Product Overview

The Allen-Bradley 1756-OB16IEF is a fast isolated DC output module for ControlLogix. This module provides 16 individually isolated digital outputs. It features Pulse Width Modulation (PWM) capability for precise control. The Allen-Bradley 1756-OB16IEF includes electronic fusing and per-point protection. Users trust this module for high-speed peer-to-peer control applications.

Technical Specifications

The 1756-OB16IEF delivers fast response with comprehensive protection features. Below are the complete technical details.

General Specifications

• Manufacturer: Rockwell Automation for industrial control reliability.

• Brand: Allen-Bradley for ControlLogix compatibility.

• Part Number: 1756-OB16IEF for precise identification.

• Series: ControlLogix family.

• Module Type: DC Output Module (Fast Isolated).

• Circuit Type: DC sink/source.

• Enclosure: None (open-style).

• UPC: 10885630081783 for universal product identification.

Output Specifications

• Number of Outputs: 16 individually isolated outputs.

• Operating Voltage Range: 10 to 30 Volts DC.

• Input Voltage Range: 10 to 30 Volts.

• Output Type: Fast peer-to-peer with PWM capability.

• Response Time: Less than 25 µs for system transition.

• Minimum Load Current: 1 mA per point.

• Surge Current: 4 A for 10 ms per point, repeatable every 2 s.

• Maximum Off-State Leakage: < 0.1 mA per point.

• Maximum On-State Voltage Drop: 0.2V DC at 1A, 0.4V DC at 2A.

Current Ratings (Temperature Dependent)

• Per Point at 30°C: 2 Amps maximum.

• Per Point at 60°C: 1 Amp maximum.

• Per Module at 30°C: 8 Amps maximum (2A per channel).

• Per Module at 60°C: 4 Amps maximum (1A per channel).

• Maximum at 45°C: 2A per point (max 4 channels), 8A per module.

• Pilot Rating: 4 A inrush capability.

Power Specifications

• Backplane Current at 5 Volts: 350 milliamps (320 mA typical).

• Backplane Current at 24 Volts: 3 milliamps.

• Total Backplane Power: 1.7 W.

• Power Dissipation (Max): 3.6 Watts at 60°C.

• Isolation Voltage: 50 Volts Continuous (250V continuous noted in description).

• Tested Isolation: High voltage protection.

Pulse Width Modulation (PWM) Specifications

• PWM Cycle Time: 1 ms minimum to 1 hour maximum.

• PWM On-Time: 200 µs minimum to 1 hour maximum.

• PWM On-Time Accuracy: ±20 µs for precise timing.

• Application: Precise output control for proportional applications.

Protection Features

• Electronic Fusing: Per-point electronically fused.

• Per-Point Protection: Individually isolated outputs.

• Fault Reporting: Diagnostic information latch.

• Configurable Output States: Hold, Last State, On, or Off.

• Fault Mode Durations: 1, 2, 5, 10 seconds, or Forever.

• Final State After Fault: Off or On configurable.

• Default State: Off for all settings except Forever.

• Diagnostic Information Latch: Captures fault data.

CIP Sync Features

• CIP Sync Slave-Only: Requires master clock on network.

• Timestamps and Scheduling: CIP Sync for precise timing.

• Peer Control: Fast peer-to-peer communication.

Additional Features

• Configurable Point-Level Output States: Per-channel configuration.

• Output Data Echo: Feedback of output status.

• Multiple Output Point Densities: Flexible system design.

• Status Indicators: Diagnostic and I/O status LEDs.

Compatible Removable Terminal Blocks (RTB)

• 1756-TBCH: Compatible RTB housing.

• 1756-TBS6H: Compatible RTB housing.

• Requirement: RTB needed before chassis installation.

Installation Guide

Follow these steps to install the Allen-Bradley 1756-OB16IEF correctly.

1. Power Down the Chassis: Turn off all power to the ControlLogix rack.

2. Select Compatible RTB: Choose 1756-TBCH or 1756-TBS6H.

3. Wire the RTB: Connect field devices to the removable terminal block.

4. Install RTB on Module: Attach the wired RTB to the 1756-OB16IEF.

5. Locate an Available Slot: Find any empty slot in the ControlLogix chassis.

6. Insert the Module: Slide the 1756-OB16IEF into the slot carefully.

7. Secure the Module: Lock using the retaining clips at top and bottom.

8. Verify Power Supply: Ensure chassis provides 350 mA at 5V DC.

9. Apply Power: Turn on the chassis power supply.

10. Configure in Studio 5000: Add module to I/O configuration.

11. Set Fault Mode: Choose Hold, Last State, On, or Off per output.

12. Select Fault Duration: Configure 1, 2, 5, 10 seconds, or Forever.

13. Configure PWM Parameters: Set cycle time and on-time as needed.

14. Set Up CIP Sync: Connect master clock device for timestamping.

15. Test Outputs: Verify response time under 25 µs.

16. Monitor Diagnostics: Check LED indicators for I/O status.

Installation Notes

• The module responds to commands in less than 25 µs.

• Electronic fusing protects each output point individually.

• PWM on-time accuracy is ±20 µs for precision applications.

• The module requires a master clock device for CIP Sync.

• Default fault state is Off except when Fault Mode is Forever.

Packaging List

This unit ships as a new and original product.

• Allen-Bradley 1756-OB16IEF ControlLogix Fast Isolated Output Module

• RTB not included (requires 1756-TBCH or 1756-TBS6H)

• Product data sheet with PWM configuration guide

• Anti-static factory packaging box

Frequently Asked Questions (FAQ)

1. What is the response time of the 1756-OB16IEF output module?
The Allen-Bradley 1756-OB16IEF responds to system transition commands in less than 25 µs. This makes it suitable for high-speed control applications.

2. What PWM features does this output module support?
The 1756-OB16IEF supports PWM cycle time from 1 ms to 1 hour. PWM on-time ranges from 200 µs to 1 hour with ±20 µs accuracy.

3. What are the available fault mode settings on this module?
The 1756-OB16IEF offers fault mode settings of Hold, Last State, On, or Off. Fault durations are 1, 2, 5, 10 seconds, or Forever.

4. Which removable terminal blocks work with the 1756-OB16IEF?
The Allen-Bradley 1756-OB16IEF works with 1756-TBCH and 1756-TBS6H removable terminal blocks. You must install the RTB before chassis mounting.

5. What is the current rating per output at different temperatures?
The 1756-OB16IEF delivers 2A per point at 30°C and 1A per point at 60°C. The module supports 8A total at 30°C and 4A at 60°C.