Product Description
The Allen-Bradley 1785-L20C15 is a PLC-5 controller within the enhanced PLC-5 series, specifically the ControlNet PLC-5 sub-series. It integrates local, extended, and remote I/O devices through various communication interfaces into a unified control system. It features a built-in ControlNet phase 1.5 interface for easy integration into ControlNet networks, and shares specifications with other PLC-5/20 controllers. It has a dedicated DH+ port (channel 1A) and a configurable port (channel 1B) for either DH+ or Remote I/O. Channel 0 is an RS232C port supporting ASCII and DF1 protocols. ControlNet enables real-time, high-throughput communication, supporting controller interlocking and I/O control. The 1785-L20C15's ControlNet interface is phase 1.5 and cannot be mixed with older versions. Channel 1B can function as a Remote I/O scanner or adapter. DH+ communication on channels 1A and 1B allows data transfer and programming of other PLC-5 controllers, with cable length dependent on transmission rate. Front panel indicators display battery status, processor mode, I/O force status, and communication status. A key-switch allows selection of RUN, PROG, or REM (Remote) modes, each with specific functionalities. The controller has 16,000 words of user memory, battery-backed RAM, and a slot for an EEPROM program backup module. It supports 512 mixed I/O, 512 analog I/O, and can utilize 77 I/O chassis (12 universal remote). It lacks extended local I/O chassis capability, but can utilize up to 32,000 I/O via ControlNet. ControlNet I/O scan time averages 0.5ms.
Is Your Device Showing These Signs?
The Allen Bradley 1785-L20C15 PLC processor commonly experiences issues such as memory corruption requiring memory clear procedures, backplane communication failures due to faulty I/O modules or corrupted logic, and power supply degradation leading to intermittent operation or complete failure. Program loss or corruption occurs from battery depletion or improper shutdown procedures, necessitating program reloading and verification. Resolving these problems involves troubleshooting the backplane, verifying power supply output, replacing the battery, and restoring the PLC program from a known good backup. Addressing these issues ensures the reliable operation of the PLC in industrial automation applications.
Technical specifications
The Allen-Bradley 1785-L20C15 is a PLC-5 controller designed for ControlNet networks. It features a built-in ControlNet interface (phase 1.5), DH+ ports, and an RS232C port for versatile communication. It offers 16,000 words of user memory, supports a large number of I/O points, and has front panel indicators for status monitoring. A key-switch allows mode selection. While it lacks extended local I/O, it leverages ControlNet for extensive I/O capabilities with a fast scan time.
Our Repair Process for the
1785-L20C15
Our repair process for the Allen Bradley 1785-L20C15 PLC processor begins with a thorough inspection of the backplane, followed by verification of the power supply output to ensure it meets specified voltage and current requirements. If memory corruption is suspected, a memory clear procedure is executed. The battery is replaced to prevent program loss. The PLC program is restored from a verified backup, and all I/O modules are tested to confirm proper backplane communication. The entire system undergoes rigorous testing to guarantee reliable operation in industrial automation applications.
Your Guarantee: Warranty & Lifetime Support
Your satisfaction is our top priority, and we confidently stand behind the quality of our repairs. That's why every repair service is covered by our comprehensive 24-month warranty. Furthermore, we offer lifetime phone support – if you have questions or need assistance related to our repair down the road, we're here to help. Our service commitment is straightforward: we guarantee our work, and if you're not satisfied, we will make it right. Learn More about our Repair process.
Comprehensive Repairs You Can Depend On
We take immense pride in the quality and reliability of our work. Our process goes beyond simply fixing the immediate problem. We perform a comprehensive inspection of your main board (or other equipment) and proactively replace components known to be failure-prone or showing signs of potential future failure. Before any item is returned, it undergoes rigorous functional testing to ensure it meets performance specifications and operates flawlessly. Visit our main Repair Services page to learn more.
Save Significantly
Our primary goal is to save you hundreds, or even thousands, of dollars compared to the cost of new equipment replacement. By repairing existing components, we provide an economical solution that is also eco-friendly. At Roc Industrial, our commitment to integrity and community drives our consistent growth and ensures you receive a reliable, cost-effective solution.
Please Note: Roc Industrial operates as an independent service provider and is not an authorized distributor for the manufacturers or brands mentioned. Consequently, the original manufacturer's warranty is not applicable to items repaired or sold by us. Roc Industrial provides its own 2-year warranty on all repair services performed.