Data acquisition and control system has been designed for Meters Producing Company ASWEGA (Estonia) for flowmeters calibration rig.

Specification:

Data acquisition:

• 32 analog current measurement inputs (0 - 5 mA, 0 - 20 mA, 4 - 20 mA);
• 40 opto-isolated digital inputs;
• 40 opto-isolated pulse/frequency inputs;
• 20 RS232/RS485 serial ports;
• 4 temperature measurement modules.

Control:

• 40 relay outputs;
• Power supply for all control equipment and devices under test.

Dimensions:

• Height 30 cm in 60 x 60 cm 19" Rack (without control computer).

System consists of followed parts:

• main unit;
• external temperature measurement modules;
• power supply;
• control computer.

Main unit contains data acquisition and control electronics and all connectors. It is connected to control computer via two serial ports. Main unit executes real time software that has been loaded from computer.

Computer receives data from the main unit and processes them with the custom software based on Windows NT 4.0 / 2000 and higher.

Terminal panel for all connections is located on the front panel of the main unit.

It consists of 4 types of terminal boards:

• 8 - channel relay output board;
• 9 - channel opto - isolated input board;
• 8 - channel current - to - voltage converter board;
• 8 - channel direct output and direct input boards.

Several types of PC/104 cards operate under control of processor based on AM80C188ES-40. Control software contains built-in ROM monitor and downloadable code.

External temperature measurement modules are connected to the main unit via RS485 interface.

Linear and pulse power supplies provide 5, 7, 12, 24 V.

All system hardware and software has been designed and manufactured by Electronics Design Ltd. PC/104 ADC cards, industrial computer and temperature measurement modules have been manufactured by Axiom Technology Co. Ltd., (Taiwan). See hardware details.

Screen-shots of working system in Moscow: