National Instruments BNC-2120 Installation Manual

Also see for BNC-2120: Installation guide

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National Instruments BNC-2120 Installation Manual Manual pdf 5 page image

© National Instruments Corporation 5 BNC-2120 Installation Guide5. Test specific device functionality, such as the ability to send and receive data with MAX test panels.Refer to the DAQ Getting Started Guide for detailed information about running test panels inMAX.When you have finished using the BNC-2120, power off any external signals connected to theBNC-2120 before you power off your computer.Connecting Analog Input SignalsYou can use the analog input BNCs on the BNC-2120 in the following ways:• Measure differential AI signals, as described in the Connecting Differential Analog Input Signalssection• Measure temperature, as described in the Measuring Temperature section• Measure resistance, as described in the Measuring Resistance sectionConnecting Differential Analog Input SignalsUse the BNC-2120 BNC connectors on the front panel to connect AI <0..7> signals to your DAQ device.The BNC-2120 is only intended for differential analog input signals. The number of connectors you usedepends on your DAQ device and application. Complete the following steps to measure a differential(DIFF) analog input signal.1. Connect the BNC cable to one of the AI <0..7> BNC connectors on the front panel. 12. If you are using AI 0, move the BNC/Temp. Ref. switch to the BNC position.If you are using AI 1, move the BNC/Thermocouple switch to the BNC position.If you are using AI 3, move the RES/BNC switch to the BNC position.3. Configure your software to measure the channel differentially.4. Move the FS/GS switch to the applicable position, depending on whether you are measuring afloating source (FS) or ground-referenced source (GS) analog input signal. Refer to the MeasuringFloating Signals and Measuring Ground-Referenced Signals sections for more information aboutthese signal sources.Measuring Floating SignalsTo measure floating signal sources, move the corresponding switch below the BNC connector to the FSposition. In the floating source switch position, the DAQ device’s amplifier negative terminal connectsto ground through a 4.99 kΩ resistor, as shown in Figure 2. Refer to your DAQ device documentationfor more information about measuring floating signals.1 When using the BNC-2120 with Connector 1 of NI 6224/6229/6254/6259/6284/6289 devices, the AI <0..7> BNCs on theBNC-2120 map to the AI <16..23> channels on the M Series device.