First, DAQ is an abbreviation for data acquisition. A DAQ module is also commonly referred to as a USB or serial I/O module. Typically, offered as a family of products, DAQ modules provide a remote method of acquiring sensor-based data without placing a full data acquisition solution in an environment not suitable for a system, or where that environment precludes the use of a typical A/D data acquisition board due to excessive noise or the need for complex signal conditioning.

A typical DAQ module family includes modules for remote measurement of temperature, strain, stress, pressure, flow for sensors, 4-20 mA currents, digital signals, frequency, etc. These modules can also be commanded to output a voltage, current, digital signal, or activate relays.

To instruct a DAQ module to acquire data from a sensor or to output a signal or to activate a relay in a module, a set of commands are used. These commands are sent via an RS-485 serial communication line that connects a module with a PC.

In the case of a DAQ module for thermocouple measurement, a simple set of commands are used to: read the temperature, read the CJC temperature, set high and low alarm limits, enable and disable, calibration, and more.

A DAQ module can be connected in groups or clusters to create a network of modules. The variety of modules available for analog and digital I/O functions will allow you to configure a remote data acquisition network to meet most applications.

Measurement Computing Corporation offers the largest selection of PC-based data acquisition and measurement products. Shop our online catalog by selecting a category above. From PCI, USB, PC/104, ISA, and PCMCIA bus boards to external systems based on USB, RS-232, RS-422, RS-485, and GPIB interfaces; Measurement Computing has everything you need for your PC-based data acquisition and control applications.