LabVIEW control system

The Achilles heel of the AIMS system was the Redwood microvalves that were used for positive flow shut-off Failures generally occurred when the system was first powered up, which suggested that power transients were the cause of many of the problems. Specifically, these valves were thermally actuated, so opening one of the SOVs produced a large transient current draw of about one amp, but for less than % second. Adjustments were made in the LabVIEW control program to prevent the simultaneous actuation of multiple valves. In particular, the valves were not allowed to actuate when power was first applied to the chassis. 

Laborelec s future realisations are vibration analysis, control of inspection robots, and all types of system monitoring. LabVIEW will be used as common tool for developers for the coming years. The synergy effect of a common language for everything concerning acquisition, analysis and processing of data will be beneficial for the whole company. 

Overall, most of the requirements for a process spectrometer/analyzer are straightforward to implement, but they do require attention at the design level. Another important area, which is FTIR-specific, is the user interface and the need to provide for industry standard data communications. Standard software packages do exist for process instrumentation. For prototype development, and even for the front-end interface in a standalone mode of operation, software products, such as Microsoft s Visual Basic and National Instruments LabView, are also important instrumentation development tools. Note that National Instruments also provides important computer-based electronics and hardware that meet most of the computer interfacing, and system control and communications needs for modem instrumentation. 

The second set-up concept from Microinnova, the Lab Experiment Toolbox , has some minor differences from the first concept. It was designed to speed up process development and reduce the time to market of chemicals or compounding products (Figure 4.25) [77]. A modular toolbox has been developed for laboratory-scale experiments. Small tube connections are used to connect various unit operation devices to each other. Process control and user interface are based on Fieldpoint and LabView or Microinnova Process Control. The integration of the sensors into the system is different to the previous concept. The Fieldpoint unit has a front panel, where sensors can be added on a plug-and-play basis. All experimental data are stored in spreadsheets, which can be transferred to common spreadsheet... 

All output signals from temperature sensors and flow controllers are sampled with a commercial acquisition system connected to a PC and data are presented on the screen using a LabView set-up. For the measurements of the cylinder pressure a high speed data acquisition system is installed which also is connected to the PC. 

Film thicknesses were measured with a profilometer (DekTak II). Electron microscope images were obtained using a field-emission scanning electron microscope (JEOL JSM-6401F). Electrical resistances (DC) were measured with a programmable electrometer (Keithley 617). A low-current scanner card and switch system (Keithley 7158/7001) was used to multiplex measurements over ten sensors fi om two sensor arrays. Instruments were controlled and read by computer using a GPIB interfece and LabView software. 

Experimental setup Using EEG data monitoring equipments from Nihon Kohden, an EEG cap with 19 chan-nels/electrodes were placed on the scalp of a subject based on 10-20 electrode placement systems. The robot is connected wirelessly to the EEG machine and a computer. Labview program from a computer was used to send signal to control the robot and at the same time create trigger data to EEG machine. The signal sent wirelessly to the robot via Xbee connection while connection to the EEG machine is via NI-USB6008. 

Fig. 1 shows a 32 X 32 sensors pressure mat (FSA pressure mapping system, Vista Medical Co., Winnipeg, Canada) to receive the pressure distribution data, a tilt adjustable electric wheelchair (Nita International Enterprise Co., Ltd., Taichung County, Taiwan) as inclination controller and a notebook (model X31, BenQ International Co., Ltd., Taipei, Taiwan) and LabVIEW (Version 8.6, National Instruments Co., Austin, Texas) to collect data. 

Modem operating systems like Microsoft Windows are not useful for directly controlling any instraments, since they perform many operations in background and precise time control of signal output would not be possible. Special instrumentation software systems like the widespread LabView are capable of controlling instruments, but such systems are very expansive. Instead, the low-level-high-level principle used here allows a much cheaper solution. 

The dynamics of the write operation were monitored with the circuit shown in Figure 7.25a, which amounts to a bipotentiostat familiar to electrochemists. The S electrode is biased by the write voltage, and the S and D currents are monitored independently and simultaneously. Control of the D voltage permits different bias values for and VsG, and the entire experiment is conducted by a data acquisition system with LabVIEW software. The SG current for PQT and PVFc devices, both containing PEO-EV, is shown in Figure 7.25b for a VsG =-h3 V write pulse lasting 2 s. " ... 

For system automation and integration we have made an actuation/control unit (fig. 4). To operate it the user will insert a biochip in the reader, place sample (with lysis buffer and magnetic beads) in the sample reservoir, and start the LabView program SMART-BioControF which... 

Along the same lines, MEMS devices with on-chip force sensors and actuators have been developed to measure the load-displacement relationship of single nanofibres (Fig. 4.21a) [231]. A MEMS system which is composed of two movable components, namely pulling and bending cantilevers was used by Jaeger et al. (Fig. 4.21b) [232]. Fee et al. [230] utilised a precise screw-type linear actuator and a 1.1 N load cell that were both controlled by a customised LabView program. 

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