Multi-protocol field device interface with automatic bus detection

Information

  • Patent Grant
  • 8112565
  • Patent Number
    8,112,565
  • Date Filed
    Tuesday, June 6, 2006
    18 years ago
  • Date Issued
    Tuesday, February 7, 2012
    12 years ago
Abstract
A multi-protocol interface for coupling a field device to a general purpose computer is disclosed. The interface includes measurement circuitry to perform a plurality of measurements on a connected process communication loop to determine a process communication loop type. Then, if the interface includes a protocol interface module that matches the detected loop type, the protocol interface module can be engaged. A method for coupling a field device to a general purpose computer is also provided. In one aspect, power from the general purpose computer is used to power the process communication loop, if the interface determines that the loop is not powered.
Description
BACKGROUND OF THE INVENTION

Field devices are used in industries to control operation of a process such as an oil refinery. A field device, such as a transmitter, is typically part of a process communication loop and is located in the field to measure and transmit a process variable such as pressure, flow or temperature, for example, to control room equipment. A field device such as a valve controller can also be part of the process communication loop and controls position of a valve based upon a control signal received over the process control loop, or generated internally. Other types of controllers control electric motors or solenoids, for example. The control room equipment is also part of the process communication loop such that an operator or computer in the control room is capable of monitoring the process based upon process variables received from transmitters in the field and responsively controlling the process by sending control signals to the appropriate control devices. A process communication loop sometimes includes a portable communicator which is capable of monitoring and transmitting signals on the process communication loop. Typically, such portable communicators are used to configure field devices which form the process communication loop. As used herein, the term “process communications loop” is intended to mean any physical connection and media that carries process signals, regardless of whether the connection forms an actual loop. Thus, a process communication loop can be a HART® or FOUNDATION™ Fieldbus segment, even though such a segment is not strictly considered a loop.


With the advent of low-power microprocessors, field devices have undergone significant changes. Years ago, a field device would simply measure a given process variable, such as temperature, and generate an analog indication in the form of a current varying between 4 and 20 (mA) to indicate the measured temperature. Currently, many field devices employ digital communication technology as well as more sophisticated control and communication techniques. Field devices often employ low-power electronics because in many installations they are still required to run on as little as 4 mA. This design requirement prohibits the use of a number of commercially available microprocessor circuits. However, even low-power microprocessors have allowed a vast array of functions for such field devices.


There has been a dramatic increase in the availability of such microprocessor-based field devices. Such field devices are sometimes termed “smart” or “intelligent.” There has also been a dramatic increase in the availability of software applications that are used to configure, test, and diagnose these smart field devices. Connection of a general purpose computing device, such as a personal computer (PC) or a portable laptop computer is typically accomplished using a modem between the computing device and the intelligent field devices. There is a significant array of process communication protocols such as the HART®, FOUNDATION™ Fieldbus, Modbus®, and Profibus protocols that support the various process control tasks. Moreover, it is common to find multiple communication protocols in use in the very same process installation.


One technique for coupling a general purpose computing device to process communication networks having various process communication protocols is found in U.S. Pat. No. 6,839,790. The '790 patent reports an interface device that includes a re-configurable circuit which provides access to a selected fieldbus network from among several optional fieldbus networks. However, the techniques taught by the '790 patent generally require a user to have a priori knowledge of the particular type of fieldbus to which he or she is connecting. Thus, if a user wants to connect to a Profibus network, the user must make that selection known, and then the interface will reconfigure itself. However, if the user does not know what type of process communication protocol is being used, or if the user's selection is erroneous, the interface may begin communicating using a protocol that is not compatible with the actual protocol in use. This may introduce dangerous signaling levels that may damage, or otherwise degrade communication on the process control loop; damage or otherwise degrade the interface module itself, or potentially interfere with the proper operation of the process control loop.


SUMMARY OF THE INVENTION

A multi-protocol interface for coupling a field device to a general purpose computer is disclosed. The interface includes loop measurement circuitry to perform a plurality of measurements on a connected process communication loop to determine a process communication loop type. Then, if the interface includes a protocol interface module that matches the detected loop type, the protocol interface module can be engaged. A method for coupling a field device to a general purpose computer is also provided. In one aspect, power from the general purpose computer is used to power the process communication loop, if the interface determines that the loop is not powered.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is a diagrammatic view of a multi-protocol interface coupling a field device to a general purpose computing device in accordance with an embodiment of the present invention.



FIG. 2 is a block diagram of modem module 18 in accordance with embodiments of the present invention.



FIG. 3 is a flow diagram of a method of coupling a general purpose computer to a process communication loop using a multi-protocol process communication module in accordance with an embodiment of the present invention.



FIG. 4 is a flow diagram of a method of coupling a general purpose computer to a process communication loop in accordance with an embodiment of the present invention.





DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS


FIG. 1 is a diagrammatic view of a multi-protocol interface coupling a field device to a general purpose computing device in accordance with an embodiment of the present invention. Multi-protocol interface 10 couples field device 12 to general purpose computing device 14, which is illustrated as a laptop computer. The coupling between multi-protocol interface 10 and field device 12 may be effected via direct connection, such as via wiring terminals within the field device, or through process communication loop 16. Multi-protocol interface 10 includes network connection circuitry 18 that is configured to couple to process communication loops, and a connector module 20 that is configured to couple to general purpose computing device 14. Connector module 20 may include any suitable form of connector for connecting to computer 14. Suitable examples include, but are not limited to, universal serial bus (USB) connections, standard serial connections such as those that employ DB9 or DB25 connectors, parallel connections, PCMCIA connections, PCI connections, and firewire connections. In embodiments of the present invention where connector module 20 includes a wired connection to general purpose computing device 14, it is preferred that multi-protocol interface 10 be powered through the wired communication interface. Embodiments of the present invention can also be practiced where the data communication between multi-protocol interface module 10 and general purpose computing device 14 is a wireless connection. Examples of suitable wireless connections include infrared communication, Bluetooth communication, and WIFI communication (such as IEEE 802.11b or IEEE 802.11g). Further, as the art of general purpose computing devices advances, embodiments of the present invention can be practiced using any suitable data communication for which the general purpose computer is adapted, whether now known, or later developed.



FIG. 2 is a block diagram of network connection circuitry 18 in accordance with embodiments of the present invention. As illustrated, network connection circuitry 18 includes microprocessor 38 that is configured to couple, via line 46, to connector module 20 (show in FIG. 1). Circuitry 18 also includes analog-to-digital converter 36 which is coupled to microprocessor 38. Converter 36 is coupled to measurement circuitry 32 via control logic 34. Microprocessor 38 is also coupled to external data bus 40 through which it interacts with read only memory 42 and random access memory 44. Through data bus 40, microprocessor 38 is also able to interact with first protocol interface module 26 and a protocol interface module 28. Each of modules 26 and 28 is designed to communicate in accordance with a standard process communication protocol. For example, first protocol interface module 26 may be configured to communicate in accordance with the HART® protocol while second protocol interface module 28 is configured to communicate in accordance with the FOUNDATION™ Fieldbus protocol. Additionally, while FIG. 2 illustrates a pair of modules, embodiments of the present invention can be practiced by employing three or more such protocol interface modules. Each protocol interface module allows communication in accordance with its respective process communication protocol.


As described above, if the wrong type of protocol interface module communicates over a process communication loop, incompatible signal levels, data, interference, or other undesirable effects can diminish the communication capabilities of the process communication network, or even damage the associated devices. In accordance with an embodiment of the present invention, network connection circuitry 18 includes loop measurement circuitry 32. As illustrated in FIG. 2, module 18 includes a pair of terminals 50, 52 with each of terminals 50, 52 being coupled to each of protocol interface modules 26 and 28, and to loop measurement circuitry 32. Utilization of loop measurement circuitry 32 allows network connection circuitry 18 to make various measurements to connected process communication loops, before engaging one of protocol interface modules 26 or 28.


The circuitry of multi-protocol interface 10 preferably facilitates compliance with intrinsic safety requirements. Compliance with intrinsic safety requirements means compliance with an intrinsic Safety specification such as one or more of the portions of the standard promulgated by Factory Mutual Research in October 1998, entitled APPROVAL STANDARD INTRINSICALLY SAFE APPARATUS AND ASSOCIATED APPARATUS FOR USE IN CLASS I, II AND III, DIVISION 1 HAZARDOUS (CLASSIFIED) LOCATIONS, CLASS NUMBER 3610.


When operating with a HART® process control loop, interface 10 must not sink or source a direct current (DC). To meet intrinsic safety requirements for FOUNDATION™ Fieldbus, interface 10 must not inject any energy into the process control loop. Because these two protocols have two fundamentally different (and conflicting) ways of communicating, the circuitry of interface 10 must never sink a current in a HART® process control loop nor inject energy (impose a voltage) in a FOUNDATION™ Fieldbus segment.


As illustrated in FIG. 2, network connection circuitry 18 includes loop measurement circuitry 32 that includes one or more individual measurement signal conditioning circuits. Preferably, circuitry 32 includes a circuit that can sink a small amplitude short duration current from the network. In another embodiment, circuitry 32 may include three or more individual measurement conditioning circuits that scale the voltage signal on the FOUNDATION™ Fieldbus network connector to measure DC voltage, communications signal amplitude, and network or loop noise. Measurement circuitry 32 may also include a measurement circuit that measures DC voltage on the network. These various signal conditioning circuits all feed control logic block 34. Control logic block 34 includes a multiplexer that is connected to analog-to-digital converter 36. Control logic block 34 is accessed by microprocessor 38 via bus 40. Although FIG. 2 illustrates the connection between microprocessor 38 and converter 36 separate from data bus 40, embodiments of the present invention can be practiced with converter 36 coupled to microprocessor 38 any suitable external bus including a Serial Peripheral Interface (SPI). When interface 10 is first turned on, or provided with power, microprocessor 38 commands analog-to-digital converter 36 to monitor the DC voltage on network connection terminals 50 and 52. During this state, interface 10 will not disturb the network (also referred to as process control loop) in any way (i.e., sink/source current or impose a voltage). If there are no network connections, the voltage measured will be near zero on the loop connection. When a process control loop is coupled to terminals 50 and 52, a DC voltage will be measured. A HART® process control loop will cause a voltage between approximately 12 and 50 volts DC to be measured while a FOUNDATION™ Fieldbus loop connection will cause a voltage between 9 and 32 volts DC to be measured. Once a DC voltage is recognized, the polarity is measured to determine whether the loop connection leads are correctly connected. Specifically, if the DC voltage measured between common lead 50 and lead 52 has a negative polarity, that means that the loop connection leads are reversed. Microprocessor 38 then preferably sends a message informing the user that the loop connection leads must be reversed. In one embodiment, when interface 10 determines that the polarity is reversed, interface 10 ensures that when a protocol interface module is later engaged, that it is engaged in such a way that the reversed polarity is automatically corrected using circuitry of the interface. This correction can be effected simply using switches that essentially reverse the terminals before entering each protocol interface unit. However, other forms of circuitry and/or approaches can be utilized to automatically correct the polarity.


