WO1995024003A1 - Interface apparatus for two-wire communication in process control loops - Google Patents
Interface apparatus for two-wire communication in process control loops Download PDFInfo
- Publication number
- WO1995024003A1 WO1995024003A1 PCT/US1995/001901 US9501901W WO9524003A1 WO 1995024003 A1 WO1995024003 A1 WO 1995024003A1 US 9501901 W US9501901 W US 9501901W WO 9524003 A1 WO9524003 A1 WO 9524003A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- interface apparatus
- communication signal
- component
- controller
- output signal
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B15/00—Systems controlled by a computer
- G05B15/02—Systems controlled by a computer electric
Definitions
- This invention relates generally to a process control system including a process controller and process instruments and more particularly to an interface apparatus for use in such a system.
- Process instruments such as current-to- pressure transducers and valve positioners are conventionally employed in industrial processes and are controlled by a process controller which is generally located remotely from and coupled to the transducer or positioner by a two-wire link.
- the process, controller provides a variable DC control current signal of between 4 and 20 mA over the two- wire link to the transducer or positioner or to any other controllable device or instrument.
- the control current level changes the state of the controllable device in proportion to the strength of the variable DC current signal.
- a valve positioner might fully open a valve in response to a 4 mA control current and fully close the valve in response to a 20 mA control current.
- variable parameters which may be adjusted to control the operating characteristics of such devices.
- these devices or process instruments were adjusted manually when it was necessary to change the instrument parameters such as the zero level, instrument range, output pressure, or valve travel.
- the presence of the modulated digital communication signals, i.e., the AC communication signals on the two-wire control loop can adversely affect the performance of the process control system, and undesirable characteristics of the process controller can adversely affect the AC communication signals.
- some process controllers have an output impedance that is low enough to attenuate the communication signal so that the communication signal cannot be reliably detected by the field instrument.
- some process controllers output a 4-20 mA DC analog control signal containing transients, noise, or other undesired AC components that can interfere with the modulated digital communication signals on the two-wire control loop.
- the modulation of voltage on the two-wire control loop can adversely affect the output current of the process controller or current readback circuits.
- Such an interface apparatus must be designed to regulate the analog control signal to remove unwanted noise therefrom and to effectively isolate the process controller from the digital communication signal by providing the interface apparatus with an output having a high impedance to frequencies present in the digital communication signal.
- a passive RC circuit for example, either has an output impedance that is too low to allow modulation of the voltage by the communication signal or has an input-to-output head voltage that is too high to maintain electrical compatibility between the process controller output signal and the device.
- an inductor could achieve some of the benefits of the present invention, but, the inductor would have to be prohibitively large and heavy in order to achieve those benefits.
- a process control system includes a process controller that develops a controller output signal having at least a desired DC component and an undesired AC component and a smart field device having a digitally adjustable parameter.
- An interface apparatus is coupled to the process controller and to the device via a two-wire loop, and means are provided for coupling a communication signal onto the two-wire loop between the interface apparatus and the device.
- the interface apparatus of the present invention includes means for substantially attenuating the undesired AC component from the process controller and means electrically coupled to the attenuating means for substantially preventing the communication signal from electrically affecting the process controller or from being so attenuated as to be undetectable.
- the device is responsive to the DC component of the controller output signal, and the adjustable parameter of the device is responsive to the communication signal.
- the interface apparatus includes means for substantially attenuating the undesired AC component of the controller output signal in the interface output signal and means electrically coupled to the attenuating means for substantially preventing the communication signal from electrically affecting the process controller.
- the interface apparatus is coupled between the first and second controller output terminals and the first and second device input terminals, and the communication signal is coupled to the two-wire loop between the interface apparatus and the device.
- the interface apparatus of the present invention enables reliable bidirectional transmission of a communication signal to be achieved between the field instrument and a communication site remote from the field instrument over the same two-wire loop on which the process controller transmits control signals to the field instrument. Accordingly, it is possible to provide such bidirectional communication without the need for costly and burdensome installation of additional wiring.
- the interface apparatus of the present invention prevents the communication signal from adversely affecting the performance of the process controller and from being so attenuated as to be undetectable and also attenuates noise introduced onto the two-wire loop by the process controller so that such noise cannot interfere appreciably with the communication signal.
