Simultaneous Time Sampling for Heterogenous Multichannel Data Acquisition

Data Acquisition devices play a vital role in our ubiquitous industrial 
control systems. This is due to the increasing need to gathered data to aid in 
automatic decision-making process. Heterogenous analog data require 
various configurations to be able to reconstruct input data properly. Often, 
a single analog to digital conversion is used per acquisition channel, but 
most frequently a multi-channel data acquisition device is used with a 
constant sampling period for all channels. It is obvious that the dedicated 
analog to digital converter per channel is expensive choice, especially if the 
converter device is of high speed. Alternatively, a single analog to digital 
converter is shared by multiple channels. However, sharing such analog to 
digital conversion device requires the use of a real-time scheduling 
algorithm. 
In this paper, we firstly present a survey of current real-time multichannel 
data acquisition sampling techniques. Then, we utilize synthetic signals 
with different frequencies to study the Simultaneous Time Sampling 
problem in multi-channel heterogenous data acquisition systems. This 
problem causes failure of the schedule, thus lead to data loss, or data 
corruption. Our aim is to compare the effectiveness of such scheduling
techniques in addressing such problem. Then, we conclude with a 
recommendation for a possible solution that can reduce the failure rate of 
multi-channel scheduling systems that are used for a single analog to digital 
conversion device.