Product Overview

The Allen-Bradley 1786-FS100 is a 100-meter fiber optic cable assembly used in ControlNet communication networks. It belongs to the 1786-FS short-distance fiber cable family and connects compatible ControlNet fiber repeater modules through a preassembled optical connection.

Unlike conventional coaxial ControlNet trunk cables, the 1786-FS100 transmits communication signals through optical fiber. This makes it particularly useful when network connections must cross electrically noisy areas, connect separate control cabinets, or link automation equipment that is physically separated within an industrial facility.

The cable uses 200-micron HCS (Hard-Clad Silica) fiber and V-pin connectors compatible with the Versalink V-System interface. It is intended for use with the Allen-Bradley 1786-RPFS short-distance fiber repeater.

A typical application involves connecting two ControlNet fiber interfaces across different sections of a production facility. For example, a PLC control cabinet may communicate with a remote fiber repeater through the 1786-FS100, allowing the network to extend beyond the immediate area of the main coaxial trunk.

The 100-meter cable length offers greater routing flexibility than shorter assemblies such as the 1786-FS10 and 1786-FS20. It is suitable for installations where the connected equipment is separated by a longer cable route, without requiring technicians to prepare and terminate a custom fiber cable on site.

The 1786-FS100 is a passive optical transmission component. It does not convert electrical signals, amplify communication signals, or manage network traffic independently. Those functions are handled by the connected ControlNet repeater or communication hardware.

For maintenance engineers, connector cleanliness, cable routing, and minimum bend radius are important considerations. Damage to the fiber or contamination at the optical connection can increase signal loss and interrupt communication between network sections.

Product Features

• 100-Meter Cable Assembly: Provides a longer optical connection for ControlNet installations requiring additional routing distance.
• 200-Micron HCS Fiber: Uses hard-clad silica fiber for short-distance ControlNet optical communication.
• Versalink V-System Connectors: Uses V-pin connector terminations compatible with the designated fiber repeater interfaces.
• 1786-RPFS Compatibility: Intended for use with Allen-Bradley short-distance fiber repeater modules.
• Electromagnetic Interference Immunity: Optical transmission avoids the electrical interference associated with copper communication wiring.
• Preassembled Cable: Reduces the need for field fiber termination when the supplied connector configuration matches the installation.
• Extended Routing Flexibility: Supports connections between control cabinets and network equipment separated by longer distances.
• Passive Communication Medium: Transfers optical signals without requiring an independent power supply.
• Industrial Installation Suitability: Supports fiber connections in automation environments with motors, drives, and electrical switching equipment.
• Reduced Copper Dependence: Allows selected ControlNet network sections to use optical media instead of continuous coaxial connections.

Technical Specifications

Product Working Principle

The 1786-FS100 transfers ControlNet communication signals through an optical fiber connection between compatible fiber interfaces.

In a typical ControlNet installation, the main network may use coaxial trunk cable to connect controllers, communication modules, and network taps. When a section of the network needs to be extended through fiber, a compatible repeater converts the electrical network signals into optical signals.

The 1786-FS100 carries these optical signals through its HCS fiber core. At the receiving end, the connected fiber module converts the optical signals back into electrical communication signals for the next ControlNet network section.

A simplified communication path is:

ControlNet Coaxial Network → 1786-RPA → 1786-RPFS → 1786-FS100 → Remote 1786-RPFS Interface → ControlNet Network

The cable itself does not perform signal conversion. Its function is to maintain the optical transmission path between the connected modules.

The 200-micron HCS fiber construction is matched to the short-distance fiber repeater system. The V-pin connectors establish the optical interface with compatible equipment, while the cable’s optical power budget determines the allowable total signal loss across the fiber connection.

For the 1786-FS100, the specified optical power budget is 4.2 dB. This allowance must account for fiber attenuation, connector losses, and any additional optical connection losses in the installed link.

Cable handling also affects communication performance. Excessive bending, crushing, or pulling can damage the fiber structure and increase optical attenuation. Keeping the connectors clean and maintaining the specified bend radius helps preserve the optical transmission path.

Role in Allen-Bradley ControlNet Network Architecture

The 1786-FS100 functions as the optical transmission link in an Allen-Bradley ControlNet fiber repeater arrangement. It allows compatible fiber modules to exchange communication signals across a distance of up to the cable assembly’s specified length.