As indicated above, there is an overlap between the operating DC voltages used on both HART® and FOUNDATION™ Fieldbus process communication loops. Therefore, DC voltage alone cannot be used to reliably indicate the type of loop to which device 10 is connected. To determine loop type, interface 10, using measurement circuitry 32 actually measures the DC impedance of the process control loop (preferably having a reasonable DC voltage and correct lead polarity). Interface 10 measures network DC impedance by sinking a small amount of current, for example, 1 mA, for a very short duration, such as 5 milliseconds, and then measuring the shape and amplitude of the resultant voltage pulse on the process communication loop. This disturbance generates a voltage pulse along the process control loop that is proportional to the DC impedance of the process control loop itself. There is a distinguishing range of impedance between HART® and FOUNDATION™ Fieldbus process control loops. The signal that interface 10 observes in response to the disturbance it generates also contains any HART® or FOUNDATION™ Fieldbus communication signals that may be present on the process control loop. The communication signals themselves are filtered using the suitable low pass filter so that only the effect of the short-duration pulse is observed by device 10. Analog-to-digital converter 36 measures the amplitude of the associated disturbance to determine the network type from this voltage measurement. A FOUNDATION™ Fieldbus network will have a computed impedance of approximately 50 ohms. A HART® network will have a computed impedance greater than approximately 125 ohms. If the network or process control loop type detected accords with one of protocol interface modules 26 or 28, then communications can proceed by engaging that respective protocol interface module.



FIG. 3 is a flow diagram of a method of coupling a general purpose computer to a process communication loop using a multi-protocol process communication module in accordance with an embodiment of the present invention. Method 100 begins at block 102 when the multi-protocol interface is first powered. This step may occur when the interface is first coupled to a general purpose computer and receives electrical operating energy from the computer, or simply when a user engages a switch or other suitable object on the interface module to turn the device on. Method 100 continues at block 104 where the multi-protocol interface monitors the voltage across its process communication terminals. This step continues until a non-zero voltage is observed across the process communication or loop terminals. Once this occurs, control passes to block 106 where the multi-protocol interface performs one or more loop-related measurements using loop measurement circuitry as described above. The loop-related measurements are performed until the type of process communication loop can be discerned, or until all available measurements are exhausted. FIG. 3 indicates optional block 108 that can be employed in accordance with embodiments of the present invention. Specifically, once loop-related measurement(s) are performed, a suggestion regarding the type of process communication loop can be automatically provided to the user. The user can then confirm the process communication selection and the associated media access unit will be engaged. Providing an automatic suggestion to a user is unlike allowing a user to simply select a media access unit. For example, if the user erroneously believes that he or she is interacting with a HART® process communication loop, but the multi-protocol interface reports, through its connection with general purpose computing device 14, that the loop-related measurements actually indicate a FOUNDATION™ Fieldbus loop, the user's options are to either acquiesce to the FOUNDATION™ Fieldbus suggestion, or to not engage interface 10 on the loop. Thus, the user's erroneous belief that the process communication loop is a HART® loop is kept from damaging or degrading the communications and/or devices. At block 110, the associated protocol interface module that corresponds to the loop-related measurements and optionally with the user's acknowledgment of the autosuggestion as indicated in block 108 is engaged.


Embodiments of the present invention generally include detection circuitry that automatically detects the communication protocol of a process communication loop. Additionally, embodiments of the present invention also preferably automatically detect parameters of the communication protocol in order to enable appropriate communications. Embodiments of the present invention generally advise users of incompatible protocols, and protect users from using the wrong communication protocol for the connected devices. For example, when connected to a powered HART® loop, the device automatically detects HART® protocol parameters, and automatically enables HART® communication between the general purpose computing device and the HART® field devices on the loop. When connected to a powered FOUNDATION™ Fieldbus segment, the device automatically detects FOUNDATION™ Fieldbus protocol parameters, and automatically enables FOUNDATION™ Fieldbus communication between the general purpose computing device and FOUNDATION™ Fieldbus field devices on the segment.



