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Stochos/Nematron Factory DemonstrationThe Stochos/Nematron exhibit features an advanced, constantly improving on-line continuous process factory. The purpose of this factory is to demonstrate smooth integration of software and hardware technologies that result in cost savings and many other benefits for manufacturers. Some benefits include:
Utilizing Nematron’s Open Control and Paragon modules for the plant control system (PCS) and Stochos ProActive Process Improvement (PPI), the factory provides:
Set points for the speed of the table and for the oven temperature are transmitted to the PCS in accordance with Evolutionary Operation (EVOP) experimental design to drive the color of the product being generated. The effect of non-controlled variables is demonstrated by way of a muffin fan whose position and direction are manually set to arbitrary positions. The set points, determined from the Evolutionary Operation system, follow the response surface as it changes due to muffin fan location and direction. Portions of the data from the factory are also being transmitted to Stochos' SPC Direct package for on-line analysis that monitors the process for out-of-control conditions. Real-time alarms alert the operator should they find an unusual situation - from process observation or a control chart - he or she may utilize the Quality Action Request (QAR). The various modules contained in this integrated system demonstrate the ability to reduce costs, improve plant performance and increase the quality of manufactured products thus proving their value many times over - savings of $250k to $750k per year are reported. Technical Information This document describes the technical aspects of the Stochos/Nematron collaborative project for the IMS Expo. The project demonstrates Stochos Process Optimization software and Nematron’s OpenControl and Paragon software with the addition of Wago I/O modules. Overview: Stochos’ ProActive Process Improvement (PPI) software controls the oven, while Nematron’s OpenControl provides a software interface to the I/O points that is quick, deterministic, and reliable. OpenControl shares the data with Paragon. Paragon interfaces with Stochos’ PPI software via output of current I/O data to a properly formatted text file, which Stochos has the ability to read. Once PID calculations are complete, the PPI software writes new set points to a different text file, which Paragon reads as required. Paragon then updates OpenControl with the new set points. Once OpenControl receives the new set points, they are sent as analog commands to the I/O modules. I/O description: There are four channels of I/O, two input and two output. A "bus coupler" is the controller module that physically connects to a Profibus adapter card in the PC. Input 1: A two-wire K-type thermocouple reads the oven temperature. The thermocouple sends the temperature in @v to the Wago analog input module 750-462, a K type thermocouple module, (or 750-469, which offers diagnostics). The module interprets the signal and outputs a 10 bit analog value to the PC card. 0 degrees C is 0x0000 (hex) or 0 in decimal. 1370 degrees C is 13700 decimal or 0x3594. Input 2: A two wire 0-20 ma signal from a photo eye indicating "brownness." This photo eye is connected to a Wago analog input module 750-452, a 0-20 ma module. The module interprets the signal with 12-bit precision. 0x0000 corresponds to 0 ma and no brownness. 10 ma will be interpreted as black and will have hex value 0x4000 and decimal value 16384. Testing revealed that there is a range of 2 ma between white bread and toast. This will provide >2000 integers of resolution. Additionally, the sensor can determine the presence of bread by outputting values less than approximately 1 ma. Output 1: A two-wire pulse width modulated signal with a nominal voltage of 10 VDC to control the motor speed. The motor is rated at 12 VDC, so we use a Wago optocoupler module to receive the pulse and increase the output voltage. The Wago optocoupler module is 286-752, a positive-switching 24VDC max supply rated at 500ma continuous. The 12 VDC motor supply is connected to the module. As the PWM module increases the pulse width, the optocoupler varies the duty cycle of the 12 VDC supplied to the motor. The Wago PWM module is 750-511. A 12 bit output allows the 12 volt pulses to have a duty cycle of 0-100%. 0x0000 is duty cycle off or pulse width 0%. 0x7FF8 is 100% duty cycle or pulse width 100%, which will drive the motor at full speed. Output 2: A two-wire variable 60 Hz AC voltage ranging from 0-120 VAC to control the heat from the heating element. The element is rated at 120 VAC so we will use a Wago optocoupler module to receive the pulse and increase the output voltage. The Wago optocoupler module is 286-734, a 230 VAC (24V-280V) supply rated at 1 A continuous. 120 VAC element supply is connected to the module. As the PWM module increases the pulse width, the optocoupler varies the duty cycle of the 120 VAC supplied to the element. This signal is supplied from a Wago optocoupler. The aforementioned PWM module (second channel) sets its range. The duty cycle of the pulse will control the output voltage of the optocoupler. A 12 bit output allows the 10 volt pulses to have a duty cycle of 0-100%. 0x0000 is duty cycle off or pulse width 0%. 0x7FF8 is 100% duty cycle or pulse width 100%, which will supply full 120 VAC power to the element. The Wago power supply and a DIN rail hold all modules. Two terminal blocks by Wago connect the devices to the optocouplers and mount the optocouplers on the DIN rail. Additionally there is one purple Profibus cable to connect to the Profibus card. The ProActive Process Improvement system was developed for Sun Microsystems, Inc. workstations running the SolarisTMoperating environment. The Sun hardware/software combination was chosen because of its consistently high marks in quality and reliability testing. All of Sun's workstations and servers use the powerful SolarisTM environment with a wide range of features for ease-of-use and increased productivity. All other software applications (Paragon, OpenControl, SPC Direct) are Windows NTTM-based systems running on Nematron’s high quality Industrial Control Computers (ICCs). Nematron’s ICCs are designed and manufactured for reliable performance in the harshest industrial environments, with innovative features that allow for easy installation, maintenance, and upgrade. |
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