The National Instruments CompactDAQ or cDAQ models, such as the cDAQ-9171, cDAQ-9174, cDAQ-9178, and more belong to this family of data acquisition models. A CompactDAQ system is comprised of a chassis linked to a PC via USB or Ethernet, which is filled with at least one I/O module. The National Instruments CompactDAQ Chassis can be utilized with C Series I/O modules for a mixture of counter/timer measurements, digital I/O, as well as analog I/O. Additionally, National Instruments cDAQ Chassis provide numerous timing engines. This feature enables the user to run several hardware-timed actions at the same time with individual rates for analog input. These Chassis have carrying slot counts, anywhere from 1 to 14, enabling the user to choose a Chassis with the requirements for their application. The Bus Connectors for these models are either USB 2.0, USB 3.0, Ethernet, or Wi-Fi. Several of the National Instruments NI cDAQ Chassis also have a synchronization feature and/or a built-in trigger.
The M Series manufactured by National Instruments is comprised of Multifunction DAQ Devices, which have as many as 80 analog input channels, 48 maximum lines of digital input/output, as many as four analog output channels, as well as two counters. There are several types of devices included in the M Series National Instruments, including: low-cost, industrial, bus-powered, high-accuracy, and high-speed. The low-cost, high-speed, and bus-powered families are not compatible with signal conditioning. However, the industrial family is compatible with low-pass filter signal conditioning and the industrial family is compatible with isolation signal conditioning. The families in the M Series also have differing platforms. The low-cost instruments are on PXI, USB, and PCI platforms. The bus-powered devices are solely the USB platform. Next, the industrial devices are for the PCI and PXI platforms. The high-accuracy instruments are also for the PCI and PXI platforms. Lastly, the high-speed devices are on the PCI, USB, and PXI platforms.
The National Instruments E Series is a Legacy Series which includes PCI and PXI Multifunction DAQ Devices. The E Series National Instruments devices have as many as 64 analog input channels, two counters, eight or 32 lines of digital input/output, and a maximum of two analog output channels. The E Series devices can be calibrated internally or externally. The self-calibration or internal calibration alters the instrument relative to an extremely precise and steady internal reference on the device. Self-calibration is recommended when environmental settings vary greatly. Self-calibration can be initiated by utilizing the self-calibrate function or VI that comes with the driver software. On the other hand, external calibration alters the instrument relative to a traceable, extremely precise calibration standard. It is suggested to calibrate the instrument at a minimum for the duration specified in the E Series User Manual.