Allen-Bradley 1794-OB8 Flex I/O Digital DC Output Module

Product Overview

The 1794-OB8 is a Flex I/O digital DC output module by Allen-Bradley. It belongs to the 1794 series. This module has 8 sourcing outputs. The outputs are not isolated. The module is rated for hazardous locations in Europe and North America. The outputs are not fused at the factory. You can fuse them externally. The module uses 24V DC nominal on-state voltage. Each channel can carry up to 500mA. The on-state voltage drop is 0.5V DC maximum. The off-state leakage current is 0.5mA maximum. The isolation voltage is 50V continuous. The FlexBus current draw is 60mA at 5V DC. The power dissipation is 3.3W at 31.2V DC maximum. Thermal dissipation is 11.2 BTU/hr. The module fits inside the terminal bus. It connects field devices and the I/O bus. You can insert or remove modules under power. This saves time and avoids system restart.

Application Scenarios

This module works in industrial automation. It controls DC loads like solenoids and relays. It suits manufacturing lines and process control. The hazardous location ratings allow use in explosive environments. The module works with ControlNet, DeviceNet, EtherNet/IP, and Universal Remote I/O. The XT versions operate in extreme conditions. This reduces panel and maintenance costs.

Technical Specifications

• Manufacturer: Rockwell Automation
• Brand: Allen-Bradley
• Part Number: 1794-OB8
• Product Type: Flex I/O Digital DC Output Module
• Outputs: 8 Sourcing
• On-state Voltage: 24V DC nominal
• Output Current Rating: 4A
• On-state Current: 500mA per channel
• On-state Voltage Drop: 0.5V DC max
• Off-state Leakage Current: 0.5mA max
• Isolation Voltage: 50V Continuous
• Flexbus Current: 60mA @ 5V DC
• Power Dissipation: 3.3W @ 31.2V DC max
• Thermal Dissipation: 11.2 BTU/hr max
• Operating Temperature: 0 to 55°C
• Relative Humidity: 5-95% noncondensing
• Terminal Bases: 1794-TB3, 1794-TB3S, 1794-TBKD
• External Power Supply: 10-31.2V DC, 10-35mA
• LED Indicators: 16 yellow LEDs per channel
• Communication Options: ControlNet, DeviceNet, EtherNet/IP, Universal Remote I/O

Installation & Maintenance Guide

Install the module on a DIN rail. Snap it onto the rail. Use a compatible terminal base unit. Connect field wiring to the terminal base. The module does not need direct wiring. Remove or insert it under power. Ensure proper power supply voltage. Do not exceed maximum limits. Keep the module within operating temperature. Avoid condensation and dust.

Packing List

One 1794-OB8 Flex I/O Digital DC Output Module. One installation manual. Shipping is via Fedex, UPS, or DHL.