- the interface apparatus is an active device powered, at least in part, by the controller output signal and includes a capacitor coupled to the process controller output.
- An adjustable voltage reference circuit and a high-impedance current source substantially prevent the communication signal from electrically affecting the process controller.
- Fig. 2 is a schematic diagram illustrating a preferred embodiment of the interface apparatus shown in Fig. 1.
- a process control system 20 includes a process controller 22 coupled to a two-wire control loop 24 including first and second wires 26, 28.
- a highway- addressable remote transducer (HART) field instrument or device 30 such as a current-to- pressure transducer or valve positioner is also coupled to the control wires 26, 28.
- An intrinsic safety barrier 32 may optionally be coupled to the control wires 26, 28 between the process controller 22 and the device 30.
- the intrinsic safety barrier 32 is an energy limiter that substantially prevents electrical signals on the control loop 24 between the barrier 32 and the field instrument 30 from igniting combustible or flammable materials present in the hazardous environments in which the field instrument 30 is commonly used.
- an interface apparatus 34 is coupled to the control loop 24 between the process controller 22 and the field instrument 30.
- the interface apparatus 34 has first and second interface input terminals 36, 38 which are coupled to first and second controller output terminals 40, 42 of the process controller 22.
- the interface apparatus 34 also includes first and second interface output terminals 44, 46 which are coupled to first and second barrier input terminals 48, 50 of the intrinsic safety barrier 32.
- the intrinsic safety barrier 32 includes first and second barrier output terminals 52, 54 which, in turn, are coupled to first and second device input terminals 56, 58 of the device 30.
- the first and second interface output terminals 44, 46 are respectively coupled directly to the first and second device input terminals 56, 58 of the device 30.
- the intrinsic safety barrier 32 is a conventional device which forms no part of the present invention
- the output produced by the interface apparatus 34 of the present invention enables the interface apparatus 34 to be used compatibly with an intrinsic safety barrier 32 in those applications where one is necessary.
- the intrinsic safety barrier 34 when present, is also electrically compatible with the communication signal (described below) which is coupled onto the first and second wires 26, 28 of the two-wire control loop 24.
- the device 30 is a so-called "smart" device capable of receiving a communication signal from an external source for setting parameters and making adjustments to components of the device 30.
- the device 30 is also capable of providing information to the communication site to facilitate diagnostic testing and interrogation of the device 30 by an operator of the process control system 20.
- a hand ⁇ held communicator 60 is coupled to the two-wire control loop 24.
- the communicator 60 is coupled to the two-wire control loop 24 near the output of the interface apparatus 34, but the communicator 60 can be coupled to the two-wire control loop 24 at any convenient location between the interface apparatus 34 and the field instrument or device 30 (on either side of the intrinsic safety barrier 32, if present).
- the hand-held communicator 60 is operable to provide communication signals to the device 30 via the two-wire control loop 24 in order to permit a system operator to adjust parameters of the device 30 and interrogate the device 30 to check the status thereof. While Fig. 1 depicts a hand-held communicator 60, such as the Fisher-Rosemount Model 268 hand-held communicator, any suitable equipment may be used to facilitate communication with the device 30.
- the communication signals conveyed to and from the device 30 on the first and second control loop wires 26, 28 are modulated digital communication signals, i.e., AC communication signals modulated onto the variable DC control signal provided by the interface apparatus 34 to the device 30.
- These AC communication signals could disrupt the operation of the process controller 22 in the absence of the interface apparatus 34.
- the process controller 22 could produce distortion in the variable DC component of the control signal, and this distortion could interfere with the communication signal when present on the control loop 24.
- the interface apparatus 34 is coupled between the process controller 22 and the device 30.
- the interface apparatus 34 is preferably an active device which is powered, at least in part, by the controller output signal.
- the interface apparatus 34 has a high-impedance output which prevents the communication signal from interfering with the process controller 22 and ensures that the communication signal is not so attenuated by the interface apparatus 34 as to be undetectable by the device 30.
- the interface apparatus 34 also filters the controller output signal to prevent noise, transients, or other undesired AC components produced by the process controller 22 from interfering with the communication signal when present on the control loop 24.
- the interface apparatus 34 includes a capacitor 66 connected across the control loop wires 26, 28 for filtering the controller output signal developed by the process controller 22 and for storing energy therein.
