Allen-Bradley 1785-L20C15 PLC-5/20 ControlNet Processor Module – PLC-5 Series C
Imagine a critical production line suddenly halting — conveyors frozen, robotic arms locked, and process data lost — because the central processor that orchestrates every I/O signal and network command has failed. In high-stakes industrial environments running Allen-Bradley PLC-5 architectures, the 1785-L20C15 is not a replaceable commodity; it is the cognitive core of the entire control system. Without it, there is no communication, no logic execution, and no path to recovery. Every minute of downtime translates directly into lost output, safety risk, and costly emergency procurement.
The Allen-Bradley 1785-L20C15 is a mid-range processor within the legendary PLC-5 family, engineered specifically for ControlNet-based distributed I/O architectures. As one of the most widely deployed PLC-5 ControlNet processors globally, the 1785-L20C15 occupies a strategic position in the installed base of automotive, oil & gas, water treatment, and heavy manufacturing facilities. Its combination of deterministic ControlNet scanning, robust memory capacity, and proven field reliability has made it a benchmark for legacy system continuity and long-lifecycle industrial automation projects worldwide.
Technical Specifications
- Part Number: 1785-L20C15
- Series: C
- Platform: Allen-Bradley PLC-5
- Network Interface: ControlNet (onboard)
- Processor Type: PLC-5/20 ControlNet Processor
- Memory: 16K words user memory
- I/O Capacity: Up to 512 discrete I/O (local + remote)
- Communication Ports: ControlNet port (BNC), RS-232 programming port
- Backplane: Compatible with 1771 I/O chassis
- Operating Temperature: 0°C to 60°C (32°F to 140°F)
- Power Supply: Supplied via 1771 chassis backplane
- Firmware: Series C revision
- Manufacturer: Rockwell Automation / Allen-Bradley
Note: Specifications above are based on published Allen-Bradley documentation. Always verify against your system’s actual configuration requirements before ordering.
Key Features & Benefits
- Onboard ControlNet Interface: Native ControlNet port eliminates the need for a separate scanner module, reducing rack space and simplifying network topology.
- Deterministic & Repeatable Scanning: ControlNet’s scheduled communication model ensures time-critical I/O data is delivered with guaranteed bandwidth — essential for motion control and process synchronization.
- 16K Word User Memory: Sufficient for complex ladder logic programs, data tables, and PID loops typical of mid-scale process and discrete manufacturing applications.
- Proven Long-Lifecycle Reliability: The PLC-5 platform has a decades-long track record in harsh industrial environments, making the 1785-L20C15 a trusted choice for legacy system maintenance and life extension projects.
- RS-232 Programming Port: Direct connection to RSLogix 5 programming software for offline program upload/download and online monitoring.
- Drop-in Replacement Compatibility: Series C designation ensures compatibility with existing 1785-L20C Series installations, minimizing re-engineering effort during replacement.
Industry & Equipment Applications
- Automotive Manufacturing: Body welding lines, paint shop conveyors, and assembly transfer systems relying on PLC-5 ControlNet architectures.
- Oil & Gas: Pipeline monitoring stations, compressor control panels, and wellhead automation systems with long-established PLC-5 infrastructure.
- Water & Wastewater Treatment: SCADA-integrated pump stations, filtration control, and chemical dosing systems.
- Food & Beverage Processing: Batch control, filling line sequencing, and CIP (Clean-In-Place) automation.
- Mining & Minerals: Conveyor drive control, crusher sequencing, and plant-wide distributed I/O networks.
- Power Generation: Auxiliary system control in thermal and hydroelectric plants with legacy DCS/PLC hybrid architectures.
