Search NASA⌕ Search

SEARCH · Search NASA

Results for “PLC”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2017

Feasibility of Powerline Communications (PLC) on Future Spacecraft: EMI/EMC Test Results on COTS PLC Technology

Cable harnessing mass continues to be a problem for spacecraft development, particularly with increasingly complex payloads and constraints to their mass and costs. As a strategic initiative to reduce cable harnessing on flight missions, NASA JPL’s Powerline Communications (PLC) research and technology development (R&TD) effort investigates the ability to combine power and data onto the same cable conductors. Research and development of PLC technology, including testing of commercial off-the-shelf (COTS) modules and design of custom PLC unit, aim to articulate the opportunity to infuse this technology into NASA flight projects. This paper illustrates the feasibility of Powerline Communications on future spacecraft through Electromagnetic Interference/Compatibility (EMI/EMC) testing on COTS PLC components including conducted emissions and susceptibility as well as radiated emissions and susceptibility.

Mitchell, Andrew W.↗
NASA NTRSDate not supplied

Verifying PLC Programs via Monitors: Extending the Integration of FRET and PLCverif

Verification of Programmable Logic Controller (PLC) programs requires reasoning about propositions qualified in terms of time. CERN’s PLCverif, an open-source tool for the analysis of safety-critical PLC systems, uses Linear Temporal Logic (LTL) for the specification of properties. Until now, PLCverif depended on third-party tools that accept LTL specifications to perform verification. However, our experience with industrial PLC programs shows that, to overcome analysis limitations, a wide range of techniques are needed to successfully verify complex properties. In this paper, we extend PLCverif to enable PLC program verification of pure-past LTL (PLTL) safety properties with assertion-based verification tools. To this end, we take an algorithm from the runtime-monitoring domain, apply it to bounded model checking of PLC programs, and implement it in PLCverif. We extend the integration of NASA’s Formal Requirements Elicitation Tool (FRET) into PLCverif to use PLTL properties generated with FRET. In addition, we leverage the program structure induced by the PLC scan-cycle for a state-space reduction. Finally, we expose the algorithm to a real-world case study of critical systems at CERN.

Formal verification↗
NASA NTRS2013

The Integration of DCS I/O to an Existing PLC

At the NASA Glenn Research Center (GRC), Existing Programmable Logic Controller (PLC) I/O was replaced with Distributed Control System (DCS) I/O, while keeping the existing PLC sequence Logic. The reason for integration of the PLC logic and DCS I/O, along with the evaluation of the resulting system is the subject of this paper. The pros and cons of the old system and new upgrade are described, including operator workstation screen update times. Detail of the physical layout and the communication between the PLC, the DCS I/O and the operator workstations are illustrated. The complex characteristics of a central process control system and the plan to remove the PLC processors in future upgrades is also discussed.

Sadhukhan, Debashis↗
DOE OSTI2025

Innovative PLC Design for Optimized Potable Water Managment

My project here at Idaho National Laboratory (INL) was to work on Potable Water PLC Design (Programmable Logic Controllers). I was tasked in making a new panel design for the PLC system that will be moved from TRA BLDG 696 to TRA BLDG 608. This design needed to be updated since the old PLC system being about 20 years old. The manufacturer of the MicroLogix 1200 life expectancy showed it to be 10-20 years, and the system was discontinued in 2017. The new system we implemented was called CompactLogix Controller 5380, along with a new 24 VDC/10 Amp Power Supply. I made a design using Microsoft Visio, with the new material. But we needed to add it onto an Aluminum Panel that the system will be mounted onto, we need Unistrut’s for the aluminum panel to be mounted to. Some of the material we will still be using, like the R1 Alarm Relay, will be moving with the PLC system. The rest of the material will be new supplies that need to be updated systems, which the site is waiting for to complete the PLC system.

47 - OTHER INSTRUMENTATION↗
NASA NTRS2008

Automated Translation of Safety Critical Application Software Specifications into PLC Ladder Logic

The numerous benefits of automatic application code generation are widely accepted within the software engineering community. A few of these benefits include raising the abstraction level of application programming, shorter product development time, lower maintenance costs, and increased code quality and consistency. Surprisingly, code generation concepts have not yet found wide acceptance and use in the field of programmable logic controller (PLC) software development. Software engineers at the NASA Kennedy Space Center (KSC) recognized the need for PLC code generation while developing their new ground checkout and launch processing system. They developed a process and a prototype software tool that automatically translates a high-level representation or specification of safety critical application software into ladder logic that executes on a PLC. This process and tool are expected to increase the reliability of the PLC code over that which is written manually, and may even lower life-cycle costs and shorten the development schedule of the new control system at KSC. This paper examines the problem domain and discusses the process and software tool that were prototyped by the KSC software engineers.

