Hardware Configuration; Differential Input Mode; Single-Ended Input Mode; Non-Referenced Single-Ended Input Mode - Measurement Computing PCI-DAS6034 User Manual

PCI-DAS6034 & PCI-DAS6035 User's Guide
We recommend that you allow your computer to warm up for at least 15 minutes before
acquiring data with the PCI-DAS6035/6034 series boards. The high speed components used
on the board generate heat and it takes this amount of time for the board to reach steady state
if it has been powered off for a significant amount of time.
2.4

Hardware Configuration

All of the hardware configuration options on the PCI-DAS6035/6034 are software controlled.
You may select some of the configuration options using InstaCal. The analog input
configuration (16 single-ended or eight differential channels), the edge used for triggering
when using an external pacer and the source for the two independent counters are all
selectable using InstaCal. Once selected, any program that uses the Universal Library will
use these selections to initialize the hardware according to these selections.
Following is an overview of the available hardware configuration options for the PCI-
DAS6035/6034. There is additional general information regarding analog signal connection
and configuration in the Guide to Signal Connections (available on our web site at
http://www.measurementcomputing.com/signals/signals.pdf).

2.4.1 Differential Input Mode

When all channels are configured for differential input mode, eight analog input channels are
available. In this mode, the input signal is measured with respect to the low input. The input
signal is delivered through three wires. The wire carrying the signal to be measured connects
to CH# IN HI, the wire carrying the reference signal connects to CH# IN LO, and the third
wire is connected to LLGND. Differential input mode is the preferred configuration for
applications in noisy environments or when the signal source is referenced to a potential other
than PC ground.

2.4.2 Single-Ended Input Mode

When all channels are configured for single-ended input mode, sixteen analog input channels
are available. In this mode, the input signal is referenced to the board's signal ground
(LLGND). The input signal is delivered through two wires. The wire carrying the signal to
be measured connects to CH# IN HI and the other is connected to LLGND.

2.4.3 Non-referenced Single-Ended Input Mode

This mode is a compromise between differential and single-ended modes. It offers some of
the advantages of each mode. Using non-referenced single-ended mode, you can still get
noise rejection but not the limitation in the number of channels resulting from a fully
differential configuration. The possible downside is that the external reference input must be
the same for every channel. It is equivalent to configuring the inputs for differential mode
and then tying all of the low inputs together and using that node as the reference input.
When configured for non-referenced single-ended input mode, sixteen analog input channels
are available. In this mode, each input signal is not referenced to the board's ground, but to a
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Installation