Is Your Control System Vulnerable to Output Failures?
Unexpected output module failures can halt production and increase maintenance costs. The Allen-Bradley 1794-OB8EP addresses this challenge directly with integrated electronic fuse protection. This Flex I/O digital DC output module delivers reliable performance for demanding industrial applications.
What Is the 1794-OB8EP?
The Allen-Bradley 1794-OB8EP is an 8-channel sourcing current output module from the Flex I/O family. It operates with a 24V DC nominal on-state voltage and provides up to 2A per output. The module’s electronic fuse (EP) feature disconnects the output if a fault occurs, protecting your system from damage.
Key Technical Specifications
| Specification | Value |
|---|---|
| Outputs | 8 Sourcing Current |
| On-state Voltage nom. | 24V DC |
| Output Current Rating | 2A max. per Output |
| On-state Voltage Drop max. | 0.2V DC |
| Off-state Leakage Current max. | 0.5mA |
| Isolation Voltage | 50V Continuous |
| Flexbus Current | 73mA @ 5V DC |
| Power Dissipation | 5.5W @ 31.2V DC max. |
| Thermal Dissipation | 18.8 BTU/hr. @ 31.2V DC max. |
These specifications ensure efficient power delivery and minimal signal loss. The low on-state voltage drop of 0.2V DC maximizes energy efficiency, while the 0.5mA off-state leakage current prevents false triggering of connected devices.
Why Choose the 1794-OB8EP for Your Application?
Electronic Fuse Protection
The integrated electronic fuse disconnects faulty outputs automatically. This reduces downtime and prevents damage to other system components. Unlike traditional fuses, the electronic fuse resets after the fault clears, eliminating the need for replacement parts.
Hot-Swappable Design
You can remove or insert the module under power without direct wiring. This saves time during maintenance and eliminates system restart inefficiencies. The module connects to field devices through the terminal bus, simplifying installation.
Wide Compatibility
The 1794-OB8EP works with multiple terminal base units, including 1794-TB2, 1794-TB3, 1794-TB3S, 1794-TBN, and 1794-TBKD. It supports various communication protocols such as ControlNet, DeviceNet, EtherNet/IP, and Universal Remote I/O.
Installation and Setup
Mount the module on a DIN rail by snapping it into place. Ensure the external power supply provides 19.2-31.2V DC with 5% AC ripple and 20-35mA current. The module features 16 yellow LED status indicators for easy monitoring of each channel’s input device and output signal.
Maintenance and Reliability
Regularly inspect connections and verify LED indicators for proper operation. The electronic fuse eliminates periodic fuse replacements, reducing long-term maintenance costs. For extreme environments, XT versions of standard modules are available.
Frequently Asked Questions
What makes the 1794-OB8EP different from standard output modules?
The 1794-OB8EP includes an electronic fuse that automatically disconnects faulty outputs, protecting your system without requiring manual fuse replacement.
Can I replace the module while the system is running?
Yes, the module supports hot-swapping. You can remove or insert it under power since it has no direct wiring.
What communication protocols does the 1794-OB8EP support?
It supports ControlNet, DeviceNet, EtherNet/IP, and Universal Remote I/O.
Which terminal base units are compatible?
Compatible terminal bases include 1794-TB2, 1794-TB3, 1794-TB3S, 1794-TBN, and 1794-TBKD.
How many outputs does the module provide?
The 1794-OB8EP offers 8 sourcing current outputs with 2A maximum per output.
