1756-OF6CI Analog Output Module | Allen-Bradley ControlLogix

Overview

The 1756-OF6CI is a six-channel isolated analog output module developed for the Allen-Bradley ControlLogix platform. Each channel operates independently, delivering precise and stable analog current output signals for high-performance industrial control systems. With 13-bit resolution, temperature-compensated accuracy, and wide drive capability, this module provides reliable performance in complex automation and process control applications.

Technical Specifications

• Manufacturer: Allen-Bradley

• Model / Part Number: 1756-OF6CI

• Product Type: Isolated Analog Output Module

• Series: ControlLogix

Outputs

• Number of Channels: 6 individually isolated outputs

• Output Range: 0…21 mA

• Resolution: 13 bits (2.7 μA per bit across 21 mA)

• Drive Capability: 0…1000 Ω load resistance

Current Draw

• @ 5.1V DC:

• 250 mA for 0…550 Ω loads (OUTs and RTNs termination)

• 250 mA for 551…1000 Ω loads (OUTs and ALTs termination)

• @ 24V DC:

• 225 mA for 0…550 Ω loads

• 300 mA for 551…1000 Ω loads

Power and Dissipation

• Total Backplane Power: 6.7 W (0…550 Ω), 8.5 W (551…1000 Ω)

• Power Dissipation (Max): 5.5 W (0…550 Ω), 6.1 W (551…1000 Ω)

• Thermal Dissipation: 18.76 BTU/hr (0…550 Ω), 20.80 BTU/hr (551…1000 Ω)

Protection & Isolation

• Overvoltage Protection: 24V DC

• Short Circuit Protection: Electronically limited to ≤21 mA

• Open Circuit Detection: None

• Isolation Voltage: 250V continuous (basic insulation, output-to-backplane, channel-to-channel)

• Dielectric Test: 1350V AC for 2 seconds

Performance Characteristics

• Settling Time: <2 ms to 95% of final value (resistive loads)

• Calibrated Accuracy (@ 25°C): ±0.1% of range (4…21 mA)

• Calibration Interval: 6 months typical

• Offset Drift: 1 μA/°C

• Gain Drift (Nominal): 60 ppm/°C

• Gain Drift (Max): 100 ppm/°C

• Module Error: 0.6% of range

• Module Scan Time:

• Floating Point: 25 ms

• Integer: 10 ms

Data and Conversion

• Data Format: Integer (left-justified, 2’s complement), IEEE 32-bit floating point

• Conversion Method: R-Ladder DAC, monotonic with no missing codes

Mechanical & Configuration

• Module Keying: Electronic, software-configurable

• Compatible Terminal Blocks: 1756-TBNH, 1756-TBSH

• RTB Keying: User-defined mechanical

• Slot Width: 1

• Wire Category: 2

Environmental Specifications

• Temperature Rating:

• North American: T4A

• IEC: T4

• Enclosure Type: Open-style (no housing)

Application Notes

The 1756-OF6CI module is ideal for process control systems, analog current loop control, and equipment requiring isolated signal outputs. Its fast settling time and high accuracy make it particularly suited for closed-loop control and precision instrumentation in manufacturing, energy, and process industries.

FAQ

Q: How many isolated channels does the 1756-OF6CI provide?
A: It provides six individually isolated analog output channels.

Q: What is the module’s maximum load resistance?
A: The output can drive loads up to 1000 Ω.

Q: How often should the module be calibrated?
A: A 6-month calibration interval is recommended for optimal accuracy.

Q: Is short circuit protection included?
A: Yes, each output is electronically current-limited to 21 mA or less.