National Instruments 8-Channel, 24 V Logic, Sinking Digital Input Device - Manuals

© National Instruments Corporation 5 NI USB-9421 User Guide and Specifications • Taking Measurements —Contains the conceptual and how-to information you need to acquire and analyze measurement data in LabVIEW, including common measurements, measurement fundamentals, NI-DAQmx key concepts, and device...

NI USB-9421 User Guide and Specifications 6 ni.com ANSI C without NI Application Software The NI-DAQmx Help contains API overviews and general information about measurement concepts. Select Start»All Programs»National Instruments»NI-DAQ»NI-DAQmx Help . The NI-DAQmx C Reference Help describes the NI-...

© National Instruments Corporation 7 NI USB-9421 User Guide and Specifications Training Courses If you need more help getting started developing an application with NI products, NI offers training courses. To enroll in a course or obtain a detailed course outline, refer to ni.com/training . Technica...

© National Instruments Corporation 9 NI USB-9421 User Guide and Specifications Mounting the NI USB-9421 to a Panel Threaded inserts are located in the NI USB-9421 for mounting it to a panel. Refer to Figure 6 for dimensions. Figure 6. Module Dimensions in Millimeters (Inches) Connecting the NI USB-9...

NI USB-9421 User Guide and Specifications 10 ni.com Wiring the NI USB-9421 Device Caution A high voltage screw terminal backshell must be installed when using hazardous voltages (>42.4 V pk , 60 VDC). Note Table 2 illustrates the accessories available from ni.com for use with the NI USB-9421. Tab...

© National Instruments Corporation 11 NI USB-9421 User Guide and Specifications Each channel of the NI USB-9421 has a terminal or pin, DI, to which you can connect voltage or current signals. The NI USB-9421 also has a common terminal or pin, COM, that is internally connected to the isolated referen...

NI USB-9421 User Guide and Specifications 12 ni.com Figure 7. Pin Assignments Connecting Devices to the NI USB-9421 The NI USB-9421 has sinking inputs , meaning that when current goes through or voltage is applied to the DI terminal or pin, DI provides a path to ground for the current or voltage. Th...

© National Instruments Corporation 13 NI USB-9421 User Guide and Specifications Figure 8. Connecting a Device to the NI USB-9421 (3-Wire Device Shown) The NI USB-9421 channel registers as ON when the sourcing-output device applies a voltage or drives a current to DI that is in the input ON range. Th...

NI USB-9421 User Guide and Specifications 14 ni.com Figure 10. Assembled High Voltage Screw Terminal Backshell Specifications The following specifications are typical for the range 0 to 60 °C unless otherwise noted. All voltages are relative to COM unless otherwise noted. Input Characteristics Numbe...

© National Instruments Corporation 15 NI USB-9421 User Guide and Specifications Bus Interface USB specification .................................. USB 2.0 Hi-Speed Physical Characteristics Dimensions With screw terminal ........................ 14.0 cm × 8.8 cm × 2.5 cm (5.52 in. × 3.47 in. × 1.00 i...

NI USB-9421 User Guide and Specifications 16 ni.com NI USB-9421 with D-SUB Safety Voltages Channel-to-COM ....................................30 V max Isolation Channel-to-channel..........................No isolation between channels Channel-to-earth ground Withstand ..................................

© National Instruments Corporation 17 NI USB-9421 User Guide and Specifications Operating humidity(IEC 60068-2-56) ................................... 10 to 90% RH, noncondensing Storage humidity(IEC 60068-2-56) ................................... 5 to 95% RH, noncondensing Maximum altitude ...........

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