National Instruments NI-9242 Analog Input Module

The National Instruments NI-9242 is a C Series analog input module designed for high-precision voltage measurements. With four differential channels and a ±10V input range, this module delivers 24-bit resolution and simultaneous sampling at rates up to 50 kS/s per channel. It is optimized for industrial data acquisition, condition monitoring, and general-purpose measurement tasks in CompactRIO and CompactDAQ systems.

Technical Specifications

Each channel features a programmable gain amplifier (PGA) with gains of 1, 2, 5, 10, and 20. The input impedance is 1 GΩ (in parallel with 47 pF), minimizing loading on high-impedance sensors. The module includes a built-in anti-aliasing filter and supports 50/60 Hz noise rejection (typical 60 dB at 50 Hz). Accuracy: ±0.05% of reading ±1.5 mV offset at 25°C. The -3 dB bandwidth is 24.5 kHz (typical). Operating temperature: -40°C to +70°C.

The NI-9242 connects via a 10-pin spring-terminal or screw-terminal connector (included accessories). It draws 650 mW from the chassis power supply. Overvoltage protection up to ±30 V is provided. The module meets IEC 61010-1 safety standards and is rated for Pollution Degree 2 environments.

Key Features

• 4 simultaneous sampling differential channels

• ±10 V input range, 24-bit ADC

• Maximum sampling rate: 50 kS/s per channel

• Programmable gain: 1,2,5,10,20

• High impedance input (1 GΩ)

• Embedded 50/60 Hz rejection filtering

• Hot-swappable with system identification (NICRIO)

• Compatible with LabVIEW, FlexLogger, and DAQExpress

Software Integration

The NI-9242 is fully supported by NI-DAQmx driver, providing access to advanced timing, triggering, and scaling functions. In LabVIEW Real-Time and LabVIEW FPGA (when used with CompactRIO), users can implement custom filtering, peak detection, or closed-loop control loops using the raw ADC data. The module also supports hardware-timed single-point (HWTSP) mode for fast control applications.

Typical Applications

Engineers use the NI-9242 for battery voltage monitoring, strain gauge measurements (with external bridge completion), accelerometer signal conditioning, and general laboratory measurements. In industrial environments, it serves for predictive maintenance (vibration sensors), power quality monitoring (transducer outputs), and process variable logging from 0-10V transmitters.

Chassis Compatibility

The module operates in any C Series chassis, including CompactRIO (cRIO-904x, cRIO-905x), CompactDAQ (cDAQ-917x, cDAQ-918x), and single-slot USB carriers (cDAQ-9171). Up to 16 modules can be installed in a 4-slot chassis, providing up to 64 analog input channels. The NI-9242 automatically synchronizes sampling across modules when installed in the same chassis.

Environmental and Certifications

This module is rated for industrial temperature range (-40°C to 70°C) with 10-55 Hz vibration (5g peak) and 50g shock. It carries CE, FCC, RoHS, and UKCA markings. The module is also certified for hazardous locations (Class I, Division 2, Groups A-D) with appropriate chassis. IP40 protection is provided for the front panel.

Conclusion

The National Instruments NI-9242 analog input module combines high resolution, simultaneous sampling, and rugged design, making it ideal for both lab-grade measurements and harsh industrial environments. Its seamless software integration and wide chassis compatibility reduce development time for engineers building data acquisition or control systems. For applications requiring ±10V inputs with 24-bit precision, the NI-9242 delivers reliable results.