National Instruments Corporation

Rafael Castro

Brian Keith Odom

Kyle R Bryson

Jeffrey J Kellam

Sean M Nickel

Andrew B Moch

Haider Ali Khan

One or more counter units of a data acquisition device used to perform sampling operations. Each of the counter units is configurable to operate in a selected one of a plurality of modes. During operation, at least one of the counter units may receive a measurement signal (or input signal) acquired by the data acquisition device and also a sample clock signal. The counter unit may sample the measurement signal based on the selected operational mode and timing of the sample clock, and at a rate that is independent of the frequency of the measurement signal. Furthermore, the counter unit may sample the measurement signal based on a selected one of a plurality of timing modes associated with the sample clock signal. The counter units may take samples of the measurement signal to perform at least one of the following types of measurements: period, frequency, pulse-width, semi-period, time separation, or event counting.

Sampling mechanism for data acquisition counters

A protection circuit for protecting a device from destructive electrical conditions, such as ESD, over-voltage, and over-current, while keeping the output impedance of the device's I/O lines to a minimum, and self-regulating power dissipation. The device may comprise a first protection circuit and a second protection circuit coupled to each of one or more I/O lines for providing a primary and a secondary level of protection, respectively, for the I/O lines. The first protection circuit of the device may combine the use of Schottky diodes for voltage clamping, with a current limiting device for self-regulating the power dissipation. The current limiting device may be operable to function as a small, low impedance resistor in a normal operating range and as a controlled power dissipater outside the normal operating range. The device may be a data acquisition device comprised in a data acquisition system.

Protection circuit for general-purpose digital I/O lines

An isolated data acquisition device including a plurality of data acquisition channels, an isolated system management unit coupled to the data acquisition channels, a host system management unit, a serial bus coupled to the host system management unit and the isolated system management unit, and isolation circuitry coupled to the serial bus. The isolation circuitry electrically isolates the host system management unit from the isolated system management unit and the data acquisition channels. During operation, the isolated system management unit and the host system management unit may each store data associated with one or more pending bus transactions. Each of the system management units may select at least one of the pending bus transactions according to a predetermined priority scheme, encode and serialize the data associated with the selected bus transaction, and transmit the serialized data across the isolation circuitry to the other system management unit via the serial bus.

High speed bus for isolated data acquisition applications

System and method for controlling cartridges to perform industrial operation(s). The system may include cartridge controllers coupled to the cartridges, timing and data routing logic coupled to the cartridge controllers, and controlling software coupled to the timing and data routing logic. Each of the cartridge controllers may be operable to detect and establish communications with a respective cartridge based on information retrieved from the cartridge, and adapt input/output signals of the respective cartridge according to instructions specified by the timing and data routing logic. The timing and data routing logic may be operable to synthesize data stream(s) from the adapted input/output signals, wherein each of the data stream(s) includes a respective subset of the adapted input/output signals received from a corresponding subset of the cartridges, and transmit the data stream(s) to the controlling software. The synthesized data stream(s) may appear as corresponding device(s) to the controlling software.

Generating a data stream from cartridge controllers using a plurality of measurement cartridges

Adapting a plurality of measurement cartridges using cartridge controllers

A flexible converter interface for interfacing with ADCs or DACs. The flexible converter interface may be comprised in a data acquisition device and may be a programmable ADC interface or a programmable DAC interface. The flexible converter interface may be programmed with a converter type parameter, a converter resolution parameter, and a converter data type parameter, among others, to interface with various types of ADCs or DACs and to allow for future expandability. The flexible converter interface may function as either a programmable parallel converter interface or a programmable serial converter interface depending upon the programmed converter type parameter. Additionally, functions associated with I/O pins corresponding to the flexible converter interface may vary depending upon the programmed converter resolution parameter and the programmed converter type parameter. Furthermore, the flexible converter interface may perform a data conversion operation on ADC or DAC data depending upon the programmed converter data type parameter.

Flexible converter interface for use in analog-to-digital and digital-to-analog systems

A system and method for buffering bidirectional digital input/output (I/O) lines. The system (e.g., data acquisition system) may comprise a device including circuitry for buffering bidirectional digital lines. A first integrated circuit (IC) of the device includes a first and a second bidirectional buffer coupled to a first bidirectional digital I/O line, and a second IC of the device includes a third bidirectional buffer. The first IC and the second IC each include a control unit to control the driving direction of the corresponding bidirectional buffers independently to change the direction of the data flow through the first bidirectional digital I/O line from the output direction to the input direction or vice versa. The driving direction of the bidirectional buffers are changed at different times in a particular sequence, and the order depends on whether the direction change is from the output direction to the input direction or vice versa.

Method of buffering bidirectional digital I/O lines

A measurement and data acquisition system including a real-time monitoring circuit for implementing control loop applications. The system control loop may include the real-time monitoring circuit, a data acquisition device, a processing unit, and a plurality of subsystems. The subsystems may be comprised in the data acquisition device or may be external to the data acquisition device. The real-time monitoring circuit may receive a plurality of timing signals from the plurality of subsystems and may select a control loop timing signal out of the plurality of timing signals. The real-time monitoring circuit may determine whether the operations of the control loop are performed within a particular period of time by monitoring the control loop timing signal and communicating with the processing unit. In response to an error notification, the processing unit may take appropriate action, such as shutting down the system and/or reporting an error or warning.

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Round Rock, TX, United States of America

Rafael Castro