USER GUIDE AND SPECIFICATIONS NI USB-9234 4-Channel, ±5 V, 24-Bit Software-Selectable IEPE and AC/DC Analog Input Module This user guide describes how to use the National Instruments USB-9234 and includes device specifications and connector assignments. Introduction The NI USB-9234 consists of two components: an NI 9234 module and an NI USB-9162 carrier, as shown in Figure 1.
Dimensions Figure 2 shows the NI USB-9234 device dimensions. Hi-Speed USB Carrier NI USB-9162 140.66 mm (5.538 in.) 120.68 mm (4.751 in.) 138.30 mm (5.445 in.) 118.26 mm (4.656 in.) 88.12 mm (3.469 in.) 25.34 mm (0.998 in.) Figure 2. NI USB-9234 Device in Millimeters (Inches) Safety Guidelines Operate the NI USB-9234 only as described in this user guide.
Safety Guidelines for Hazardous Voltages If hazardous voltages are connected to the module, take the following precautions. A hazardous voltage is a voltage greater than 42.4 Vpk or 60 VDC to earth ground. Ensure that hazardous voltage wiring is performed only by qualified personnel adhering to local electrical standards. Caution Caution Do not mix hazardous voltage circuits and human-accessible circuits on the same module.
LabVIEW If you are a new user, use the Getting Started with LabVIEW manual to familiarize yourself with the LabVIEW graphical programming environment and the basic LabVIEW features you use to build data acquisition and instrument control applications. Open the Getting Started with LabVIEW manual by selecting Start»All Programs»National Instruments»LabVIEW»LabVIEW Manuals or by navigating to the labview\manuals directory and opening LV_Getting_Started.pdf.
Measurement Studio If you program your NI-DAQmx-supported device in Measurement Studio using Visual C++, Visual C#, or Visual Basic .NET, you can interactively create channels and tasks by launching the DAQ Assistant from MAX or from within Visual Studio .NET. You can generate the configuration code based on your task or channel in Measurement Studio. Refer to the DAQ Assistant Help for additional information about generating code.
.NET Languages without NI Application Software With the Microsoft .NET Framework version 1.1 or later, you can use NI-DAQmx to create applications using Visual C# and Visual Basic .NET without Measurement Studio. You need Microsoft Visual Studio .NET 2003 or Microsoft Visual Studio 2005 for the API documentation to be installed. The installed documentation contains the NI-DAQmx API overview, measurement tasks and concepts, and function reference. This help is fully integrated into the Visual Studio .
Installing the Software Software support for the NI USB-9234 for Windows Vista/XP/2000 is provided by NI-DAQmx. The DAQ Getting Started Guide, which you can download at ni.com/manuals, offers NI-DAQmx users step-by-step instructions for installing software and hardware, configuring channels and tasks, and getting started developing an application. Installing Other Software If you are using other software, refer to the installation instructions that accompany your software.
Align the I/O module with the carrier, as shown in Figure 3. eed S Sp N IU Hi- 3. B BC US 2 16 -9 arr ier Figure 3. Module Installation 4. Squeeze the latches and insert the NI 9234 module into the NI USB-9162 carrier. 5. Press firmly on the connector side of the NI 9234 module until the latches lock the module into place, as shown in Figure 4. Hi- Sp N I U S B -9 16 2 eed US BC arr ier Figure 4. Locking Module into Place NI USB-9234 User Guide and Specifications 8 ni.
Mounting the NI USB-9234 Threaded inserts are located in the NI USB-9234 for mounting it to a panel. Refer to Figure 5 for the module dimensions. 85.7 mm (3.37 in.) 72.2 mm (2.84 in.) Threaded Insert M3 x 0.5 8.5 mm (0.34 in.) Max Depth 76.1 mm (3.00 in.) Figure 5. Module Dimensions Connecting the NI USB-9234 to a Computer Plug one end of the USB cable into the NI USB-9234 and the other end into an available USB port on the computer.
LED Indicator The NI USB-9234 device has a green LED next to the USB connector. The LED indicator indicates device status, as listed in Table 1. When the device is connected to a USB port, the LED blinks steadily to indicate that the device is initialized and is receiving power from the connection. If your device is not blinking, make sure your computer has the latest version of NI-DAQmx installed on it, and that the computer is not in standby mode. Table 1.
Wiring the NI USB-9234 The NI USB-9234 has four BNC connectors that provide connections to four simultaneously sampled analog input channels. Each channel has a BNC connector to which you can connect a signal source. You can also enable excitation current on a per-channel basis to connect Integrated Electronic Piezoelectric (IEPE) sensors. The center pin of the connector, AI+, provides the DC signal connection.
Connecting Signal Sources to the NI USB-9234 You can connect ground-referenced or floating signal sensors to the NI USB-9234. To avoid picking up ground noise, use a floating connection. To further minimize ground noise, prevent the metal shells of the BNC connectors from touching each other, the modules, or the chassis.
NI USB-9234 Circuitry The NI USB-9234 analog input channels are referenced to chassis ground through a 50 Ω resistor. To minimize ground noise, make sure that the chassis ground is connected to earth ground. Each channel is protected from overvoltages. You can configure the NI USB-9234 for AC or DC coupling for each channel. You can turn the IEPE excitation current on or off in AC-coupled mode (in software). IEPE current is not available in DC-coupled mode.
The NI USB-9234 also has TEDS circuitry. For more information about TEDS, go to ni.com/info and enter rdteds. Understanding NI USB-9234 Filtering The NI USB-9234 uses a combination of analog and digital filtering to provide an accurate representation of in-band signals while rejecting out-of-band signals. The filters discriminate between signals based on the frequency range, or bandwidth, of the signal. The three important bandwidths to consider are the passband, the stopband, and the alias-free bandwidth.
Stopband The filter significantly attenuates all signals above the stopband frequency. The primary goal of the filter is to prevent aliasing. Therefore, the stopband frequency scales precisely with the data rate. The stopband rejection is the minimum amount of attenuation applied by the filter to all signals with frequencies within the stopband. Alias-Free Bandwidth Any signal that appears in the alias-free bandwidth of the NI USB-9234 is not an aliased artifact of signals at a higher frequency.
Specifications The following specifications are typical for the range 0 to 60 °C unless otherwise noted. Input Characteristics Number of channels................................4 analog input channels ADC resolution.......................................24 bits Type of ADC ..........................................Delta-Sigma (with analog prefiltering) Sampling mode .......................................Simultaneous Type of TEDS supported ........................IEEE.1451.
AC cutoff frequency response Gain (dB) 0.5 0.0 –0.5 –1.0 0 1 2 3 5 6 7 4 Frequency (Hz) 8 9 10 Input range ............................................. ±5 V AC voltage full-scale range Minimum ........................................ ±5 Vpk Typical ............................................ ±5.1 Vpk Maximum........................................ ±5.2 Vpk Common-mode voltage (AI– to earth ground) .............................
Overvoltage protection (with respect to chassis ground) For a signal source connected to AI+ and AI– ................................±30 V For a low-impedance source connected to AI+ and AI– ...............–6 to 30 V Input delay ..............................................3.2 ms + 38.4 fs Accuracy1 Percent of Reading (Gain Error) Percent of Range* (Offset Error) Calibrated max (–40 to 70 °C) 0.34%, ±0.03 dB ±0.14%, 7.1 mV Calibrated typ (25 °C ±5 °C) 0.05%, ±0.005 dB ±0.006%, 0.
Phase nonlinearity (fs = 51.2 kS/s) ................................ ±0.45° max Stopband Frequency........................................ 0.55 · fs Rejection ......................................... 100 dB Alias-free bandwidth.............................. 0.45 · fs Oversample rate ..................................... 64 · fs Crosstalk (1 kHz) ................................... –110 dB CMRR (fin ≤ 1 kHz) Minimum ........................................ 40 dB Typical .....................................
Power Requirements Current consumption from USB.............500 mA, max Suspend mode..................................2.5 mA, max Bus Interface USB specification ...................................USB 2.0 Hi-Speed Physical Characteristics Dimensions .............................................12.1 cm × 8.6 cm × 2.5 cm (4.75 in. × 3.37 in. × 0.99 in.) Weight ....................................................Approx. 250 g (8.8 oz) Safety If you need to clean the module, wipe it with a dry towel.
Safety Standards This product is designed to meet the requirements of the following standards of safety for electrical equipment for measurement, control, and laboratory use: • IEC 61010-1, EN-61010-1 • UL 61010-1, CSA 61010-1 Note For UL and other safety certifications, refer to the product label or visit ni.com/ certification, search by model number or product line, and click the appropriate link in the Certification column.
CE Compliance This product meets the essential requirements of applicable European Directives, as amended for CE marking, as follows: • 2006/95/EC; Low-Voltage Directive (safety) • 2004/108/EC; Electromagnetic Compatibility Directive (EMC) Refer to the Declaration of Conformity (DoC) for this product for any additional regulatory compliance information. To obtain the DoC for this product, visit ni.
Where to Go for Support The National Instruments Web site is your complete resource for technical support. At ni.com/support you have access to everything from troubleshooting and application development self-help resources to email and phone assistance from NI Application Engineers. National Instruments corporate headquarters is located at 11500 North Mopac Expressway, Austin, Texas, 78759-3504. National Instruments also has offices located around the world to help address your support needs.