FIG. 4 is a flow diagram of a method of coupling a general purpose computer to a process communication loop in accordance with an embodiment of the present invention. Method 200 begins at block 202 when the interface is first powered. Block 202 can occur when the interface is first coupled to a general purpose computer, or when a user engages a switch on the interface. At block 204, the interface makes at least one measurement relative to the process communication terminals. Suitable measurements include attempting to detect a voltage, attempting to detect continuity between the process communication terminals, or any other suitable measurement. At block 206, the interface determines, using the results of the loop-related measurement(s), whether a process communication loop has been connected to the interface. If not, control returns to block 204, and the method continues waiting for a loop connection. However, if block 206 determines that a process communication loop has been coupled to the terminals of the interface, then control passes to block 208, where the interface determines if the loop is already powered. This step may be accomplished by using measurement circuitry, such as circuitry 32, to measure a voltage and/or impedance of the newly connected loop. If the newly connected loop is not powered, control passes to block 210 where the interface uses energy received from its connection to the general purpose computer (such as through a USB connection) to provide power to the process control loop. Once the interface has powered the process communication loop at block 210, control passes to block 212. If block 208 determines that the process communication loop is powered, control passes to block 212 from block 208. At block 212, measurement circuitry of the interface is again employed to make a plurality of measurements to determine the type of process control loop to which the interface is connected. Once sufficient measurements have been made, or if all measurements have been exhausted, control passes to block 214 where the protocol interface module that matches the detected loop type is engaged. If the detected loop type does not match any available protocol interface modules, then the interface will simply register an error, but will not engage an erroneous protocol interface module.


Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims
  • 1. A multi-protocol interface for coupling a field device to a general purpose computer, the interface comprising: a connector module wirelessly coupled to the general purpose computer;a plurality of process communication terminals coupled to a process communication loop;a first protocol interface module coupled to the plurality of process communication terminals and configured to communicate in accordance with a first protocol;a second protocol interface module coupled to the plurality of process communication terminals and configured to communicate in accordance with a second protocol different from the first protocol;loop measurement circuitry operably coupled to the process communication terminals; anda microprocessor coupled to the first and second protocol interface modules and coupled to the measurement circuitry, the microprocessor determining a process communication loop type based at least in part upon a plurality of loop-related measurements made by the measurement circuitry when a process communication loop is coupled to the process communication terminals; andwherein the multi-protocol interface is configured to provide a loop type suggestion to a user in accordance with the process communication loop type, and wherein a protocol interface module having a protocol that matches the determined process communication loop type is engaged for communication only if the user acquiesces to the suggestion.
  • 2. The interface of claim 1, wherein the wireless coupling is in accordance with Bluetooth communication.
  • 3. The interface of claim 1, wherein the wireless coupling is in accordance with WiFi communication.
  • 4. The interface of claim 1, wherein at least one of the loop-related measurements includes voltage across the process communication terminals.
  • 5. The interface of claim 4, wherein at least one of the loop-related measurements includes measurement of loop impedance.
  • 6. The interface of claim 1, wherein the interface is intrinsically safe.
  • 7. The interface of claim 1, wherein the microprocessor determines process communication loop type based at least in part upon a user's response to a loop type suggestion provided to the user.
CROSS-REFERENCE TO RELATED APPLICATION

The present application is based on and claims the benefit of U.S. provisional patent application Ser. No. 60/688,657, filed Jun. 8, 2005, the content of which is hereby incorporated by reference in its entirety.