System Integration & Compatible Parts
The 1785-L20C15 operates within the Allen-Bradley 1771 I/O platform ecosystem. Common compatible and associated components include:
- 1771-A1B / 1771-A2B / 1771-A3B1 / 1771-A4B: 1771 I/O chassis (4, 8, 12, 16 slot)
- 1771-P4S / 1771-P6S: 1771 chassis power supplies
- 1784-KTX / 1784-KTXD: ControlNet communication cards for programming workstations
- 1786-RPA / 1786-RPCD: ControlNet repeaters for extended network distances
- 1785-L20C / 1785-L40C15: Alternative PLC-5 ControlNet processors for capacity scaling
- RSLogix 5: Required programming software (Rockwell Automation)
- RSNetWorx for ControlNet: Network configuration and scheduling tool
Our Quality Assurance Process
At Konmask.com, every Allen-Bradley 1785-L20C15 unit we supply undergoes a rigorous multi-stage verification process before shipment:
- Visual Inspection: Physical examination for board damage, corrosion, bent pins, and label integrity.
- Authenticity Verification: Cross-referencing part markings, date codes, and series designations against manufacturer records.
- Functional Testing: Where applicable, modules are powered and tested for basic communication and processor initialization.
- Secure Packaging: Anti-static packaging with foam cushioning to prevent transit damage to sensitive electronics.
- Documentation: Each shipment includes a packing list with part number, series, and condition declaration.
How to Order
- Submit an Inquiry: Contact us via the form on this page or email support@konmask.com with your required quantity and delivery timeline.
- Receive a Quote: Our team will respond within 1 business day with pricing, availability, and lead time.
- Confirm & Pay: Approve the proforma invoice and complete payment via your preferred method (T/T, PayPal, or other agreed terms).
- Shipment & Tracking: We arrange export documentation and ship via DHL, FedEx, or UPS with full tracking provided.
- After-Sales Support: Our technical team remains available post-delivery for integration questions and warranty claims.
Why Choose Konmask.com?
- Industrial Automation Specialists: We focus exclusively on PLC, DCS, and automation hardware — not a generalist electronics distributor.
- Global B2B Supply: Serving engineering firms, system integrators, and maintenance teams across Asia, Europe, the Middle East, and the Americas.
- Obsolete & Hard-to-Find Parts: Extensive sourcing network for discontinued Allen-Bradley components with long lead times from OEM channels.
- Technical Pre-Sales Support: Our engineers can assist with compatibility verification, firmware revision matching, and system configuration advice.
- Transparent Sourcing: We clearly declare product condition (new, refurbished, or tested used) and provide documentation upon request.
- Fast Response: Inquiry-to-quote turnaround within 24 hours for standard requests.
Frequently Asked Questions
Q: Is the 1785-L20C15 still in production by Rockwell Automation?
A: No. The Allen-Bradley PLC-5 product line has been discontinued by Rockwell Automation. The 1785-L20C15 is available through authorized surplus and secondary market suppliers like Konmask.com. We recommend contacting us for current stock availability.
Q: What is the difference between 1785-L20C and 1785-L20C15?
A: The “15” suffix in 1785-L20C15 denotes the ControlNet network address node capability (up to 15 nodes on the ControlNet network). The base 1785-L20C supports a different node configuration. Always verify your network design requirements before substituting.
Q: Can the 1785-L20C15 be programmed with RSLogix 5000?
A: No. The PLC-5 platform requires RSLogix 5 (not RSLogix 5000, which is for ControlLogix). Ensure your programming workstation has a licensed copy of RSLogix 5 and a compatible ControlNet or serial interface card.
Q: What condition are the units you supply?
A: We supply units in new (surplus), refurbished, and tested-used condition depending on availability. Condition is clearly stated in the quotation. All units pass our internal QA process before shipment.
Q: Do you provide a warranty?
A: Yes. We offer a standard warranty period on all supplied units. Specific warranty terms are included in the sales agreement. Contact us for details.
Q: Can you supply multiple units for a plant-wide replacement project?
A: Yes. We handle both single-unit emergency replacements and bulk procurement for plant maintenance programs. Please include your required quantity and delivery schedule in your inquiry.
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Original Source: https://Konmask.com
Contact: support@konmask.com | +0086 19859288691
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