: Yes
– Open Wire Detection: Yes (5 ms detection time)
– Overvoltage Protection: Yes
– Resistive Load (with wire): 0 to 500 Ohms
– Maximum Inductive Load: 0.1 mH

Power and Heat Dissipation

– Current Draw at 5V DC: 145 mA
– Current Draw at 24V DC: 185 mA
– Heat Dissipation: 2.69 Watts
– External Power Supply Required: 24V DC

Environmental and Physical

– Temperature Range: 0°C to 60°C (32°F to 140°F)
– Enclosure: None (indoor use only)
– Wire Type: Copper 90°C
– Solid Wire Size: 22 to 14 AWG
– Stranded Wire Size: 22 to 16 AWG
– Replacement Door Part: 1769-RD
– Dimensions: 4.65 x 1.38 x 3.43 inches
– No field calibration required: Yes

Installation Guide

Follow these steps to install the 1769-OF8C correctly.
1. Remove power from the CompactLogix system before starting.
2. Slide the module into an empty 1769 I/O slot.
3. Press the interlocking side tabs firmly to lock it.
4. Route wires from beneath the module to the terminal block.
5. Use copper wire of 22-14 AWG (solid) or 22-16 AWG (stranded).
6. Connect the external 24V DC power supply to the module.
7. Wire each output channel to the load (0-500 Ohms).
8. Close the finger-safe door after wiring is complete.
9. Restore power and check the green OK LED indicator.
10. Configure output ranges (0-20 mA or 4-20 mA) in your controller.

Package Contents

– One Allen-Bradley 1769-OF8C analog output module
– One removable terminal block (finger-safe, pre-installed)
– One installation instructions sheet
– Replacement door kit (1769-RD) is sold separately
– No communication cable included

Frequently Asked Questions (FAQ)

1. Which controllers work with the 1769-OF8C?

The 1769-OF8C works with CompactLogix 1769, 1768, and MicroLogix 1500 controllers. It cannot be used with other platforms.

2. Can I mix voltage and current outputs on this module?

No, the 1769-OF8C provides current outputs only. Use the 1769-OF8V for voltage output applications.

3. What happens if a field device fails open circuit?

The module detects open-wire conditions within 5 milliseconds. The status LED and bit reporting will alert you.

4. Is field calibration required for the 1769-OF8C?

No, the 1769-OF8C does not need field calibration. Factory calibration covers the full temperature range.

5. Why is my module getting warm during operation?

The 1769-OF8C dissipates 2.69 Watts of heat normally. Ensure proper ventilation around the I/O rack.

Compatibility and Applications

The Allen-Bradley 1769-OF8C integrates seamlessly into PID control loops. It drives modulating control valves, variable frequency drives, and positioners. The module also sends signals to panel meters, data loggers, and signal splitters. Each of the eight channels provides isolated current output up to 21 mA. The green OK LED shows normal operation at a glance. Use this module for precise analog control in factory automation.