Researchers replaced the existing 200 I/O-point PLC controller - along with 2000 lines of antiquated PLC ladder logic - to create a more efficient, rugged and easily upgradeable system
Researchers at the University of Colorado at Boulder recently implemented National Instruments's programmable automation controllers (PACs) and the National Instruments Labview graphical development environment to streamline experiments involving a 400g-tonne centrifuge, one of the USA's most powerful centrifuges capable of spinning two tonnes of material at 200 times the force of gravity.
Using industrial PXI chassis and Labview real-time controllers, researchers replaced the existing 200 I/O-point PLC controller - along with 2000 lines of antiquated PLC ladder logic - to create a more efficient, rugged and easily upgradeable system that reduces system setup time and increases reliability.
Researchers working with large centrifuges face unique challenges including a demanding environment, the need to control large DC drives and the requirement to perform both control and data acquisition on several hundred I/O points.
The ruggedness, modularity and reliability of PXI made it ideal for replacing the centrifuge's existing PLC with an NI PXI-8176 embedded controller running Labview real-time software.
Researchers bolted the new PXI system less than one-twentieth the size of existing PLC system - into the same location as the original PLC.
PXI offered I/O compatibility with the existing PLC system, helping researchers reuse original wiring and replace hundreds of individual conductors with standard category 5 ethernet.
In addition, researchers replaced the existing collection of data acquisition equipment with a single PXI-based PAC running a Windows OS and Labview.
"The rugged PXI form factor was ideal for withstanding stresses in industrial settings like the centrifuge, and its modularity and high level of integration increased the reliability and productivity of the system," said Robert Wallen, professional research assistant in the University of Colorado at Boulder Department of Civil, Environmental and Architectural Engineering.
"We also saw substantial savings by using Labview to program both the control and data acquisition systems, and with Labview and PACs, we were able to reduce the system setup time by 75%".
By using a single development environment for both the centrifuge control and data acquisition systems, researchers saved development time by reusing existing code and replacing 2000 lines of antiquated ladder logic code with Labview code.
Researchers used a single development environment, Labview, and flexible hardware to create a solution for their control and data acquisition needs in a minimal amount of time with substantial cost savings compared to purchasing a new PLC control system.
National Instrument says its PACs combine the flexibility of PCs with the ruggedness and reliability of PLCs.
The NI PAC platform consists of a broad range of industrial hardware all programmed with Labview, from PXI for industrial control and data acquisition applications, to Compact FieldPoint for distributed I/O and control, or CompactRio for FPGA-based control.
National Instrument says its PACs are unique because they offer integration with motion and vision and are based on commercial technologies.
"The centrifuge control application at the University of Colorado at Boulder illustrates how flexible hardware and a single development environment can replace control systems traditionally implemented with PLCs," said Ray Almgren, National Instruments vice president of product marketing and academic relations.
"In addition, the use of NI PACs at this leading academic institution is an example of the National Instruments commitment to supporting research and teaching with advanced technology as professors and researchers work to solve the challenges of tomorrow and train the engineers of the future."