US Referenced Citations (360)
Number Name Date Kind
3096434 King Jul 1963 A
3404264 Kugler Oct 1968 A
3468164 Sutherland Sep 1969 A
3590370 Fleischer Jun 1971 A
3618592 Stewart Nov 1971 A
3688190 Blum Aug 1972 A
3691842 Akeley Sep 1972 A
3701280 Stroman Oct 1972 A
3849637 Caruso et al. Nov 1974 A
3855858 Cushing Dec 1974 A
3948098 Richardson et al. Apr 1976 A
3952759 Ottenstein Apr 1976 A
3973184 Raber Aug 1976 A
RE29383 Gallatin et al. Sep 1977 E
4058975 Gilbert et al. Nov 1977 A
4083031 Pharo, Jr. Apr 1978 A
4099413 Ohte et al. Jul 1978 A
4102199 Talpouras Jul 1978 A
4122719 Carlson et al. Oct 1978 A
4249164 Tivy Feb 1981 A
4250490 Dahlke Feb 1981 A
4255964 Morison Mar 1981 A
4279013 Cameron et al. Jul 1981 A
4337516 Murphy et al. Jun 1982 A
4383443 Langdon May 1983 A
4399824 Davidson Aug 1983 A
4417312 Cronin et al. Nov 1983 A
4423634 Audenard et al. Jan 1984 A
4459858 Marsh Jul 1984 A
4463612 Thompson Aug 1984 A
4517468 Kemper et al. May 1985 A
4528869 Kubo et al. Jul 1985 A
4530234 Cullick et al. Jul 1985 A
4536753 Parker Aug 1985 A
4540468 Genco et al. Sep 1985 A
4571689 Hildebrand et al. Feb 1986 A
4630265 Sexton Dec 1986 A
4635214 Kasai et al. Jan 1987 A
4642782 Kemper et al. Feb 1987 A
4644479 Kemper et al. Feb 1987 A
4649515 Thompson et al. Mar 1987 A
4668473 Agarwal May 1987 A
4686638 Furuse Aug 1987 A
4696191 Claytor et al. Sep 1987 A
4707796 Calabro et al. Nov 1987 A
4720806 Schippers et al. Jan 1988 A
4736367 Wroblewski et al. Apr 1988 A
4736763 Britton et al. Apr 1988 A
4758308 Carr Jul 1988 A
4777585 Kokawa et al. Oct 1988 A
4807151 Citron Feb 1989 A
4818994 Orth et al. Apr 1989 A
4831564 Suga May 1989 A
4841286 Kummer Jun 1989 A
4853693 Eaton-Williams Aug 1989 A
4873655 Kondraske Oct 1989 A
4907167 Skeirik Mar 1990 A
4924418 Backman et al. May 1990 A
4926364 Brotherton May 1990 A
4934196 Romano Jun 1990 A
4939753 Olson Jul 1990 A
4964125 Kim Oct 1990 A
4988990 Warrior Jan 1991 A
4992965 Holter et al. Feb 1991 A
5005142 Lipchak et al. Apr 1991 A
5019760 Chu et al. May 1991 A
5025344 Maly et al. Jun 1991 A
5043862 Takahashi et al. Aug 1991 A
5047990 Gafos et al. Sep 1991 A
5053815 Wendell Oct 1991 A
5057774 Verhelst et al. Oct 1991 A
5067099 McCown et al. Nov 1991 A
5081598 Bellows et al. Jan 1992 A
5089979 McEachern et al. Feb 1992 A
5089984 Struger et al. Feb 1992 A
5098197 Shepard et al. Mar 1992 A
5099436 McCown et al. Mar 1992 A
5103409 Shimizu et al. Apr 1992 A
5111531 Grayson et al. May 1992 A
5121467 Skeirik Jun 1992 A
5122794 Warrior Jun 1992 A
5122976 Bellows et al. Jun 1992 A
5130936 Sheppard et al. Jul 1992 A
5134574 Beaverstock et al. Jul 1992 A
5137370 McCullock et al. Aug 1992 A
5142612 Skeirik Aug 1992 A
5143452 Maxedon et al. Sep 1992 A
5148378 Shibayama et al. Sep 1992 A
5150289 Badavas Sep 1992 A
5167009 Skeirik Nov 1992 A
5175678 Frerichs et al. Dec 1992 A
5193143 Kaemmerer et al. Mar 1993 A
5197114 Skeirik Mar 1993 A
5197328 Fitzgerald Mar 1993 A
5212765 Skeirik May 1993 A
5214582 Gray May 1993 A
5216226 Miyoshi Jun 1993 A
5224203 Skeirik Jun 1993 A
5228780 Shepard et al. Jul 1993 A
5235527 Ogawa et al. Aug 1993 A
5265031 Malczewski Nov 1993 A
5265222 Nishiya et al. Nov 1993 A
5269311 Kirchner et al. Dec 1993 A
5274572 O'Neill et al. Dec 1993 A
5282131 Rudd et al. Jan 1994 A
5282261 Skeirik Jan 1994 A
5293585 Morita Mar 1994 A
5303181 Stockton Apr 1994 A
5305230 Matsumoto et al. Apr 1994 A
5311421 Nomura et al. May 1994 A
5317520 Castle May 1994 A
5327357 Feinstein et al. Jul 1994 A
5333240 Matsumoto et al. Jul 1994 A
5340271 Freeman et al. Aug 1994 A
5347843 Orr et al. Sep 1994 A
