Product Overview
The National Instruments PXI-6115 is a multifunction data acquisition module for PXI systems. It provides two analog input channels with 12 bit resolution and simultaneous sampling at up to 10 MS/s. The module also includes two analog output channels and digital input and output lines. It is designed for fast, correlated measurement of two signals in applications such as power measurement, stimulus response testing, and transient capture.
The PXI-6115 is part of the NI PXI platform, which provides high bandwidth backplane communication and timing synchronization. Because the module is installed in a PXI chassis, it can be synchronized with other instruments and controlled from the same application as switches, signal generators, and DMMs.
Simultaneous Analog Input
The two analog input channels sample at the same time, which preserves the phase relationship between signals. This is essential when computing power, phase angle, or transfer functions from two measured signals. Sequential sampling would introduce a timing offset that must be corrected mathematically, whereas simultaneous sampling avoids that error at the source.
The 12 bit resolution and high sampling rate support capture of fast transients and higher frequency content. Selectable input ranges allow the module to be matched to the signal levels in the application. Engineers should apply good probing and grounding practice to preserve signal integrity at high sampling rates.
Analog Output and Digital I/O
The module includes two analog output channels for generating control voltages, setpoints, and waveforms. Hardware timed output supports repeatable waveform generation, which is useful for stimulus response testing and control loop evaluation. Engineers should verify the load and settling requirements of the driven device.
Digital input and output lines provide logic level control and status monitoring. The module can use these lines for triggering, handshaking, or simple device control in a test sequence. The combination of analog and digital functions allows the module to handle mixed signal tasks in one PXI slot.
Timing and PXI Integration
NI-DAQmx provides trigger and clock configuration for the PXI-6115. Start triggers, reference triggers, and sample clocks allow acquisition to be aligned with external events. Within a PXI chassis, the module can share trigger lines and clocks with other instruments, enabling coordinated multi instrument test sequences.
Engineers should document the clock source and trigger routing so that the test sequence can be reproduced. For systems that require more channels, additional modules or devices can be synchronized where the architecture supports shared timing and triggering.
Software and Accessories
The PXI-6115 is supported by NI-DAQmx and can be programmed with LabVIEW, LabWindows/CVI, Measurement Studio, and other NI-DAQmx compatible environments. The driver handles channel configuration, scaling, calibration metadata, and task management. Signal conditioning accessories and shielded cables are available to connect signals to the module.
Installation requires a compatible PXI slot with adequate airflow and a chassis within the supported specifications. Cables should be routed away from power switching equipment, and shields should be terminated according to the accessory documentation. Regular verification of channel function and calibration supports long term measurement confidence.
Typical Applications
Power measurement with simultaneous voltage and current capture
Stimulus response testing of electronic circuits
Transient and fast signal capture
Phase and transfer function measurement
Control loop evaluation
PXI based test and measurement systems
The PXI-6115 provides two simultaneous analog inputs at up to 10 MS/s, two analog outputs, and digital I/O in a PXI module. Its simultaneous sampling and PXI integration make it suitable for fast two channel measurement applications.