- the interface apparatus 34 also includes a current drive stage 68.
- the current drive stage 68 delivers a high-impedance output current to the interface output terminals 44, 46 as a function of the voltage across the capacitor 66.
- the high-impedance characteristic of the current output is provided by the open-drain configuration of the enhancement-mode p-channel field-effect transistor 70.
- the electrical network 72 includes a transistor 76 that provides a voltage offset to maintain the adjustable voltage reference 74 within its operating limits as the input voltage to the interface apparatus 34 is adjusted.
- the high-impedance output current may be.developed by any suitable means and that the enhancement-mode p-channel transistor is described herein simply as an example.
- the capacitor 66 In operation, upon the initial application of current from the controller 22, the capacitor 66 begins to charge. When the capacitor 66 is charged beyond the set voltage of the transistor 70, an output current appears at the high-impedance output terminals 44, 46 of the interface apparatus 34.
- the desired output current can only flow from the interface apparatus 34 when a first potential difference between the first and second interface output terminals 44, 46 is lower than a second potential difference between the first and second interface input terminals 36, 38.
- This required input-to-output voltage difference termed the "voltage drop” must be small enough to ensure that the DC component of the controller output signal, which is coupled by the interface apparatus 34 to the device 30, is electrically compatible with the device 30.
- the voltage drop produced by the interface apparatus 34 is too high, the device 30 will not be controlled properly by the process controller 22.
- the interface apparatus 34 as shown in Fig. 2 generally will require a voltage drop of at least two volts for proper operation, but the voltage drop must nonetheless be small enough to ensure compatibility between the controller 22 and the device 30.
- the actual output voltage of the interface will be determined by the output current and the load impedance. Also, in this embodiment, wherein the interface apparatus 34 is powered solely by the control signal, the interface apparatus 34 draws an operating current of approximately forty to sixty microamps from the loop.
- a diode 78 is connected between the first and second interface input terminals 36, 38 of the interface apparatus 34 to protect the interface apparatus 34 from damage that may result if the interface apparatus 34 is coupled to the process controller 22 with the incorrect polarity.
- a diode 80 is connected between the first and second interface output terminals 44, 46 of the interface apparatus 34 to prevent damage that may result from static discharge or from the interface apparatus 34 being improperly installed in the loop.
- the connector 64 for example, a 2-conductor AMP "Mini Universal Mate-N- Lock" connector, is coupled to the first and second interface output terminals 44, 46.
- the connector 64 is intended for use with a hand-held communicator, such as the Fisher-Rosemount Model 268, or with a HART-compatible multiplexing device, either of which must be provided with a mating connector 62 as described above.
- the communicator 60 may be coupled directly to the two- wire control loop 24 at any desired location between the interface apparatus 34 and the device 30; the connector 64 is provided simply for convenience.
- Figs. 1 and 2 represent only one embodiment of the present invention.
- One alternative could be a circuit employing an operational amplifier suitably configured to serve as a high-impedance current source along with means for regulating the output current from the process controller 22.
- an operational amplifier suitably configured to serve as a high-impedance current source along with means for regulating the output current from the process controller 22.
- many other network designs will be apparent to those of ordinary skill in the art following the principle of the invention and the teachings herein.
