Description
Product Introduction
The Honeywell 8937-HN (manufactured in partnership with Eaton MTL) is a industrial-grade fiber optic extender module designed for Experion PKS Series 8 and Series C process control architectures. It converts electrical copper I/O link signals from Honeywell C300 controllers into optical signals, allowing control links to span long distances between central control equipment rooms and remote field enclosures.
Built to maintain full DCS redundancy, the 8937-HN integrates dual Combo Cable interfaces that support primary and secondary I/O channels simultaneously. By replacing copper runs with glass fiber, the module provides complete electrical isolation, eliminating ground potential issues and protecting control signals from high-voltage EMI in harsh plant environments.
Key Technical Specifications
| Parameter | Specification |
| Manufacturer | Honeywell / Eaton MTL Instruments |
| Part Number | 8937-HN |
| System Compatibility | Honeywell Experion PKS Series 8 / Series C / MTL8000 |
| Interface Connections | 2x Combo Cable Interfaces (Dual Redundant I/O Links) |
| Signal Function | Optical conversion and extension of C300 I/O bus signals |
| Transmission Media | Multimode / Single-mode Fiber (System dependent) |
| Operating Voltage | 12 to 36 VDC via carrier bus |
| Operating Temperature | -40°C to +85°C |
| Mounting | Carrier-Mounted / DIN-Rail Assembly |
| Enclosure Rating | Cabinet-mounted, Industrial Hazardous Area Capable |
8937-HN
8937-HN
Application Scenarios & The “Trench” Experience
A major chemical refinery was expanding its offsite tank farm, locating a new I/O rack over 1,500 feet away from the main control house. Initial copper cable tests showed severe signal degradation and ground loop noise whenever heavy variable frequency drives (VFDs) spun up in an adjacent switchgear room. Dropping a pair of Honeywell 8937-HN modules onto the carrier racks instantly converted the link to fiber optic transmission. The optical isolation cleaned up the communication channel completely, preventing $50,000 in potential project delay costs.
Target Applications:
- Remote Tank Farms & Offsites: Extending Series 8 C300 I/O links beyond standard copper distance limits.
- Refinery Substation & MCC Crossings: Routing control signals through high-noise electrical distribution areas without data corruption.
- Inter-Building DCS Networks: Connecting geographically separated plant control cabinets while maintaining full galvanical isolation.
Transparency SOP: Quality Assurance & Testing
Every Honeywell 8937-HN module undergoes a strict, multi-step quality assurance process before shipment:
- Inbound Visual & Hardware Check: Inspection of optical transceivers, dust caps, structural integrity, and backplane pin alignment.
- Optical Transceiver Power Testing: Measurement of optical output power and receiver sensitivity using calibrated optical meters.
- Live Rig Bench Validation: Installation into a live Honeywell Series 8 test chassis with an active C300 controller to verify communication handshakes.
- Redundancy Switchover Verification: Simulating primary fiber link cuts to confirm instant, zero-packet-loss switchover to the redundant secondary channel.
- ESD Cleaning & Packaging: Optical connectors are swabbed clean, capped, wrapped in static-shielding bags, and standard-packed in custom foam shipping containers.
The Veteran’s Tech Trap Guide
- ⚠️ Protect optical ports at all times! Industrial airborne dust and oil vapors will quickly contaminate open fiber transceivers. Never remove the protective dust caps until you are ready to plug in the optical patch cables.
- ❗ Double-check channel wiring assignments. Swapping Channel A (Primary) and Channel B (Secondary) between local and remote units will cause link synchronization faults in the C300 controller. Always verify Tx/Rx channel pairing during installation.
- ⚠️ Respect minimum fiber bend radii. Tight bends inside crowded wire ducts can cause micro-bends in the fiber optic cable, resulting in signal attenuation and sporadic comm drops. Maintain a minimum 30 mm bend radius on all patch cords.
- ❗ Verify carrier address jumpers. When replacing a failed module, ensure the address pin settings on the mounting carrier match the original configuration before powering on the node.
Frequently Asked Questions
Q: Is the Honeywell 8937-HN identical to the MTL 8937-HN?
A: Yes. The module is co-developed and manufactured by Eaton MTL for Honeywell Experion systems, carrying cross-referenced part numbers for both brands.
Q: Does this module support hot-swapping in an active system?
A: Yes, if installed in a redundant dual-module or dual-link configuration on a supported carrier, you can replace a module without interrupting process control.
Q: Can I run the 8937-HN on a single fiber channel instead of dual redundant links?
A: It will operate on a single fiber line, but the Honeywell C300 controller will generate a missing link diagnostic alarm until the secondary channel is connected.
Q: What fiber cable type is required for the 8937-HN?
A: It uses standard industrial fiber optic cabling (multimode or single-mode depending on distance and optic transceivers utilized in the network design).
Q: What warranty is provided with surplus or refurbished 8937-HN modules?
A: All verified surplus and reconditioned 8937-HN modules include a full 12-month operational warranty.
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