Product Overview
ControlNet networks in oil, gas and process plants often stretch far beyond the reach of a single coax segment. The Allen-Bradley 1786-RPFM solves that problem as a medium-distance fiber optic repeater in the Bulletin 1786 ControlNet family. It regenerates the network signal across two fiber channels, extending a link up to 3000 m between two ControlNet products while adding noise immunity and ground isolation.
One important distinction: this module is not a ring repeater. Redundant ring topologies require the 1786-RPFRL or 1786-RPFRXL. The 1786-RPFM is the point-to-point medium-distance fiber module, and it mounts on DIN rail with a 24V DC supply. Rockwell lists it as discontinued on 2025-12-30 with an Engineering Replacement path, so buyers should confirm current lifecycle status and availability with Oil AutoTech before ordering.
Technical Specifications
| Specification | Value |
|---|---|
| Manufacturer | Allen-Bradley (Rockwell Automation) |
| Series | ControlNet / Bulletin 1786 |
| Product Type | Fiber Optic Repeater (Medium-distance) |
| Fiber Channels | Dual (CH1/CH2) |
| Network Speed | 5 Mbps |
| Fiber Type | 62.5/125 um multimode, ST connectors, 1300 nm |
| Max Distance | Up to 3000 m |
| Supply Voltage | 24V DC |
| Current / Power | 400 mA @ 5V, 2W max |
| Adapter Support | Up to 4 per 1786-RPA/B adapter |
| Mounting | DIN rail |
Cost and Efficiency Implications
Every specification on this module maps to a cost line. The 3000 m reach means fewer repeaters per run, which lowers hardware count, cabinet space and installation labor. Dual fiber channels give you a spare path or a second segment without buying another module. Multimode 62.5/125 um fiber with ST connectors is widely stocked and inexpensive to terminate compared with single-mode alternatives, keeping cable and contractor costs predictable.
The 24V DC input at 2W max keeps power draw low, so existing DC supplies and panel wiring usually handle it without upgrades. DIN rail mounting reduces enclosure footprint. For plants running ControlNet at 5 Mbps, the 1786-RPFM protects the installed network investment by extending its physical reach rather than forcing a full network migration.
Integration and Selection Notes
This repeater works inside ControlNet architectures that use quad-shielded RG-6 coax (75 ohm) with BNC connectors on the trunk side, and fiber on the extended side. ControlNet supports redundant media (Trunk A/Trunk B) and up to 99 nodes per network, with ambient operating temperature up to 60 C and storage from -40 to 85 C.
Before you buy, verify three things: the link distance, the fiber type and connector, and whether your topology needs a ring repeater instead. If your design calls for a redundant ring, the 1786-RPFRL or 1786-RPFRXL is the correct part, not this module. Oil AutoTech offers hands-on technical selection help and fast dispatch, worldwide, so you can match the right repeater to your ControlNet segment quickly.
Maintenance and Reliability
Fiber links are less prone to electrical noise than long coax runs, which reduces intermittent faults and unplanned downtime. Inspect connectors and fiber routing periodically, keep the DIN rail and ventilation clear, and follow the manufacturer’s documentation for all service work. Because the module is discontinued, keeping a ready-to-ship spare on the shelf is a practical way to avoid production losses if a link fails.
FAQs
Is the 1786-RPFM a ring repeater?
No. It is a medium-distance fiber repeater with two fiber channels. Ring or redundant topologies require the 1786-RPFRL or 1786-RPFRXL.
What is the maximum distance for this module?
Up to 3000 m over 62.5/125 um multimode fiber with ST connectors at 1300 nm.
What power does the 1786-RPFM need?
It operates on 24V DC and draws 400 mA @ 5V, with 2W max power.
Is the 1786-RPFM still available?
Rockwell lists it as discontinued on 2025-12-30 with an Engineering Replacement. Contact Oil AutoTech today for pricing and availability.