Abstract
Description
Claims
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP52291595A JP3641711B2 (en) | 1994-03-02 | 1995-02-10 | Interface device for two-wire communication in a process control loop |
DE69517680T DE69517680T2 (en) | 1994-03-02 | 1995-02-10 | INTERFACE FOR TWO-WIRE COMMUNICATION IN PROCESS CONTROL LOOPES |
EP95909557A EP0748468B1 (en) | 1994-03-02 | 1995-02-10 | Interface apparatus for two-wire communication in process control loops |
CA002184618A CA2184618C (en) | 1994-03-02 | 1995-02-10 | Interface apparatus for two-wire communication in process control loops |
MX9603604A MX9603604A (en) | 1994-03-02 | 1995-02-10 | Interface apparatus for two-wire communication in process control loops. |
AT95909557T ATE194231T1 (en) | 1994-03-02 | 1995-02-10 | INTERFACE FOR TWO-WIRE COMMUNICATION IN PROCESS CONTROL LOOP |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/204,636 | 1994-03-02 | ||
US08/204,636 US5434774A (en) | 1994-03-02 | 1994-03-02 | Interface apparatus for two-wire communication in process control loops |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1995024003A1 true WO1995024003A1 (en) | 1995-09-08 |
Family
ID=22758772
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1995/001901 WO1995024003A1 (en) | 1994-03-02 | 1995-02-10 | Interface apparatus for two-wire communication in process control loops |
Country Status (8)
Country | Link |
---|---|
US (1) | US5434774A (en) |
EP (1) | EP0748468B1 (en) |
JP (1) | JP3641711B2 (en) |
AT (1) | ATE194231T1 (en) |
CA (1) | CA2184618C (en) |
DE (1) | DE69517680T2 (en) |
MX (1) | MX9603604A (en) |
WO (1) | WO1995024003A1 (en) |
Families Citing this family (98)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6654697B1 (en) | 1996-03-28 | 2003-11-25 | Rosemount Inc. | Flow measurement with diagnostics |
US6539267B1 (en) | 1996-03-28 | 2003-03-25 | Rosemount Inc. | Device in a process system for determining statistical parameter |
US6017143A (en) | 1996-03-28 | 2000-01-25 | Rosemount Inc. | Device in a process system for detecting events |
US8290721B2 (en) | 1996-03-28 | 2012-10-16 | Rosemount Inc. | Flow measurement diagnostics |
US7949495B2 (en) | 1996-03-28 | 2011-05-24 | Rosemount, Inc. | Process variable transmitter with diagnostics |
US6424872B1 (en) | 1996-08-23 | 2002-07-23 | Fieldbus Foundation | Block oriented control system |
US20040194101A1 (en) * | 1997-08-21 | 2004-09-30 | Glanzer David A. | Flexible function blocks |
US7146230B2 (en) * | 1996-08-23 | 2006-12-05 | Fieldbus Foundation | Integrated fieldbus data server architecture |
US5936514A (en) * | 1996-09-27 | 1999-08-10 | Rosemount Inc. | Power supply input circuit for field instrument |
US6044305A (en) * | 1996-10-04 | 2000-03-28 | Fisher Controls International, Inc. | Method and apparatus for debugging and tuning a process control network having distributed control functions |
US6047222A (en) * | 1996-10-04 | 2000-04-04 | Fisher Controls International, Inc. | Process control network with redundant field devices and buses |
BR9712194A (en) | 1996-10-04 | 1999-08-31 | Fisher Controls Int | Interface between a communications network and a process control system, software program that implements an interface between a communications network and a process control system to run on a processor, manufacturing article implementing a software program interface between a communications network and a process control system to run on a processor; and, an interface adapted to be coupled between a remote communications network and a process control system. |
US5970430A (en) * | 1996-10-04 | 1999-10-19 | Fisher Controls International, Inc. | Local device and process diagnostics in a process control network having distributed control functions |
CA2267528C (en) * | 1996-10-04 | 2006-04-04 | Fisher Controls International, Inc. | Maintenance interface device for use in a process control network |
US6754601B1 (en) | 1996-11-07 | 2004-06-22 | Rosemount Inc. | Diagnostics for resistive elements of process devices |
US6601005B1 (en) | 1996-11-07 | 2003-07-29 | Rosemount Inc. | Process device diagnostics using process variable sensor signal |
US6519546B1 (en) | 1996-11-07 | 2003-02-11 | Rosemount Inc. | Auto correcting temperature transmitter with resistance based sensor |
