David S Madden

US Patent:

6393493, May 21, 2002

Filed:

Apr 20, 1998

Appl. No.:

09/062893

Inventors:

David Madden - Austin TX
Mike Steed - Round Rock TX
Irwan Djajadi - Austin TX

Assignee:

National Instruments Corporation - Austin TX

International Classification:

G06F 954

US Classification:

709321, 710 23

Abstract:

A USB-based data acquisition system including virtual buffer software which increases USB data transfer rates with minimal changes to DAQ driver level software. The virtual buffer software operates to receive or intercept calls made by the DAQ driver level software to acquire data from the device, wherein the DAQ driver level software is designed to read the data from the device one sample at a time from the device. The virtual buffer software intercepts the call and requests the data in bulk packets from the device. The virtual buffer software then stores the received packets of data in a virtual buffer or virtual FIFO maintained in computer system memory. The DAQ driver level software then obtains the data from the computer system memory using much faster transfers. The virtual buffer software emulates operation of the device, including generation of interrupts and responses to status register reads, thus âfoolingâ the DAQ driver level software into thinking the data is being acquired from the device. Thus, the present invention allows for much faster data transfers, while requiring minimal or no changes to the existing DAQ driver level software.

US Patent:

6412028, Jun 25, 2002

Filed:

Apr 6, 1999

Appl. No.:

09/286701

Inventors:

Michael R. Steed - Round Rock TX
David W. Madden - Austin TX

Assignee:

National Instruments Corporation - Austin TX

International Classification:

G06F 1314

US Classification:

710 22, 710 15, 710 23, 710308, 709301, 702127

Abstract:

A USB-based data acquisition system including virtual DMA software which increases USB data transfer rates with minimal changes to DAQ driver level software. The virtual DMA software operates to receive or intercept DMA instructions provided by the DAQ driver level software to program a DMA controller to acquire data from the device. The virtual DMA software intercepts the DMA instructions and emulates operation of the DMA controller in software. The virtual DMA software operates to request the data in bulk packets from the device. The virtual DMA software then stores the received packets of data in the addresses specified in the DMA instructions. The virtual DMA software thus emulates operation of a DMA device, thus âfoolingâ the DAQ driver level software into thinking the data is being acquired using real DMA transfers. Thus, the present invention allows for much faster data transfers, while requiring minimal or no changes to the existing DAQ driver level software.

US Patent:

6640312, Oct 28, 2003

Filed:

Aug 1, 2000

Appl. No.:

09/629349

Inventors:

Andrew Thomson - Austin TX
David W. Madden - Austin TX
Glen Sescila - Pflugerville TX
Aljosa Vrancic - Austin TX

Assignee:

National Instruments Corporation - Austin TX

International Classification:

G06F 1100

US Classification:

714 5, 714 9, 714 43

Abstract:

A system and method for transferring data over a communications medium. A host is coupled to a device through a serial bus lacking error handling capabilities, such as an IEEE 1394 bus. The host may control the device by sending requests accessing its memory registers. The host generates a first request to the device to access a memory address location of the device, and which includes an address and status information indicating whether a prior request to the memory address location returned successfully. The device examines the status information to determine if it is a retry of a prior request, and if so, determines if the prior request completed successfully to the memory address location by comparing the address and data transfer size of the first request to those of the prior request. If identical, then the prior request completed successfully to the memory address location, and the request is ignored. Otherwise, the device retries the prior request.

US Patent:

6839777, Jan 4, 2005

Filed:

Sep 11, 2000

Appl. No.:

09/659914

Inventors:

Aljosa Vrancic - Austin TX, US
David W. Madden - Austin TX, US

Assignee:

National Instruments Corporation - Austin TX

International Classification:

G06F 300

US Classification:

710 52, 710 8, 710 22

Abstract:

A system and method for transferring data over a communications medium using data transfer links. A host computer may couple to a device through a serial bus. A buffer of contiguous virtual memory addresses may correspond to non-contiguous physical addresses, which may be stored in a linked list of transfer nodes, preserving the order of the original virtual buffer elements. Each transfer node specifies a data transfer between the host and device, and may be executed by the device DMA Controller. Each node may contain source and/or destination address information, size of the data to be transferred, and a link to the next node. The transfer nodes may be transferred to the device using a double-buffering scheme wherein the device executes the nodes from one half of the link buffer while the host computer transfers further nodes to be executed to the other half of the link buffer. The buffer halves may be switched back and forth between these two processes until all links are executed. To prevent overruns, safety and message links may be inserted into the transfer link list.

US Patent:

7043565, May 9, 2006

Filed:

Aug 11, 2000

Appl. No.:

09/638051

Inventors:

David W. Madden - Austin TX, US
Aljosa Vrancic - Austin TX, US

Assignee:

National Instruments Corporation - Austin TX

International Classification:

G06F 15/16

US Classification:

709250, 709217, 709236, 709230, 709231, 710 6, 710 33, 710 35, 719310, 719316, 719321, 718100

Abstract:

A system and method for transferring data over an external transmission medium. A host computer is coupled to a device through a serial bus. A transfer object is configurable to encapsulate data transfer-related functionality, providing a generic interface for transmission of data over a variety of external transmission media and protocols. A user makes one or more transfer requests. Transfer objects corresponding to each request are built and linked together to form a sequential chain. The requests of the transfer objects are executed sequentially. If the current transfer object is the first in the chain, the request is executed on a current thread at passive level or higher, otherwise the request is executed on a system (kernel) thread at dispatch level. When a response to the request returns, control is returned to the current transfer object. The process is repeated until all transfer objects are processed.

US Patent:

20170148304, May 25, 2017

Filed:

Feb 6, 2017

Appl. No.:

15/425131

Inventors:

Cynthia K. WALLACE - Tampa FL, US
David H. MADDEN - Portland OR, US

Assignee:

Strategic Healthcare Innovations, Inc. - Portland OR

International Classification:

G08B 21/24
G06F 19/00

Abstract:

Embodiments of the invention track users' hand-cleaning compliance and display an indication of each user's compliance so that others can estimate how well each user complies with policy guidelines. Making sanitation compliance visible in this way enables social pressure to be focused on negligent users without requiring others to take specific, individual actions to call out a negligent user. Other features of the system are also described and claimed.