Diamond-MM has all the primary features you expect in a high-performance analog I/O board at a reduced price. The analog input circuit uses a 12-bit A/D converte and can be configured for single-ended or differential input wiring, as well as unipolar or bipolar input ranges. It also offers 10 different input ranges, so it can work with a wide variety of input signals. The maximum A/D conversion rate is approximately 2,000-20,000 per second using interrupts (depending on the operating system) or 100,000 per second using DMA.
Two optional analog outputs provide 12-bit resolution over a 0-5V or user-adjustable output range with 8mA drive current and 4uS settling time. The D/A can also be used as a digital attenuator for an analog signal fed into one of the reference inputs.
The board contains 8 digital inputs and 8 digital outputs. It has an on-board 82C54 counter/timer chip to control the A/D sampling rate and provide general purpose counting functions.
Diamond-MM is available in only one model now: with analog outputs and in industrial (-40ºC to +85ºC) operating temperature range.
Analog Input Ranges
Diamond-MM supports multiple analog input voltage ranges, including both unipolar (+ only) and bipolar (+ and) ranges. In addition, a gain amplifier circuit allows you to reduce the input range to handle smaller signals.
To get the best resolution, select the smallest input range that is large enough to cover the entire range of your input signals. You can also install a resistor to customize the range exactly to your requirements. Note: On any A/D converter, the input range is the same as the full-scale A/D range divided by the gain. On Diamond-MM, the full-scale A/D range is 0-5V in unipolar mode and ±5V in bipolar mode.
Analog Output Ranges
The full-scale analog output voltage range is unipolar and is preset to 0 - 5V. However, you can adjust this range anywhere from 0 - 4V to 0 - 10V by adjusting a potentiometer on the board. You can also supply an external reference signal to each DAC individually to select unique ranges for each output channel. If the reference signal is an AC waveform (e.g. an audio signal), then the DAC can be used as an attenuator (volume control).
A/D Conversion Methods and Rates
To provide flexibility in integrating with your application, Diamond-MM offers several methods of controlling A/D conversions. An A/D conversion can be triggered in 3 different ways: software command, external trigger, or on-board pacer clock. After the conversion is done, the data can be transferred from the board to system memory in 3 ways: software command, interrupt routine, or DMA transfer. Different conversion rates require the use of different transfer methods:
- Software command 2,000/sec max (approx.)
- Interrupt routine 20,000/sec max (approx.)
- DMA transfer 100,000/sec max (board limit)
Universal Driver Software
Universal Driver software provides a high-level programming library for DMM and all of Diamond Systems’ I/O boards, as well as the data acquisition circuitry on our SBC boards. All the features described above are supported with easy-to-use function calls, resulting in a reduced learning curve and shortened application development time. The Universal Driver works with Linux, Windows 2000/XP, Windows CE and DOS. Application examples and projects are included for each function, each board, and each operating system to provide a quick starting point for learning and development.