Product Overview
The National Instruments PCI-6250 is a multifunction data acquisition device for PCI based computers. It belongs to the NI M Series DAQ family and provides 16 analog input channels with 16 bit resolution and a maximum single channel sampling rate of 1.25 MS/s. The device also includes two analog output channels, 24 digital input and output lines, and two counters.
The PCI-6250 is designed for automated test, laboratory measurement, production verification, and control applications. Its sampling rate supports dynamic signal capture and fast transient recording, while the analog output and digital functions allow mixed signal test in one PCI card. The device is supported by NI-DAQmx software for configuration and programming.
Analog Input Performance
The device provides 16 analog input channels with 16 bit resolution and a maximum single channel rate of 1.25 MS/s, with the aggregate rate shared across active channels. Selectable input ranges, including plus or minus 10 V, plus or minus 5 V, and plus or minus 1 V, allow the device to match different signal levels and use the available resolution effectively.
Hardware timed acquisition, external sample clocks, and triggering support repeatable measurement sequences. Multichannel scanning can be configured for single ended or differential connections depending on the accessory and wiring. Differential wiring is often preferred for low level signals and for rejecting common mode noise.
Analog Output and Digital I/O
The device includes two 16 bit analog output channels for control voltages, setpoints, and waveform generation. Hardware timed output produces deterministic waveform sequences, which is useful for stimulus response testing, actuator command profiles, and calibration signals. Engineers should confirm the load and settling requirements of the driven device.
Twenty four digital lines provide logic level control, relay driving through external conditioning, and status monitoring. Two 32 bit counters support event counting, frequency measurement, pulse generation, and encoder position tracking. Because analog and digital tasks can share timing signals, the device can implement coordinated mixed signal sequences.
Timing and Synchronization
NI-DAQmx provides start triggers, reference triggers, pause triggers, and sample clock configuration for the PCI-6250. These features allow acquisition and generation to be aligned with external events or with other DAQ devices. Counter outputs can be routed as triggers, and analog or digital events can gate tasks.
For larger systems, multiple devices can be synchronized using shared timing and trigger signals where supported. Engineers should document clock sources and trigger routes so that test sequences can be reproduced. Careful planning of channel mapping helps when analyzing data from many sensors.
Software and Accessories
The PCI-6250 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. Screw terminal and mass termination accessories are available for different wiring needs.
Installation requires a PCI slot with adequate airflow and a host computer 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
High speed analog data acquisition
Waveform generation and stimulus response test
Mixed signal automated test systems
Sensor measurement and voltage monitoring
Encoder position and frequency measurement
PCI based test and measurement systems
The PCI-6250 provides 16 analog inputs at 1.25 MS/s, 2 analog outputs, 24 digital lines, and 2 counters in an M Series PCI card. Its speed, mixed signal capability, and NI-DAQmx support make it suitable for demanding measurement and control applications.
