Data Acquisition And Control.

Fermilab is developing a facility for vertical testing of SRF cavities as part of its ILC program. The RF system for this facility is based on the proven production cavity test systems used at Jefferson Lab for CEBAF and SNS cavity testing. The design approach is modular in nature, using commercial-off-the-shelf (COTS) components. This yields a system that can be easily debugged and modified, and with ready availability of spares. Comprehensive data acquisition and control is provided by a PXI-based hardware platform in conjunction with software developed in the Lab View programming environment. Data acquisition and control applications

Two methods of transmitting serial data in World System Teletext (WST) format are available. These are the independent data line or `Packet 31' method, and the page format technique. For universal application in a subscription Teletext environment the receiving equipment must be able to accept both forms of transmission. The Multistandard acquisition circuit CIDAC (SAA5250) or CMOS Interface for Data Acquisition and Control, is available to simplify the receiver design. Data acquisition and control software

Introducing LabVIEW and relevant PC-based data acquisition and control experimentation through the revamping of a one unit, three-hour automatic control systems laboratory. The coursework included basic LabVIEW familiarization, computer-controlled projects using student-generated programs, and a final assignment involving the development of a wind tunnel velocity control system.Data acquisition and control systems dacs

All current Data Acquisition Processor boards except the DAP5400a and the DAP5380a have onboard analog and digital inputs and outputs. The DAP5400a and the DAP5380a have high-speed analog inputs.

A one unit, three-hour automatic control systems laboratory course was modified to incorporate LabVIEW-based student-developed controls projects. After learning LabVIEW during the first three weeks of the course, each student was required to develop and perform three PC-based data acquisition and control experiments. The final experiment involved the development of a proportional-integral-derivative (PID) wind velocity control system for a small subsonic wind tunnel. In addition to the course, students and researchers can access the wind tunnel speed control system via the Internet to investigate the tunnel control system.

Data is retrieved from the RAM via CIDAC's parallel interface to a host interface or a microcontroller. The microcontroller itself can be one of several standard types, 8051, 8049, 6801, 6805, etc. Access controls and descrambling are dealt with using the appropriate software in the decoder's microcontroller acting on the corresponding received data. Alternatively, these functions may be performed by the host computer, with the decoder simply acting as a transparent data link and no microcontroller is used in this configuration. The same hardware configuration can be used as a receiver for downloadable software, or as a standard acquisition unit for normal World System Teletext or pages with the host computer used as the display unit.

The sample vial is placed in the sample port. An automatic gas flow system transports the analyte to the analysis chamber which contains the nanomechanical cantilever array. Data acquisition and control is performed by a laptop PC, which also supplies electrical power.

The UTEP educational improvement strategy utilizes modular experiments that can be used throughout the engineering curriculum [e.g., Wicker and Loya, 2000]. As part of this strategy, UTEP obtained a small subsonic wind tunnel, to be used for research and education. With the previously mentioned grants and equipment, a one unit, three-hour automatic control systems laboratory was modified to actively engage students in relevant PC-based data acquisition and control experimentation.

Software description: The reflectometer data acquisition and control program is written in VC++ that works in Microsoft Windows environment. Flow chart of program is given in figure2. The visual interface generated in VC++ makes the program user friendly. Outlook of control program is given in figure3.

This machine was procured from Rikagu International, Japan. This has a Mo anode material (17.5 keV x-rays). A monochromator (uses either a Symmetrical-cut Si(111) crystal or Asymmetrically-cut Si(111) depending on the experiment used) is used to generate a mono-energetic x-rays. The monochromator is placed on a large Huber goniometer head which is driven by DC motors. A HUBER four-circle goniometer is available for placing the sample to carry out the experiments. The data acquisition and control is done with a computer which uses few add-on cards for the purposes with an indigeneously developed programmes.

The experimental setup, includes a small subsonic wind tunnel, a pitot-static probe and pressure transducer, two DC power supplies with GPIB interfaces, and a computer loaded with LabVIEW and a Lab-PC-1200 and GPIB boards. The pitot-static probe provides the velocity feedback measurement required for the PID control system. A pressure transducer measures the pressure from the pitot probe, and is in turn electrically connected to the host computer via the Lab-PC-1200 data acquisition board. The student-generated program monitors the pressure measurement, converts the pressure measurement to a wind tunnel speed, and makes appropriate changes to the wind tunnel speed via a GPIB card connected to the two DC power supplies. The power supplies are connected to a set of DC fans located at the top of the wind tunnel, allowing for variable speed control within the wind tunnel test section [Hennessey et al.

The implementation of a control system in the LabVIEW software environment allows unprecedented flexibility in design and testing [Matey, 1993]. The architecture of the wind tunnel control system is a classic digital system that samples the input signal at discrete time intervals and adjusts the output according to an appropriate control algorithm. The blocks marked with "A/D" or "D/A" change signals from the analog domain to the digital domain, respectively. By actively engaging the students in the control system implementation, the students are developing a more complete understanding of PID control systems and the issues involved in control system implementation [cf., Wicker and Quintana, 2000].

Computer data acquisition and control is used to provide unique capabilities for research and instruction. Using LabVIEW, the students were able to quickly develop the wind velocity control system utilizing a PID control strategy. After developing the PID control system, the students were required to determine the "optimal" gain settings for a pre-determined wind tunnel speed profile.

The program initializes communication port COM1, 2 & 3 at the beginning where monochromator, its encoder and digital multimeter is connected. Along with serial communication devices the GPIB instrument is also initializes. For online data plotting the Microcal Origin software is used. A macro is define that calls stored data file and gives graphical display continuously.

The application of LabVIEW as a rapid prototyping tool in the development of a PID controller allowed students in the automatic control systems laboratory course an unprecedented opportunity to independently produce one such controller. The student created the VI with less than three months of LabVIEW experience, thus validating LabVIEW as the world leader in PC-based data acquisition and experiment control. Furthermore, the use of LabVIEW allowed the students to actively engage in the development of the control system, providing a more fundamental understanding of control system design and implementation. LabVIEW provides an incredible opportunity for real-world relevant laboratory exercises, and the student response to this new approach has been overwhelmingly positive. This flexibility provides UTEP with a valuable asset in both instruction and research.

Sensors that could help some of the most impoverished farmers in Africa maximise their crop yields are being tested at London's Kew Gardens. The sensors gather data on air temperature, humidity, air pressure, light, and soil moisture and temperature - information crucial to making key agricultural decisions about planting, fertilisation, irrigation, pest and disease control and harvesting.

Long-haul Transmission?Railway systems consist of many stations, some of which could be separated by hundreds of kilometers. A network used to integrate operation information from that many stations must be capable of transmitting data over long distances.

With OpenNet Instruments' products, there is no need for a PC in the system to implement these services. These services include: data acquisition and control logic, XML and JAVA support for data and system communications, an email server for sending email alarms, a web server to host pages containing acquired data and control points, and data logging.

The system is very flexible and user friendly; the engineer can configure each unit under test as the test requires. Test data is generated automatically after the test is concluded. And configuration of each unit is saved in a configuration files should the R&D engineers wishes to test the unit again in the future.

The stability and reliability of network communication are at the core of constructing an intelligent railway transportation system. Moxa provides industrial device networking solutions to control and manage data from various sites.