5349541 Alexandro, Jr. et al. Sep 1994 A
5357449 Oh Oct 1994 A
5361628 Marko et al. Nov 1994 A
5365423 Chand Nov 1994 A
5365787 Hernandez et al. Nov 1994 A
5367612 Bozich et al. Nov 1994 A
5369674 Yokose et al. Nov 1994 A
5384699 Levy et al. Jan 1995 A
5386373 Keeler et al. Jan 1995 A
5388465 Okaniwa et al. Feb 1995 A
5392293 Hsue Feb 1995 A
5394341 Kepner Feb 1995 A
5394543 Hill et al. Feb 1995 A
5404064 Mermelstein et al. Apr 1995 A
5408406 Mathur et al. Apr 1995 A
5408586 Skeirik Apr 1995 A
5410495 Ramamurthi Apr 1995 A
5414645 Hirano May 1995 A
5419197 Ogi et al. May 1995 A
5430642 Nakajima et al. Jul 1995 A
5434774 Seberger Jul 1995 A
5436705 Raj Jul 1995 A
5440478 Fisher et al. Aug 1995 A
5442639 Crowder et al. Aug 1995 A
5467355 Umeda et al. Nov 1995 A
5469070 Koluvek Nov 1995 A
5469156 Kogure Nov 1995 A
5469735 Watanabe Nov 1995 A
5469749 Shimada et al. Nov 1995 A
5481199 Anderson et al. Jan 1996 A
5481200 Voegele et al. Jan 1996 A
5483387 Bauhahn et al. Jan 1996 A
5485753 Burns et al. Jan 1996 A
5486996 Samad et al. Jan 1996 A
5488697 Kaemmerer et al. Jan 1996 A
5489831 Harris Feb 1996 A
5495769 Broden et al. Mar 1996 A
5510779 Maltby et al. Apr 1996 A
5511004 Dubost et al. Apr 1996 A
5526293 Mozumder et al. Jun 1996 A
5539638 Keeler et al. Jul 1996 A
5548528 Keeler et al. Aug 1996 A
5555190 Derby et al. Sep 1996 A
5560246 Bottinger et al. Oct 1996 A
5561599 Lu Oct 1996 A
5570034 Needham et al. Oct 1996 A
5570300 Henry et al. Oct 1996 A
5572420 Lu Nov 1996 A
5573032 Lenz et al. Nov 1996 A
5578763 Spencer et al. Nov 1996 A
5591922 Segeral et al. Jan 1997 A
5598521 Kilgore et al. Jan 1997 A
5600148 Cole et al. Feb 1997 A
5608650 McClendon et al. Mar 1997 A
5623605 Keshav et al. Apr 1997 A
5629870 Farag et al. May 1997 A
5633809 Wissenbach et al. May 1997 A
5637802 Frick et al. Jun 1997 A
5640491 Bhat et al. Jun 1997 A
5644240 Brugger Jul 1997 A
5654869 Ohi et al. Aug 1997 A
5661668 Yemini et al. Aug 1997 A
5665899 Willcox Sep 1997 A
5669713 Schwartz et al. Sep 1997 A
5671335 Davis et al. Sep 1997 A
5671355 Collins Sep 1997 A
5672247 Pangalos et al. Sep 1997 A
5675504 Serodes et al. Oct 1997 A
5675724 Beal et al. Oct 1997 A
5680109 Lowe et al. Oct 1997 A
5682317 Keeler et al. Oct 1997 A
5682476 Tapperson et al. Oct 1997 A
5700090 Eryurek Dec 1997 A
5703575 Kirkpatrick Dec 1997 A
5704011 Hansen et al. Dec 1997 A
5705754 Keita et al. Jan 1998 A
5705978 Frick et al. Jan 1998 A
5708211 Jepson et al. Jan 1998 A
5708585 Kushion Jan 1998 A
5710370 Shanahan et al. Jan 1998 A
5710708 Wiegland Jan 1998 A
5713668 Lunghofer et al. Feb 1998 A
5719378 Jackson, Jr. et al. Feb 1998 A
5731522 Sittler Mar 1998 A
5736649 Kawasaki et al. Apr 1998 A
5741074 Wang et al. Apr 1998 A
5742845 Wagner Apr 1998 A
5746511 Eryurek et al. May 1998 A
5747701 Marsh et al. May 1998 A
5752008 Bowling May 1998 A
5764539 Rani Jun 1998 A
5764891 Warrior Jun 1998 A
5781024 Blomberg et al. Jul 1998 A
5781878 Mizoguchi et al. Jul 1998 A
5790413 Bartusiak et al. Aug 1998 A
5796006 Bellet et al. Aug 1998 A
5801689 Huntsman Sep 1998 A
5805442 Crater et al. Sep 1998 A
5817950 Wiklund et al. Oct 1998 A
5825664 Warrior et al. Oct 1998 A
5828567 Eryurek et al. Oct 1998 A
5829876 Schwartz et al. Nov 1998 A
5848383 Yuuns Dec 1998 A
5854993 Crichnik Dec 1998 A
5854994 Canada et al. Dec 1998 A
5859964 Wang et al. Jan 1999 A
5869772 Storer Feb 1999 A
5876122 Eryurek Mar 1999 A
5880376 Sai et al. Mar 1999 A
5887978 Lunghofer et al. Mar 1999 A
5908990 Cummings Jun 1999 A
5923557 Eidson Jul 1999 A
5924086 Mathur et al. Jul 1999 A
5926778 Pöppel Jul 1999 A
