Data Acquisition Systems
Data acquisition systems (DASs) are instruments with one or more waveform input channels. DASs include analog oscilloscopes (AOSs), digital storage oscilloscopes (DSOs), and DAQs, which have more channels than DSOs or AOSs at higher resolution and lower sampling rates, and with sensor support. DSOs have a graphic display and DAQs do not locally but through support software. The DSO-DAQ distinction is along a functional continuum of differing numbers of channels and waveform sample rates. All DASs acquire waveforms which are electrical functions of time.
The broad definition of DAS used here includes ultrasonic imagers, vacuum-system controllers and rocket launchers, all based on DAQ capability.
DASs are not uncommonly augmented with outputs for control or calibration. AOSs have long had current and voltage outputs for calibrating probes and channels. DAQs often have outputs for controlling devices such as servomotors with PCM interfaces or pulsers for pyrotechnic devices.
Innovatia currently has no project development of AOSs or DSOs (ironically, after about 10 years of AOS and DSO design at Tektronix). There is one DAS project, in complete product form as a thermal energy meter, and in a more general form as the DAS201 MiniDAS. It has been applied to multiple product functions.
The original version of the DAS201 MiniDAS - a single-board instrument with a 6-digit LED display and a 4-switch switch-mouse, for travsersing the menu tree and entering numbers. The 6502-based mC is now obsolete, but the high-level software can be ported to an AVR or ARM single-IC mC, and the circuit-board shrunk by half or more. The DAQ analog core would not be changed, nor would the user-interface electronics.
The DAS201 has two-point auto-calibration for its 6 channels. As designed, 4 channels are input from precision interchangeable thermistors covering 0 to 105 degrees C and pulse inputs on two channels from flowmeters.
The MiniDAS has been applied to the following applications, with designware for them available to Assistants:
Temperature Fan Controller
The DAS210 Huron DAQ is a single-board DAQ. A next-generation MiniDAS, it has an extended number of channels and more sensor support. It also includes several output functions and multiple software functions for mission-oriented applications. It was originally designed to be a sounding rocket test-stand and flight controller.
The DAS210 in its present design has a 6502-based mC with selectable RS-232 or RS-485 serial ports for control interface. For real-time critical missions, the software has a 2-level watchdog timer for recovery from faults.
Designed for scanning the eye, this imager front-end can be applied to other medical or non-medical nondestructive testing applications.