Leucht, Kurt W.↗
DOE OSTI2024

PLC Vulnerabilities and Mitigations

Programmable Logic Controllers (PLCs) are used extensively in many high-importance industrial and nonindustrial settings including controlling elevators, manufacturing machines, and utility facilities such as power and natural gas, however cybersecurity protection for them has been neglected. Within recent years, PLCs have been put under more security scrutiny and experts have advocated for changes from the addition of protocol encryption and network segmentation to intrusion detection systems on the PLCs themselves. While PLC security is critical, a large portion of the PLCs available today will never receive these changes due to being legacy or the difficulty of overhauling the security on existing systems. Due to the infeasibility of applying many recommended security measures towards currently available machines, we aim to provide realistic and affordable best practices for hardening PLCs. We will first conduct security analysis and consider attack vectors within our target PLC. Once we’ve analyzed the device’s security, we will evaluate a variety of mitigation methods and create guidelines to effectively reduce the threat posed by PLC attacks with minimal disruption to operations.

42 ENGINEERING↗
NASA NTRS2008

Generating Safety-Critical PLC Code From a High-Level Application Software Specification

The benefits of automatic-application code generation are widely accepted within the software engineering community. These benefits include raised abstraction level of application programming, shorter product development time, lower maintenance costs, and increased code quality and consistency. Surprisingly, code generation concepts have not yet found wide acceptance and use in the field of programmable logic controller (PLC) software development. Software engineers at Kennedy Space Center recognized the need for PLC code generation while developing the new ground checkout and launch processing system, called the Launch Control System (LCS). Engineers developed a process and a prototype software tool that automatically translates a high-level representation or specification of application software into ladder logic that executes on a PLC. All the computer hardware in the LCS is planned to be commercial off the shelf (COTS), including industrial controllers or PLCs that are connected to the sensors and end items out in the field. Most of the software in LCS is also planned to be COTS, with only small adapter software modules that must be developed in order to interface between the various COTS software products. A domain-specific language (DSL) is a programming language designed to perform tasks and to solve problems in a particular domain, such as ground processing of launch vehicles. The LCS engineers created a DSL for developing test sequences of ground checkout and launch operations of future launch vehicle and spacecraft elements, and they are developing a tabular specification format that uses the DSL keywords and functions familiar to the ground and flight system users. The tabular specification format, or tabular spec, allows most ground and flight system users to document how the application software is intended to function and requires little or no software programming knowledge or experience. A small sample from a prototype tabular spec application is shown.

Source record↗
DOE OSTI2026

PLC Integration for the Horn A Magnetic Field Mapping Device

This presentation summarizes the integration of a programmable logic controller (PLC) into the Horn A magnetic field mapping device for the Long-Baseline Neutrino Facility (LBNF). The device is used to position magnetic field probes along the centerline of the Horn A inner conductor to verify that the magnetic field within this region is approximately zero. The presentation covers the PLC hardware and electrical integration, stepper motor and encoder control, ladder logic development, mechanical integration, and system testing. Results include successful bidirectional motion and encoder feedback for the translation and rotation axes, as well as characterization of translational motion for repeatable probe positioning.

Bitakis, Kayla [Unlisted, US, IL]↗
NASA NTRS1991

The use of programmable logic controllers (PLC) for rocket engine component testing

Application of PLCs to the rocket engine component testing at a new Stennis Space Center Component Test Facility is suggested as an alternative to dedicated specialized computers. The PLC systems are characterized by rugged design, intuitive software, fault tolerance, flexibility, multiple end device options, networking capability, and built-in diagnostics. A distributed PLC-based system is projected to be used for testing LH2/LOx turbopumps required for the ALS/NLS rocket engines.

Nail, William↗
NASA NTRS1993

Comparative analysis of different configurations of PLC-based safety systems from reliability point of view

The study of a comparative analysis of distinct multiplex and fault-tolerant configurations for a PLC-based safety system from a reliability point of view is presented. It considers simplex, duplex and fault-tolerant triple redundancy configurations. The standby unit in case of a duplex configuration has a failure rate which is k times the failure rate of the standby unit, the value of k varying from 0 to 1. For distinct values of MTTR and MTTF of the main unit, MTBF and availability for these configurations are calculated. The effect of duplexing only the PLC module or only the sensors and the actuators module, on the MTBF of the configuration, is also presented. The results are summarized and merits and demerits of various configurations under distinct environments are discussed.

