National Instruments PCI-1200 - Manual (Page 21)

Chapter 2 Installation and Configuration
PCI-1200 User Manual 2-4 © National Instruments Corporation
While reading the following paragraphs, you may find it helpful to refer to
the
Analog Input Signal Connections section of Chapter 3, Signal
Connections , which contains diagrams showing the signal paths for the
three configurations.
RSE Input (Eight Channels, Reset Condition)
RSE input means that all input signals are referenced to a common ground
point that is also tied to the PCI-1200 analog input ground. The differential
amplifier negative input is tied to analog ground. The RSE configuration is
useful for measuring floating signal sources. With this input configuration,
the PCI-1200 can monitor eight different analog input channels.
Considerations for using the RSE configuration are discussed in Chapter 3,
Signal Connections . Notice that in this mode, the signal return path is
analog ground at the connector through the AISENSE/AIGND pin.
NRSE Input (Eight Channels)
NRSE input means that all input signals are referenced to the same
common-mode voltage, which floats with respect to the PCI-1200 analog
ground. This common-mode voltage is subsequently subtracted by the
input instrumentation amplifier. The NRSE configuration is useful for
measuring ground-referenced signal sources.
Table 2-2. Analog Input Modes for the PCI-1200
Analog Input
Modes Description
RSE RSE mode provides eight single-ended inputs with
the negative input of the instrumentation amplifier
referenced to analog ground (reset condition).
NRSE NRSE mode provides eight single-ended inputs with
the negative input of the instrumentation amplifier
tied to AISENSE/AIGND and not connected to
ground.
DIFF DIFF mode provides four differential inputs with the
positive input of the instrumentation amplifier tied to
channels 0, 2, 4, or 6 and the negative input tied to
channels 1, 3, 5, or 7, respectively, thus choosing
channel pairs (0, 1), (2, 3), (4, 5), or (6, 7).