Product Overview

The Allen-Bradley 1794-ACNR15 is a high-performance communication adapter. It belongs to the trusted Flex I/O product family. This module builds a redundant ControlNet data highway. It automatically switches to the second trunk if one fails. This design maximizes system uptime for critical processes.

Technical Specifications

The 1794-ACNR15 operates with a nominal voltage of 24V DC. Its input voltage range is 19.2 to 31.2V DC. The module draws a maximum current of 400 mA from the external supply.

Communication features include:

• Two ControlNet BNC ports for redundancy

• Fixed data transfer speed of 5 Mbps

• Supports ControlNet Protocol V 1.25

• Connects to ControlNet trunk lines directly

Power and thermal data:

• Maximum power dissipation: 3.4W at 19.2V DC

• Thermal dissipation: 15.7 BTU/hr

• FlexBus output current: 640 mA max

• Inrush current: 23A for 2ms

Environmental limits:

• Operating temperature: -20 to 55 °C (-4 to 131 °F)

• Surrounding air temperature: 55 °C (131 °F)

• Relative humidity: 5-95% non-condensing

• Vibration resistance: 5g at 10 to 500 Hz (IEC 60068-2-6)

• Operating shock: 30g (IEC 60068-2-27)

Isolation and protection:

• Isolation voltage: 850V DC

• The 1794-ACNR15 has a T4 temperature code

• It meets IEC 60068-2-6 and IEC 60068-2-27 standards

LED Indicators and Diagnostics

The front panel shows three LED indicators. Comm A and Comm B show each ControlNet port status. The I/O status LED indicates connected Flex I/O module health. These lights help operators find faults quickly. They reduce downtime during troubleshooting.

Installation Guide

Mount the 1794-ACNR15 on a standard DIN rail. You can also use wall mounting with proper brackets. Tighten mounting screws to 7 pound-inches torque. Use copper wire sized 0.33 to 2.5 mm² (22-12 AWG). The wire insulation must rate for 75 °C or higher. Maximum insulation thickness is 1.2 mm (3/64 inch). For double wire connections, use 0.33 to 1.3 mm² (22-16 AWG) wire. Do not mix solid and stranded wires in the same terminal.

Keep the adapter away from high-voltage cables. Leave space for air circulation around the module. The 1794-ACNR15 measures 87 x 94 x 69 mm. Its lightweight design (220g) allows easy handling.

Compatibility and System Integration

This Allen-Bradley 1794-ACNR15 works with any Flex I/O module. You can mix digital, analog, and specialty I/O types. The adapter supports a maximum of eight I/O modules per node. It connects to a ControlNet network using BNC connectors. Use 3.31 mm² (12 AWG) stranded cable for trunk lines. The 1794-ACNR15 automatically handles data routing between two ControlNet trunks.

Package Contents

• One Allen-Bradley 1794-ACNR15 Redundant ControlNet Adapter

• One DIN rail mounting foot (pre-installed)

• One removable power terminal block

• Product label with catalog number

• Installation instructions quick start guide

Frequently Asked Questions (FAQ)

1. How many Flex I/O modules can the 1794-ACNR15 support?
The 1794-ACNR15 supports up to eight Flex I/O modules. You can mix any type within this limit.

2. Does the 1794-ACNR15 work without a redundant ControlNet trunk?
Yes, the 1794-ACNR15 works with a single ControlNet trunk. The second port simply stays unused.

3. What happens if one ControlNet cable fails?
The 1794-ACNR15 automatically routes all data to the working trunk. Your I/O communication continues without interruption.

4. Can I use the 1794-ACNR15 in a -20°C environment?
Yes, the 1794-ACNR15 operates from -20°C to 55°C. It suits cold storage or outdoor enclosures with heating.

5. What is the maximum FlexBus current output of this adapter?
The 1794-ACNR15 provides 640 mA to connected Flex I/O modules. This power comes from your external 24V supply.