The company I work for just acquired a new machine which measures particle size and other variables. The machine comes with its own program that records and analyzes data. However, we would like to bypass this and read the data directly into LabView and therefore be able to filter, organize, and sort it as we wish.
Attached are pictures of the machine setup. The red circle indicates the cable that connects the PC to the machine.
While the machine will run on its own, there will be no signals passed to the PC without a trigger command. This is my first question: how to provide the appropriate command from LabView to the machine to get it to generate the right signals.
From the machine manufacturer:
The Colloidal Dynamics AcoustoSizer II (AZRII) consists of a Central Signal Processing Unit (CSPU) and various sensors, shown in figure 2.1. These are controlled by proprietary application software that runs on a typical MS WindowsTM based computer (PC).
Under direction of the application software, the CSPU generates sinusoidal voltage pulses over a sequence of prescribed frequencies between about 1 and 20 MHz. These pulses are applied to the Electrokinetic Sonic Amplitude and attenuation (ESA) sensor, where they generate ultrasonic signals in the colloid.
These ultrasounic signals, which contain information about the particle size and charge, are converted to voltage pulses by transducers in the ESA/attenuation sensor, and the pulses are then directed back to the CSPU for signal processing. The processed signals are passed to the PC, along with data from the pH, temperature and conductivity sensors. At the end of the measurement phase, the data is analysed in the PC to determine particle size and zeta potential.
More on the measurement process:
A typical measurement sequence proceeds as follows:
The PC issues instructions to the CSPU to apply high voltage excitation pulses at prescribed frequencies to the ESA/attenuation sensor. This is done in two modes, ESA and attenuation.
In the ESA measurement this voltage pulse is applied across two flat, parallel electrodes that are in contact with the suspension. The suspension flows vertically upwards between the electrodes through a polyphenylenesulphide (PPS) spacer in the ESA sensor. One of the electrodes is coated onto an acoustic delay line, at the opposite end of which is mounted a thin ultrasonic transducer. The applied voltage pulse causes the colloidal particles (which are nearly always electrically charged) to shake backward and forward. This motion generates sound waves, a phenomenon known as the Electrokinetic Sonic Amplitude, or ESA effect. The ESA sound waves pass from the suspension along the glass delay line. When they reach the end of the delay line, the soundwaves generate a voltage across the transducer. The voltage pulse then passes through the signal processing circuitry of the CSPU. The Fourier Transform of the pulse is determined by the CSPU and then passed on to the PC. This Fourier Transform is a complex number having both amagnitude and phase (or argument).
At present we measure at thirteen different frequencies, so at the end of the ESA measurement sequence we have thirteen ESA amplitudes and thirteen phases stored in the PC. This set of quantities is called the ESA spectrum.
In the acoustic attenuation measurement the CSPU output pulse is applied to a piezo-electric transducer. This generates a sound wave pulse that passes through the suspension. This pulse and various reflections that come in later in time are all measured, stored and analysed using Fourier Transforms as in the ESA measurements.
At present we measure at thirteen different frequencies, so at the end of the attenuation measurement sequence we have thirteen attenuation amplitudes and thirteen phases stored in the PC. This set of quantities is called the attenuation spectrum.
Any help would be greatly appreciated!!!