Tapia, Moiez A.↗
DOE OSTI2024

Primary Pump Motor Area - Transfer Fan Replacement PLC Design

My poster is about a project that I have worked on in my time at ATR as an intern. The Heating and Ventilation Control Panel (HVB-1) controls thirty-five heating and ventilation fans within the Advanced Test Reactor. This control panel needs replacement, as many of the components inside the existing panel are becoming old and degrading. In preparation for this replacement effort, concepts and component identification for the new control panel needed to be developed. Instead of replacing the new panel with replacement mechanical components, a Programmable Logic Controller (PLC) is proposed as a solution. Although multiple fans are associated with this panel, my poster focuses on the replacement design for the Primary Pump Motor Area Transfer Fan. This will provide an example of how the entire cabinet may be upgraded.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2025

Modernization of PLC-Based Control Systems at SNS

When the SNS site was built around 20 years ago, the Conventional Facilities (CF) control systems were de-signed using 2 communication protocols to allow pro-grammable logic controllers (PLCs) to interface with motors, variable frequency drives (VFDs), and remote input and output (I/O) devices. The protocol chosen to control motors and VFDs is DeviceNet, a CANbus-based protocol developed by Allen-Bradley, a subsidiary of Rockwell Automation. The protocol chosen to communi-cate with remote I/O is ControlNet, another protocol developed by Allen-Bradley. Both of these protocols are obsolete and present reliability and maintainability is-sues, particularly DeviceNet. As the Control Systems Section at SNS is working to modernize control systems throughout the machine, a major goal for PLC-based systems is to remove the obsolete communication proto-cols in favor of standard, ubiquitous Ethernet. To this end, any new VFDs installed use Ethernet communica-tion. Many VFDs are currently being replaced in the Central Utilities Building (CUB) and the Central Exhaust Facility (CEF) and are being removed from DeviceNet in favor of Ethernet communication. Planning is underway to retrofit Eaton Intelligent Technology motor control centers (MCCs) in the Target Building to remove particu-larly troublesome DeviceNet adaptors and replace them with Ethernet adaptors for each motor starter. The Con-trolNet network in the CUB has been demolished, with I/O drops integrated into a local Ethernet network, im-proving sustainability and maintainability.

Beaushaw, Isaiah [ORNL]↗
NASA NTRS2003

Rockwell Automation PLC-5 Lands Stennis Space Center with a Reliable, Flexible Control System

Ever since the first rocket was launched, people have been infatuated with the vast and unchartered frontier of space. Whether it's visiting a space center or watching a shuttle launch, people are waiting to see what will be discovered next. And even though orbiting the Earth or taking soil samples form the Moon now seems effortless, decades worth of behind-the-scenes work have helped the U.S. space program get to this point. Even today, NASA must take every precaution to ensure equipment is up to the endeavor of setting foot on the moon. As part of the initial push to put the first man on the moon, NASA established the John C. Stennis Space Center, Hancock County, Mississippi in 1961 for space engine propulsion system development. Today, Stennis has three major test complexes where engine and component testing is carried out and integrated into full motion systems for space shuttles and vehicles as well as secondary testing facilities. With different products being tested throughout the facilities, Stennis was in need of an automation system that could link the operations. By integrating a control system based on a Rockwell Automation's flexible and reliable PLC-5 controller, Stennis was able to implement projects more efficiently and focus its efforts on getting the next generation of products ready for space.

Epperson, Dave↗
NASA NTRS1994

Effects of silver ions (Ag+) on contractile ring function and microtubule dynamics during first cleavage in Ilyanassa obsoleta

The terminal phase of cell division involves tight constriction of the cleavage furrow contractile ring, stabilization/elongation of the intercellular bridge, and final separation of the daughter cells. At first cleavage, the fertilized eggs of the mollusk, Ilyanassa obsoleta, form two contractile rings at right angles to each other in the same cytoplasm that constrict to tight necks and partition the egg into a trefoil shape. The cleavage furrow contractile ring (CF) normally constricts around many midbody microtubules (MTs) and results in cleavage; the polar lobe constriction contractile ring (PLC) normally constricts around very few MTs and subsequently relaxes without cleavage. In the presence of Ag+ ions, the PLC 1) begins MT-dependent rapid constriction sooner than controls, 2) encircles more MTs than control egg PLCs, 3) elongates much more than control PLCs, and 4) remains tightly constricted and effectively cleaves the polar lobe from the egg. If Ag(+)-incubated eggs are returned to normal seawater at trefoil, tubulin fluorescence disappears from the PLC neck and the neck relaxes. If nocodazole, a drug that depolymerizes MTs, is added to Ag(+)-incubated eggs during early PLC constriction, the PLC is not stabilized and eventually relaxes. However, if nocodazole is added to Ag(+)-incubated eggs at trefoil, tubulin fluorescence disappears from the PLC neck but the neck remains constricted. These results suggest that Ag+ accelerates and gradually stabilizes the PLC constriction by a mechanism that is initially MT-dependent, but that progressively becomes MT-independent.

Non-NASA Center↗