In installations using mixed coaxial and fiber media, the coaxial trunk can serve the main network while fiber connections are introduced between selected network sections. This arrangement is useful when equipment is separated by long cable routes or when electrical isolation is required.

A typical arrangement is:

ControlNet Coaxial Trunk → Network Tap → 1786-RPA → 1786-RPFS → 1786-FS100 → Remote Fiber Repeater → ControlNet Network

The 1786-FS100 is particularly relevant when a ControlNet network needs a longer optical connection between repeater modules while retaining the short-distance HCS fiber architecture.

Industrial Applications

The 1786-FS100 is used in industrial facilities where ControlNet communication needs to extend through fiber connections between separated automation areas.

Installation and Maintenance

1. Verify Cable Compatibility: Confirm that the 1786-FS100 is being used with compatible 200-micron HCS fiber interfaces and the appropriate ControlNet repeater hardware.
2. Check Repeater Requirements: Verify that the connected equipment supports the Versalink V-System interface and is compatible with the 1786-RPFS short-distance fiber module.
3. Inspect the Cable Assembly: Examine the cable jacket and both connector ends for cuts, deformation, contamination, or other visible damage.
4. Clean the Connectors: Remove dust and contamination from the optical connector surfaces using suitable fiber cleaning materials before connection.
5. Protect Unused Connectors: Keep protective caps installed whenever the cable is disconnected to prevent dirt from entering the optical interfaces.
6. Plan the Cable Route: Select a route that avoids sharp edges, moving machinery, excessive mechanical stress, and sources of physical damage.
7. Maintain the Bend Radius: Keep the cable bend radius at or above the specified minimum of 25 mm throughout the installation.
8. Control Pulling Force: Avoid exceeding the maximum pulling tension of 490 N when routing the cable through trays, conduits, or cabinet openings.
9. Connect the Fiber Interfaces: Align the V-pin connectors with the corresponding Versalink interfaces and secure the connections according to the equipment requirements.
10. Check Mechanical Support: Provide suitable cable support so that the connector assemblies do not carry the weight of unsupported cable sections.
11. Verify Optical Communication: Restore the network and check the repeater status and communication between the connected ControlNet sections.
12. Document and Store: Record the cable route and connection points, then store the cable with its connector protection in place if it is removed for maintenance.

During troubleshooting, inspect the optical connectors and cable routing before replacing repeater modules. A contaminated connector, damaged fiber, or excessive bend can produce communication problems even when the electronic modules are functioning correctly.

Compatible System Components

Recommended Related Models

Key Advantages

• 100-meter preassembled fiber connection for ControlNet networks.
• 200-micron HCS fiber matched to the short-distance repeater system.
• Versalink V-System connector configuration.
• Compatible with the Allen-Bradley 1786-RPFS fiber repeater.
• Optical transmission avoids electromagnetic interference in copper media.
• Suitable for connections between separated industrial control areas.
• Supports mixed coaxial and fiber ControlNet network architectures.

Technical FAQs

1. Which repeater module should be used with the 1786-FS100?

The 1786-FS100 belongs to the short-distance fiber cable family and is intended for use with the Allen-Bradley 1786-RPFS repeater. The repeater supports the 200-micron HCS fiber system and compatible V-System connections.

2. Can the 1786-FS100 replace the 1786-FS60 in an existing installation?

Both are members of the same short-distance ControlNet fiber cable family and use the same general fiber technology. The primary difference is cable length: the FS100 is 100 meters, while the FS60 is 60 meters. The actual installation must still meet the repeater’s optical power budget and cable-routing requirements.

3. Does the 1786-FS100 provide electrical isolation between ControlNet network sections?

Yes. The optical fiber link does not carry electrical current between its two ends. This helps isolate the connected network sections from electrical interference and unwanted conductive paths. The repeater hardware is responsible for converting the electrical network signals into optical signals and back again.

4. What should be checked if communication fails after installing the 1786-FS100?

Start by checking whether both V-pin connectors are properly seated and clean. Then inspect the cable for kinks, excessive bending, or physical damage. If the cable and connectors are in good condition, verify the repeater power supply, module status, and total optical link loss against the specified 4.2 dB power budget.