National Instruments Corporation

Audrey F Harvey

Joseph E Peck

James J Truchard

Kosta Ilic

Deborah E Bryant

Jaffar Shah

A counter circuit with multiple registers for eliminating reprogramming delays and for providing seamless switching between timing signals. In a first embodiment, two registers are preloaded with values and control logic chooses between the registers for loading a counter. The counter asserts a terminal count signal to output logic, which correspondingly asserts a convert pulse to an analog measuring circuit. The control logic receives start and stop signals and the terminal count signal, where the control logic controls operation accordingly. In this manner, a delay value is initially loaded into the counter to provide an initial delay period upon receiving the start signal, and then a scan rate value is continually loaded into the counter from another register thereafter for defining the scan rate until the start signal is received. Alternatively, first and second scan rate values are preloaded into the first and second registers, respectively, and a select signal is used as a gate signal to identify which of the scan rates to use. In this manner, the scan rate is almost immediately switched to the new rate when the gate signal is toggled to achieve seamless switching. In an alternative embodiment, multiple banks of dual registers and appropriate control and select logic define a different timing signal per register bank. In each bank the two registers define the low and high durations of the respective timing signals. Thus, the frequency and duty cycle of each timing signal is fully preprogrammed and switching from one timing signal to another occurs seamlessly without delay.

Counter circuit with multiple registers for seamless signal switching

A data acquisition configuration system and method for facilitating the creation of data acquisition applications. The present invention enables the user to create channel configurations which include information for a respective DAQ hardware channel, such as the physical phenomena being measured and how the phenomena is being measured. The user then assigns a name to each respective channel configuration. This channel configuration name is then usable in a data acquisition application to specify the channel configuration, thus simplifying application development. After specifying a channel configuration and assigning a name, the user then constructs a program which controls the data acquisition system. The program construction includes providing the assigned name which specifies the channel configuration for the selected channel of the data acquisition device. The program can then be executed to perform a data acquisition operation, wherein the executing includes using the channel configuration referenced by the assigned name in performing the data acquisition operation. The user is thus not required to create code to specify the channel configuration. Further, the program can execute in units of the physical quantity being measured/generated according to the channel configuration, and the user is not required to create code to operate in the units of the physical quantity being measured/generated.

DAQ configuration system and method for configuring channels in a data

An apparatus is provided for use in conjunction with a control system which can provide one or more respective output instructions and one or more corresponding respective timing instructions, the apparatus comprising a counter for providing a count sequence for substantially continuously providing a measure of elapsed time within a prescribed time interval; a storage device, responsive to a match indication, for storing multiple respective output instructions and corresponding multiple respective timing instructions and for asserting respective output instructions and corresponding respective timing instructions in order of a sequence such that upon receipt of a match indication, a next respective output instruction and a corresponding next respective timing instruction in the sequence are asserted; and a comparator for comparing each respective asserted timing instruction to the count of the count sequence and for providing the match indication upon an occurrence of a match.

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Austin, TX, United States of America

Audrey F Harvey