Allen-Bradley OCM-DPR-85-D-ST Fiber Optic Communication Module | Replacement, Equivalent & Selection Guide
The Allen-Bradley (AB) OCM-DPR-85-D-ST is a dual-port fiber optic communication module designed for use in Rockwell Automation PLC and DCS control systems. It provides reliable, noise-immune data transmission over ST-connector fiber optic links, making it ideal for industrial environments with high electromagnetic interference. This page provides full technical specifications, compatible replacement options, equivalent models, and a structured selection guide to help engineers and procurement teams make informed sourcing decisions.
Technical Specifications
- Manufacturer: Allen-Bradley / Rockwell Automation
- Part Number: OCM-DPR-85-D-ST
- Module Type: Fiber Optic Communication Module
- Ports: Dual Port (DPR)
- Wavelength: 850 nm (multimode)
- Connector Type: ST (Straight Tip)
- Fiber Type: 62.5/125 µm or 50/125 µm multimode fiber
- Communication Protocol: DH+ / Remote I/O compatible
- Operating Temperature: 0°C to 60°C (32°F to 140°F)
- Storage Temperature: -40°C to 85°C
- Power Supply: Backplane powered
- Weight: Approx. 900 g (with packaging)
- Certifications: CE, UL listed
- Form Factor: Single-slot PLC rack module
Compatible Replacement & Equivalent Models
The following models are commonly evaluated as replacements or equivalents for the OCM-DPR-85-D-ST. Compatibility depends on your specific rack, firmware version, and network topology — always verify before substitution.
- 1770-KF2 — Allen-Bradley DH+ communication interface; functional alternative for DH+ network bridging
- 1785-KA5 — AB PLC-5 communication adapter; compatible in PLC-5 backplane environments
- 1756-DHRIO — ControlLogix DH+/Remote I/O bridge module; modern replacement for legacy fiber-linked DH+ systems
- 1756-RIO — ControlLogix Remote I/O scanner; suitable for migrating OCM-based RIO networks
- OCM-DPR-85-D-SC — Same module with SC connector instead of ST; verify fiber plant connector type
- Third-party fiber media converters — Moxa, Advantech, or ProSoft fiber-to-copper converters may bridge legacy fiber links to modern Ethernet-based PLCs
Note: Cross-brand replacements require engineering validation. Contact Konmask technical support for compatibility confirmation.
Why Choose the Original Model
- Guaranteed compatibility with existing Allen-Bradley PLC-5, SLC 500, and legacy ControlLogix racks without firmware changes
- Plug-and-play replacement — no re-engineering of network topology or I/O mapping required
- Proven reliability in high-EMI industrial environments (steel mills, chemical plants, power generation)
- OEM-grade fiber optic performance at 850 nm with ST connectors — no adapter or pigtail required
- Minimizes downtime risk during maintenance or emergency replacement scenarios
- Supports legacy system longevity — extends operational life of existing PLC infrastructure without costly migration
Typical Applications
- Factory automation and discrete manufacturing lines using Allen-Bradley PLC-5 or SLC 500 systems
- Remote I/O (RIO) networks in large-scale process plants requiring fiber optic noise immunity
- DH+ network extensions across long distances or electrically noisy environments
- Power generation and utilities with high-voltage interference requiring optical isolation
- Oil & gas upstream/downstream control systems with distributed I/O architectures
- Water treatment and municipal infrastructure with geographically dispersed control nodes
- Automotive assembly lines with high-frequency drive interference
System Compatibility
- PLC-5 Series: PLC-5/10, PLC-5/15, PLC-5/20, PLC-5/30, PLC-5/40, PLC-5/60, PLC-5/80
- SLC 500 Series: Compatible via appropriate communication adapter
- ControlLogix: Legacy integration via 1756-DHRIO bridge (not direct slot replacement)
- Network Protocols: DH+ (Data Highway Plus), Remote I/O
- Fiber Infrastructure: 62.5/125 µm multimode; ST-terminated patch cables and trunk fiber
- Rack Compatibility: 1771-series I/O chassis (verify slot width and backplane voltage)
Selection Guide
Use the following criteria to determine whether the OCM-DPR-85-D-ST is the right module for your application, or whether an alternative should be considered:
- Existing rack type: If you have a 1771-series PLC-5 rack, the OCM-DPR-85-D-ST is a direct fit. For ControlLogix racks, consider 1756-DHRIO instead.
- Connector type: Confirm your fiber plant uses ST connectors. If SC connectors are installed, select the OCM-DPR-85-D-SC variant.
- Number of fiber ports needed: This module provides dual ports (DPR). For single-port requirements, evaluate OCM-SPR variants.
- Network protocol: Designed for DH+ and Remote I/O. If migrating to EtherNet/IP, a ControlLogix platform with 1756-EN2T is recommended.
- Distance requirements: 850 nm multimode fiber supports up to ~2 km typical. For longer runs, consider 1300 nm singlemode variants.
- Budget vs. risk: OEM original minimizes integration risk; third-party alternatives may reduce cost but require validation effort.
Quality Assurance & Sourcing
- All units sourced through Konmask.com are inspected for physical integrity, connector condition, and label authenticity prior to shipment
- Traceability documentation available upon request (batch records, test reports)
- Refurbished units clearly labeled and priced separately from new/surplus stock
- Secure anti-static packaging with moisture barrier for long-term storage protection
- Export compliance screening performed for all international orders
- 30-day return policy on unused, unopened units
How to Order
- Step 1: Confirm your rack type, slot availability, and fiber connector type (ST vs. SC)
- Step 2: Verify quantity and lead time requirements with our team
- Step 3: Add to cart or contact us for bulk pricing and availability
- Step 4: Provide PO number or company details for B2B invoice processing
- Step 5: Receive shipment with packing list and optional test certificate
📧 Email: support@konmask.com
📞 Phone/WhatsApp: +0086 19859288691
🌐 Website: https://Konmask.com
Replacement & Compatibility FAQ
Q: Can the OCM-DPR-85-D-ST replace a 1756-DHRIO in a ControlLogix rack?
A: No. The OCM-DPR-85-D-ST is designed for 1771-series PLC-5 racks. The 1756-DHRIO is the ControlLogix equivalent and is not interchangeable at the hardware level.
Q: Is this module compatible with EtherNet/IP networks?
A: No. This module operates on DH+ and Remote I/O protocols. EtherNet/IP requires a separate communication module such as the 1756-EN2T.
Q: Can I use SC-terminated fiber with this module?
A: No. This variant uses ST connectors. For SC fiber plants, order the OCM-DPR-85-D-SC variant.
Q: What is the maximum fiber run distance?
A: Typically up to 2 km with 62.5/125 µm multimode fiber at 850 nm. Actual distance depends on fiber quality, splice losses, and connector condition.
Q: Do you offer tested/refurbished units?
A: Yes. Refurbished units are available at reduced pricing and are clearly identified. Contact us for current stock and pricing.
Q: Can Konmask provide a certificate of conformance?
A: Yes, upon request for qualifying orders. Contact support@konmask.com with your order details.
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Contact: support@konmask.com | +0086 19859288691