5934371 Bussear et al. Aug 1999 A
5936514 Anderson et al. Aug 1999 A
5938754 Edwards et al. Aug 1999 A
5940290 Dixon Aug 1999 A
5956663 Eryurek et al. Sep 1999 A
5970430 Burns et al. Oct 1999 A
5995910 Discenzo Nov 1999 A
6002952 Diab et al. Dec 1999 A
6006338 Longsdorf et al. Dec 1999 A
6014612 Larson et al. Jan 2000 A
6014902 Lewis et al. Jan 2000 A
6016523 Zimmerman et al. Jan 2000 A
6016706 Yamamoto et al. Jan 2000 A
6017143 Eryurek et al. Jan 2000 A
6023399 Kogure Feb 2000 A
6026352 Burns et al. Feb 2000 A
6038579 Sekine Mar 2000 A
6045260 Schwartz et al. Apr 2000 A
6046642 Brayton et al. Apr 2000 A
6047220 Eryurek et al. Apr 2000 A
6047222 Burns et al. Apr 2000 A
6052655 Kobayashi et al. Apr 2000 A
6061603 Papadopoulos et al. May 2000 A
6072150 Sheffer Jun 2000 A
6094600 Sharpe, Jr. et al. Jul 2000 A
6112131 Ghorashi et al. Aug 2000 A
6119047 Eryurek et al. Sep 2000 A
6119529 Di Marco et al. Sep 2000 A
6139180 Usher et al. Oct 2000 A
6151560 Jones Nov 2000 A
6179964 Begemann et al. Jan 2001 B1
6182501 Furuse et al. Feb 2001 B1
6192281 Brown et al. Feb 2001 B1
6195591 Nixon et al. Feb 2001 B1
6199018 Quist et al. Mar 2001 B1
6209048 Wolff Mar 2001 B1
6211649 Matsuda Apr 2001 B1
6236948 Eck et al. May 2001 B1
6237424 Salmasi et al. May 2001 B1
6260004 Hays et al. Jul 2001 B1
6263487 Stripf et al. Jul 2001 B1
6272438 Cunningham et al. Aug 2001 B1
6289735 Dister et al. Sep 2001 B1
6298377 Hartikainen et al. Oct 2001 B1
6307483 Westfield et al. Oct 2001 B1
6311136 Henry et al. Oct 2001 B1
6317701 Pyostsia et al. Nov 2001 B1
6327914 Dutton Dec 2001 B1
6347252 Behr et al. Feb 2002 B1
6356191 Kirkpatrick et al. Mar 2002 B1
6360277 Ruckley et al. Mar 2002 B1
6370448 Eryurek et al. Apr 2002 B1
6377859 Brown et al. Apr 2002 B1
6378364 Pelletier et al. Apr 2002 B1
6396426 Balard et al. May 2002 B1
6397114 Eryurek et al. May 2002 B1
6404393 Nelson et al. Jun 2002 B1
6405099 Nagai et al. Jun 2002 B1
6425038 Sprecher Jul 2002 B1
6434504 Eryurek et al. Aug 2002 B1
6449574 Eryurek et al. Sep 2002 B1
6473656 Langels et al. Oct 2002 B1
6473710 Eryurek Oct 2002 B1
6480793 Martin Nov 2002 B1
6492921 Kunitani et al. Dec 2002 B1
6493689 Kotoulas et al. Dec 2002 B2
6497222 Bolz et al. Dec 2002 B2
6505517 Eryurek et al. Jan 2003 B1
6519546 Eryurek et al. Feb 2003 B1
6532392 Eryurek et al. Mar 2003 B1
6539267 Eryurek et al. Mar 2003 B1
6546814 Choe et al. Apr 2003 B1
6556145 Kirkpatrick et al. Apr 2003 B1
6567006 Lander et al. May 2003 B1
6594603 Eryurek et al. Jul 2003 B1
6597997 Tingley Jul 2003 B2
6601005 Eryurek et al. Jul 2003 B1
6601124 Blair Jul 2003 B1
6611775 Coursolle et al. Aug 2003 B1
6615149 Wehrs Sep 2003 B1
6654697 Eryurek et al. Nov 2003 B1
6701274 Eryurek et al. Mar 2004 B1
6727812 Sauler et al. Apr 2004 B2
6751560 Tingley et al. Jun 2004 B1
6754601 Eryurek et al. Jun 2004 B1
6758168 Koskinen et al. Jul 2004 B2
6859755 Eryurek et al. Feb 2005 B2
6904476 Hedtke Jun 2005 B2
6907383 Eryurek et al. Jun 2005 B2
6915364 Christensen et al. Jul 2005 B1
6970003 Rome et al. Nov 2005 B2
7018800 Huisenga et al. Mar 2006 B2
7040179 Drahm et al. May 2006 B2
7058542 Hauhia et al. Jun 2006 B2
7085610 Eryurek et al. Aug 2006 B2
7099852 Unsworth et al. Aug 2006 B2
7117122 Zielinski et al. Oct 2006 B2
7171281 Weber et al. Jan 2007 B2
7254518 Eryrurek et al. Aug 2007 B2
7421531 Rotvold et al. Sep 2008 B2
7480487 Smart et al. Jan 2009 B2
20020013629 Nixon et al. Jan 2002 A1
20020032544 Reid et al. Mar 2002 A1
20020077711 Nixon Jun 2002 A1
20020121910 Rome et al. Sep 2002 A1
20020145568 Winter Oct 2002 A1
20020148644 Schultz et al. Oct 2002 A1
