Product Description
The Allen-Bradley 1788-FBJB4R is a Foundation Fieldbus junction box that connects up to four field devices to a linking device (like the 1788-EN2FFR for Ethernet or the 1788-CN2FFR for ControlNet) via H1 media. It features dual trunk connectors for redundancy, monitors and limits port current during faults, and is certified to CE, KC RCM, and c-UR-us standards. It consumes 40mA at 24V DC, operates on 12-32V DC (0.5A), and provides trunk output of 12-32V DC (0.36A) and drop output of 12-32V DC (40mA). Use 24-18 AWG stranded or solid copper wire (rated for 180F minimum) for power connections. Optimal performance and storage require an ambient temperature of 32-140F and non-condensing relative humidity of 5-95%.
Is Your Device Showing These Signs?
The Allen Bradley 1788-FBJB4R EtherNet/IP bridge commonly experiences issues related to corrupted firmware, resulting in communication failures and network disconnections. Resolve these problems by performing a firmware upgrade or re-flashing the device. Configuration errors, such as incorrect IP address assignments or subnet mask settings, prevent proper network integration. Verify and correct these settings via the configuration utility. Hardware failures, including damaged connectors or internal component malfunctions, cause intermittent connectivity or complete device inoperability. Replace the damaged components or the entire bridge to restore functionality.
Technical specifications
The Allen-Bradley 1788-FBJB4R is a Foundation Fieldbus junction box that connects up to four field devices to a linking device using H1 media. It offers redundancy with dual trunk connectors, monitors and limits port current during faults, and is certified to various standards. It requires specific power input and wiring, and operates within defined temperature and humidity ranges.
Our Repair Process for the
1788-FBJB4R
Our repair process for the Allen Bradley 1788-FBJB4R EtherNet/IP bridge begins with a thorough assessment to identify the root cause of the issue. If corrupted firmware is suspected, a firmware upgrade or re-flashing of the device is performed immediately. Configuration settings, including IP address and subnet mask, are verified and corrected using the configuration utility. In cases of hardware failure, damaged connectors or malfunctioning internal components are replaced; complete bridge replacement occurs if necessary to ensure full functionality. This process guarantees restoration of communication and network connectivity.
Your Guarantee: Warranty & Lifetime Support
Your satisfaction is our top priority, and we confidently stand behind the quality of our repairs. That's why every repair service is covered by our comprehensive 24-month warranty. Furthermore, we offer lifetime phone support – if you have questions or need assistance related to our repair down the road, we're here to help. Our service commitment is straightforward: we guarantee our work, and if you're not satisfied, we will make it right. Learn More about our Repair process.
Comprehensive Repairs You Can Depend On
We take immense pride in the quality and reliability of our work. Our process goes beyond simply fixing the immediate problem. We perform a comprehensive inspection of your main board (or other equipment) and proactively replace components known to be failure-prone or showing signs of potential future failure. Before any item is returned, it undergoes rigorous functional testing to ensure it meets performance specifications and operates flawlessly. Visit our main Repair Services page to learn more.
Save Significantly
Our primary goal is to save you hundreds, or even thousands, of dollars compared to the cost of new equipment replacement. By repairing existing components, we provide an economical solution that is also eco-friendly. At Roc Industrial, our commitment to integrity and community drives our consistent growth and ensures you receive a reliable, cost-effective solution.


Please Note: Roc Industrial operates as an independent service provider and is not an authorized distributor for the manufacturers or brands mentioned. Consequently, the original manufacturer's warranty is not applicable to items repaired or sold by us. Roc Industrial provides its own 2-year warranty on all repair services performed.
Buying Options
To receive a quote within 2 hours, please provide us with the details of your requirements. Our team will promptly review your request and send you a custom offer.
Ships from Rochester, NY