Product Details
Product Overview
The Allen-Bradley 1785-L40B serves as a high-performance central processing unit within the legendary PLC-5 platform. This PLC-5/40 standard processor manages complex automation tasks by coordinating extensive I/O networks through its integrated communication interfaces. It supports up to 48 Kilowords of user memory and handles massive I/O densities, making it a cornerstone for large-scale industrial manufacturing and process control. We supply this unit as 100% Brand New and Original, ensuring your legacy infrastructure maintains peak execution speeds and data integrity without the risks of refurbished hardware.
Technical Specifications
The 1785-L40B combines high-speed logic execution with versatile networking capabilities to manage distributed control systems.
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Manufacturer: Allen-Bradley / Rockwell Automation
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Product Line: PLC-5
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Processor Type: PLC-5/40 Standard Processor
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User Memory: 48 Kilowords (Battery-Backed Static RAM)
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Total I/O Capacity: 2048 (Any mix) or 2048 Input + 2048 Output (Complementary)
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Embedded Communication: 4 DH+/Remote I/O ports; 1 Serial port (RS-232, RS-423, RS-422A)
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I/O Scan Time: 3 ms at 230.4 kbits/s; 7 ms at 115.2 kbits/s; 10 ms at 57.6 kbits/s
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Backplane Current Load: 3.3A @ 5V DC
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Power Dissipation: 17.3 Watts
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Memory Backup: EEPROM Option (1785-ME16 to -M100)
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Battery Type: 1770-XYC
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Operating Temperature: 0 to 60 °C (32 to 140 °F)
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Weight: 3.00 lbs (1.36 kg)
Engineering Advantages
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High-Density I/O Management: The 1785-L40B controls up to 32 universal remote I/O chassis per link. This massive expansion capability allows engineers to consolidate control over expansive production lines into a single processor, reducing hardware overhead and simplifying data synchronization.
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Deterministic Communication: Integrated Data Highway Plus (DH+) and Remote I/O (RIO) ports facilitate high-speed, deterministic data exchange. By selecting the 230.4 kbits/s transmission rate, the processor achieves a rack scan time of just 3 ms, providing the rapid response required for high-speed packaging and assembly logic.
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Robust Memory Protection: The processor utilizes battery-backed Static RAM to prevent data loss during power cycles. For mission-critical permanent storage, it supports EEPROM modules (up to 100K words), allowing for instant program recovery and safeguarding against long-term battery depletion.
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Multi-Standard Serial Connectivity: A single configurable serial port supports RS-232, RS-422A, and RS-423 standards. This eliminates the need for external signal converters when interfacing with legacy weigh scales, barcode readers, or non-Rockwell HMI terminals.
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Environmental Compliance: The module meets IEC 60068-2-14 standards for thermal shock. It operates reliably in environments with rapid temperature fluctuations, ensuring consistent logic execution in unconditioned industrial cabinets.
FAQs
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Which power supplies are compatible with the 1785-L40B?
The processor requires the 1771-P4S, 1771-P6S, 1771-P4S1, or 1771-P6S1 power supply modules. Ensure the power supply provides sufficient current for the 3.3A backplane load of the processor plus any additional I/O modules in the local chassis.
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How do I backup the program without relying solely on the battery?
You can install an optional EEPROM module, such as the 1785-ME64 or 1785-M100. This non-volatile memory stores a master copy of your project, allowing the processor to reload the application automatically if the 1770-XYC battery fails.
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Can the 1785-L40B function as both a scanner and an adapter?
Yes. The embedded communication ports are highly flexible. You can configure the DH+/Remote I/O ports to function as a Scanner (to control remote I/O racks) or as an Adapter (to appear as an I/O station to another master processor).
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Is this a refurbished or surplus unit?
We guarantee this 1785-L40B is 100% Brand New and Original. It ships in factory-sealed packaging with the authentic UPC (612598124015), ensuring you receive a processor with zero operating hours and full hardware longevity.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
Tech & Buying Guide
Understanding Root Causes of Unplanned PLC Stop Mode in Industrial Automation
Modern Programmable Logic Controllers manage execution through distinct operational states: Run, Stop, Start-Up, and Hold. During power-up, a controller initializes memory registers within Stop mode before briefly transitioning to Start-Up mode. During this phase, internal self-diagnostics evaluate system integrity across hardware and user programs. If the controller detects no critical faults, it enters Run mode to execute the control program continuously. However, any severe system anomaly forces the CPU back into Stop mode immediately to prevent erratic machine behavior across the plant floor.
Human-Machine Interface Design: Essential Guide to HMI Selection, Visualization, and Control System Integration
Human-Machine Interfaces (HMIs) serve as the primary operational window into complex industrial automation systems. Modern HMIs convert raw machine data into clear graphical displays, enabling operators to oversee entire manufacturing processes in real time. Instead of relying on physical control panels full of hardwired switches, engineers program interactive screens using intuitive graphics, dynamic color coding, and responsive touch interfaces. Over my 15 years in control systems engineering, I have observed HMIs transform from basic display screens into sophisticated command centers that drive operational efficiency across DCS and PLC environments.
Understanding Safety Relays in Industrial Automation: Architecture, Operation, and Functional Safety
Standard electromechanical relays provide basic electrical isolation between low-voltage control circuits and high-power output loads. A traditional switching relay features a magnetic coil driving mechanical Common (COM), Normally-Open (NO), and Normally-Closed (NC) contacts. However, standard relays pose severe functional risks when deployed in critical safety interlock circuits. High current inrush or mechanical wear can weld contacts together permanently. If contact welding occurs in an emergency stop circuit, pressing the button fails to halt hazardous machinery movements. Consequently, global functional safety standards prohibit standard relays for critical machine guarding functions.