Chapter 2 Installation and ConfigurationDAQCard-1200 User Manual 2-4 © National Instruments CorporationAnalog Input ModeThe DAQCard-1200 has three different input modes—referencedsingle-ended (RSE), non-referenced single-ended (NRSE), and differential(DIFF). Single-ended configuration provides eight input channels. DIFFconfiguration provides four input channels. Table 2-2 describes theseconfigurations.While reading the following paragraphs, you may find it helpful to refer tothe Analog Input Signal Connections section of Chapter 3, SignalConnections, which contains diagrams showing the signal paths for thethree configurations. These three modes are software selectable.RSE Input (Eight Channels, Default Setting)RSE input means that all input signals are referenced to a common groundpoint that is also tied to the DAQCard-1200 analog input ground. The RSEconfiguration is useful for measuring floating signal sources. See the Typesof Signal Sources section of Chapter 3, Signal Connections, for moreinformation. With the RSE configuration, the DAQCard-1200 can monitoreight different analog input channels.Considerations for using the RSE configuration are discussed in Chapter 3,Signal Connections. Notice that in RSE mode, the return path of thesignal is through analog ground at the connector through theAISENSE/AIGND pin.Table 2-2. Analog Input Modes for the DAQCard-1200AnalogInput Modes DescriptionRSE Referenced single-ended mode provides eight single-ended inputs with thenegative input of the instrumentation amplifier referenced to AISENSE/AIGND,which is tied to ground through about 200 Ω resistance (default setting).NRSE Non-referenced single-ended configuration provides eight single-ended inputswith the negative input of the instrumentation amplifier tied to AISENSE/AIGNDand not connected to ground.DIFF Differential mode provides four differential inputs with the positive input of theinstrumentation amplifier tied to channels 0, 2, 4, or 6 and the negative input tiedto channels 1, 3, 5, or 7, respectively, thus pairing channels (0, 1), (2,3), (4,5), (6,7).
