For all its basic elements, what really makes a machine tick is the programming of the intelligent elements. For larger, more-flexible machines, there can be many software packages in play. A worst-case software scenario for machine builders is a HMI package from one supplier, a soft PLC package from a second, a motion package and/or a vision package from yet anothereach based on its own unique code. Machine builders too often are stuck with customizing drivers to make machine elements talk to each other.
It can help if certain HMI, logic, and motion functions are consistent from machine to machine, with some of the previously developed functions portable to new machines.
We use PC-based technology, so we buy a Visual Basic and OPC server license for each application, says Dave Cleveland, president, Timberline Automation, Littleton, Colo. We develop the HMI in VB, and use the OPC server to talk to the specified PLC. Timberline, a machine control and vision integrator, transports very little code from one application to another, but has developed functional kernels to build onto each application. Most of our HMI screens have a similar look and feel, but are different for each application, particularly vision projects, Cleveland says. We must provide operator access to image adjustments without allowing them into the main program. This requires a VB interface from our vision supplier, Cognex, to implement, and its unique for each installation. However, we have to become more efficient, so were looking for standard, modular software packages that connect to anything.
Timberline is considering products from Hurco Automation Ltd. (HAL), a global supplier of PC-based machine controls. HAL provides machine controllers that include HMI, IEC-compliant soft PLC and SCADA software, plus drivers for multiple fieldbus networks and various Ethernet platforms, says Jacob Pien, HALs president.
National Instruments' LabView long has been used as a platform for data collection. NI has progressed into real-time applications with an extension to LabView (RTX). This allows high-speed motion and vision to be integrated into the LabView HMI and data acquisition platform. We supply a standard development package, but integrators and machine builders often customize their solution on LabView to differentiate themselves, prevent machine commoditization, and protect intellectual property, explains Arun Veeramani, product manager, LabView DCS.
Integrated Industrial Systems (I2S), Yalesville, Conn., a builder of precision rolling mills and thickness gauges, used PLCs for years to automate its mills. We use a gamma-ray sensor that requires high-speed, accurate, analog I/O with advanced processing to convert the signal from the sensor to a metal thickness value, says Clark Hummel of I2S. The PLCs that automate the mills dont provide the high-speed analog I/O and processing required. I2S now uses NIs CompactRIO PAC on its mills, with the only customization being the programming of the FPGA.
From another perspective, Software Toolbox provides tools that adapt to equipment through a set of OPC server tools. Machinery OEMs have a strong incentive to reduce the cost of purchased product content on each machine to increase profitability, says John Weber, Software Toolboxs president. To do that, startup time for each machine must be minimized.
Metrics LLC, Rancho Santa Margarita, Calif., a manufacturer of custom injection molding machines for large, structural-foam parts, always had to develop its controls in-house to be competitive. This included drivers for communicating to its PLCs.
To reduce commissioning time that included frequent software rework, Metrics chose Software Toolboxs Top OPC server to interface to its PLCs and integrate OPC with Metrics VB application. The OPC server, an OPC Data ActiveX, makes connections to our VB HMI easy to set up; the Industrial Gadgets ActiveX lets us enhance our user interface; and the technical support expertise helps bring it together, says Scott Gee, Metrics controls engineer. We reduced development time significantly, which allowed us to focus on areas that enhance our proprietary knowledge of the process.
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