Signal conditioning
To render the measuring signal into more suitable form
a) Filtering to remove the random noise
b) Conversion from one signal form to another (current
to voltage).
3) Multiplexer
Switching device connected in series with each input channel
from the process. Used to time-share the analog-to-digital
converter (ADC) among the input channels. The alternative is
to have separate ADC for each input channel.
4) Amplifier
Are used to scale the income signal (up or down) to be
compatible with the range of analog-to-digital converter.
5) Analog-to-digital converter (ADC)
Convert the incoming analog signal into its digital
counterpart.