Measurement Computing CIO-DAS16 - Manual (Page 13)

3 ANALOG CONNECTIONS
3.1 ANALOG INPUTS
Although complete coverage of this topic is well beyond the scope of this manual, the following section provides some
explanations and helpful hints regarding these analog input connections. This section is intended to help you achieve the
optimum performance from your CIO-DAS16/F series board.
You should have a basic understanding of Single-Ended/Differential inputs and system grounding/isolation. If you are
already comfortable with these concepts you may wish to skip to the next section (on wiring configurations).
3.2 SINGLE-ENDED AND DIFFERENTIAL INPUTS
The CIO-DAS16/F provides either eight differential or 16 single-ended input channels. The concepts of single-ended and
differential inputs are discussed in the following section.
Single-Ended Inputs
A single-ended input measures the voltage between the input signal and ground. In this case, in single-ended mode the
CIO-DAS16/F measures the voltage between the input channel and LLGND. The single-ended input configuration
requires only one physical connection (wire) per channel and allows the CIO-DAS16/F to monitor more channels than the
(2-wire) differential configuration using the same connector and onboard multiplexor. However, since the CIO-DAS16/F
is measuring the input voltage relative to its own low level ground, single-ended inputs are more susceptible to both EMI
(Electro Magnetic Interference) and any ground noise at the signal source. Figure 3-1 shows the single-ended input
configuration.
Figure 3-1. Single-Ended Input Configuration
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