the processing across physically separate locations, it becomes possible to
build a SCADA system that can survive a total loss of any one location. For
some organizations that see SCADA as a super-critical function, this is a
real benefit [ 1 ].
Figure 2. 4 : Third Generation SCADA Architecture- 3 Introduction to Data Acquisition (DAQ)
The purpose of data acquisition is to measure an electrical or
physical phenomenon such as voltage, current, temperature, pressure, or
sound, digitizing the signals for storage, analysis, and presentation on a PC.
Data acquisition systems come in many different PC technology forms to
offer flexibility when choosing a system. Consider the following five
components when building a basic data acquisition system [ 26 ]:- Transducers and sensors: A transducer is a device that converts a
physical phenomenon into a measurable electrical signal, such as
voltage or current. The ability of a data acquisition system to
measure different phenomena depends on the transducers to convert
the physical phenomena into signals measurable by the data
acquisition hardware. Transducers are synonymous with sensors in
data acquisition systems [26].
- Transducers and sensors: A transducer is a device that converts a