20020167904 Borgeson et al. Nov 2002 A1
20020169582 Eryurek et al. Nov 2002 A1
20020194547 Christenson et al. Dec 2002 A1
20030033040 Billings Feb 2003 A1
20030045962 Eryurek et al. Mar 2003 A1
20030236937 Barros De Almeida et al. Dec 2003 A1
20040012264 Burger et al. Jan 2004 A1
20040111238 Kantzes et al. Jun 2004 A1
20040128034 Lenker et al. Jul 2004 A1
20040199361 Lu et al. Oct 2004 A1
20040203434 Karschnia et al. Oct 2004 A1
20040228184 Mathiowetz Nov 2004 A1
20040230327 Opheim et al. Nov 2004 A1
20040249583 Eryurek et al. Dec 2004 A1
20050072239 Longsdorf et al. Apr 2005 A1
20050225923 Howald Oct 2005 A1
20060075009 Lenz et al. Apr 2006 A1
20060080631 Koo Apr 2006 A1
20060161359 Lalla Jul 2006 A1
20060244424 Nelson Nov 2006 A1
20060277000 Wehrs Dec 2006 A1
20060291438 Karschnia et al. Dec 2006 A1
20070010968 Longsdorf et al. Jan 2007 A1
20080114911 Schumacher May 2008 A1
Foreign Referenced Citations (113)
Number Date Country
999950 Nov 1976 CA
1185841 Jun 1998 CN
32 13 866 Oct 1983 DE
35 40 204 Sep 1986 DE
40 08 560 Sep 1990 DE
43 43 747 Jun 1994 DE
44 33 593 Jun 1995 DE
195 02 499 Aug 1996 DE
296 00 609 Mar 1997 DE
197 04 694 Aug 1997 DE
19930660 Jul 1999 DE
199 05 071 Aug 2000 DE
19905071 Aug 2000 DE
299 17 651 Dec 2000 DE
199 47 129 Apr 2001 DE
100 36 971 Feb 2002 DE
102 23 725 Apr 2003 DE
0 807 804 EP
0 122 622 Oct 1984 EP
0 413 814 Feb 1991 EP
0 487 419 May 1992 EP
0 512 794 Nov 1992 EP
0 594 227 Apr 1994 EP
0 624 847 Nov 1994 EP
0 644 470 Mar 1995 EP
0 697 586 Feb 1996 EP
0 749 057 Dec 1996 EP
0 825 506 Jul 1997 EP
0 827 096 Sep 1997 EP
0 838 768 Sep 1997 EP
1 058 093 May 1999 EP
0 335 957 Nov 1999 EP
1 022 626 Jul 2000 EP
1 819 028 Aug 2007 EP
2 302 514 Sep 1976 FR
2 334 827 Jul 1977 FR
928704 Jun 1963 GB
1 534 280 Nov 1978 GB
1 534 288 Nov 1978 GB
2 310 346 Aug 1997 GB
2 317 969 Apr 1998 GB
2 342 453 Apr 2000 GB
2 347 232 Aug 2000 GB
56-031573 Mar 1981 JP
57196619 Feb 1982 JP
58-129316 Aug 1983 JP
59-116811 Jul 1984 JP
59-163520 Sep 1984 JP
59-176643 Oct 1984 JP
59-211196 Nov 1984 JP
59-211896 Nov 1984 JP
60-000507 Jan 1985 JP
60-76619 May 1985 JP
60-131495 Jul 1985 JP
60-174915 Sep 1985 JP
62-30915 Feb 1987 JP
62-080535 Apr 1987 JP
62-50901 Sep 1987 JP
63-169532 Jul 1988 JP
64-01914 Jan 1989 JP
64-72699 Mar 1989 JP
11-87430 Jul 1989 JP
2-05105 Jan 1990 JP
3-229124 Oct 1991 JP
4-70906 Mar 1992 JP
5-122768 May 1993 JP
6-95882 Apr 1994 JP
06242192 Sep 1994 JP
06-248224 Oct 1994 JP
7-063586 Mar 1995 JP
07234988 Sep 1995 JP
8-054923 Feb 1996 JP
8-102241 Apr 1996 JP
08-114638 May 1996 JP
8-136386 May 1996 JP
8-166309 Jun 1996 JP
8-247076 Sep 1996 JP
8-313466 Nov 1996 JP
2712625 Oct 1997 JP
2712701 Oct 1997 JP
2753592 Mar 1998 JP
07225530 May 1998 JP
10-232170 Sep 1998 JP
11-083575 Mar 1999 JP
11-112524 Apr 1999 JP
2190267 Sep 2002 RU
39728 Aug 2004 RU
2 394 124 Apr 2004 UK
WO 9425933 Nov 1994 WO
WO 9523361 Aug 1995 WO
WO 9611389 Apr 1996 WO
WO 9612993 May 1996 WO
WO 9639617 Dec 1996 WO
WO 9721157 Jun 1997 WO
WO 9725603 Jul 1997 WO
WO 9806024 Feb 1998 WO
WO 9813677 Apr 1998 WO
WO 9814855 Apr 1998 WO
WO 9820469 May 1998 WO
WO 9839718 Sep 1998 WO
WO 9919782 Apr 1999 WO
WO 0041050 Jul 2000 WO
WO 0050851 Aug 2000 WO
WO 0055700 Sep 2000 WO
WO 0070531 Nov 2000 WO
WO 0101213 Jan 2001 WO
WO 0119440 Mar 2001 WO
WO 0177766 Oct 2001 WO
WO 0190704 Nov 2001 WO
WO 0227418 Apr 2002 WO
WO 03081002 Oct 2003 WO
WO 2009003146 Dec 2008 WO
WO 2009003148 Dec 2008 WO
Related Publications (1)
Number Date Country
20060282580 A1 Dec 2006 US
Provisional Applications (1)
Number Date Country
60688657 Jun 2005 US