US6999824B2 (en) * | 1997-08-21 | 2006-02-14 | Fieldbus Foundation | System and method for implementing safety instrumented systems in a fieldbus architecture |
US6035878A (en) * | 1997-09-22 | 2000-03-14 | Fisher Controls International, Inc. | Diagnostic device and method for pressure regulator |
US6056008A (en) * | 1997-09-22 | 2000-05-02 | Fisher Controls International, Inc. | Intelligent pressure regulator |
US6014612A (en) * | 1997-10-02 | 2000-01-11 | Fisher Controls International, Inc. | Remote diagnostics in a process control network having distributed control functions |
US6088665A (en) * | 1997-11-03 | 2000-07-11 | Fisher Controls International, Inc. | Schematic generator for use in a process control network having distributed control functions |
US6233285B1 (en) | 1997-12-23 | 2001-05-15 | Honeywell International Inc. | Intrinsically safe cable drive circuit |
DE19813700C2 (en) * | 1998-03-27 | 2003-03-27 | Samson Ag | Input circuit for a field device |
IT1302218B1 (en) * | 1998-09-16 | 2000-09-05 | Abb Kent Taylor Spa | READING AND PROGRAMMING DEVICE FOR DIPRESSION, TEMPERATURE AND SIMILAR TRANSMITTERS. |
US8172546B2 (en) * | 1998-11-23 | 2012-05-08 | Entegris, Inc. | System and method for correcting for pressure variations using a motor |
US7029238B1 (en) * | 1998-11-23 | 2006-04-18 | Mykrolis Corporation | Pump controller for precision pumping apparatus |
FI111106B (en) * | 1999-02-19 | 2003-05-30 | Neles Controls Oy | Procedure for setting a process control loop in an industrial process |
US6186167B1 (en) * | 1999-03-04 | 2001-02-13 | Fisher Controls International Inc. | Emergency shutdown test system |
US6510351B1 (en) | 1999-03-15 | 2003-01-21 | Fisher-Rosemount Systems, Inc. | Modifier function blocks in a process control system |
US6701274B1 (en) | 1999-08-27 | 2004-03-02 | Rosemount Inc. | Prediction of error magnitude in a pressure transmitter |
US6618745B2 (en) | 1999-09-10 | 2003-09-09 | Fisher Rosemount Systems, Inc. | Linking device in a process control system that allows the formation of a control loop having function blocks in a controller and in field devices |
ATE385114T1 (en) * | 1999-11-25 | 2008-02-15 | S Rain Control As | TWO-WIRE CONTROL AND MONITORING SYSTEM, ESPECIALLY FOR IRRIGATION OF LIMITED AREAS |
US7421317B2 (en) * | 1999-11-25 | 2008-09-02 | S-Rain Control A/S | Two-wire controlling and monitoring system for the irrigation of localized areas of soil |
US6325932B1 (en) * | 1999-11-30 | 2001-12-04 | Mykrolis Corporation | Apparatus and method for pumping high viscosity fluid |
US6357335B1 (en) | 1999-12-23 | 2002-03-19 | Sox Corporation | Pneumatic volume booster for valve positioner |
US20050240286A1 (en) * | 2000-06-21 | 2005-10-27 | Glanzer David A | Block-oriented control system on high speed ethernet |
DE10054288A1 (en) * | 2000-11-02 | 2002-05-16 | Festo Ag & Co | Sensor arrangement for recording at least one measured value |
JPWO2002041917A1 (en) * | 2000-11-22 | 2004-03-25 | 三菱ウェルファーマ株式会社 | Ophthalmic agent |
CN1288520C (en) * | 2001-04-05 | 2006-12-06 | 费希尔控制国际公司 | System to manually initiate an emergency shutdown test and collect diagnostic data in process control environment |
US7621293B2 (en) * | 2001-04-05 | 2009-11-24 | Fisher Controls International Llc | Versatile emergency shutdown device controller implementing a pneumatic test for a system instrument device |
US6859755B2 (en) | 2001-05-14 | 2005-02-22 | Rosemount Inc. | Diagnostics for industrial process control and measurement systems |
US6629059B2 (en) | 2001-05-14 | 2003-09-30 | Fisher-Rosemount Systems, Inc. | Hand held diagnostic and communication device with automatic bus detection |
US6772036B2 (en) | 2001-08-30 | 2004-08-03 | Fisher-Rosemount Systems, Inc. | Control system using process model |
US20030229472A1 (en) * | 2001-12-06 | 2003-12-11 | Kantzes Christopher P. | Field maintenance tool with improved device description communication and storage |
US20030204373A1 (en) * | 2001-12-06 | 2003-10-30 | Fisher-Rosemount Systems, Inc. | Wireless communication method between handheld field maintenance tools |
US7426452B2 (en) * | 2001-12-06 | 2008-09-16 | Fisher-Rosemount Systems. Inc. | Dual protocol handheld field maintenance tool with radio-frequency communication |
US6889166B2 (en) * | 2001-12-06 | 2005-05-03 | Fisher-Rosemount Systems, Inc. | Intrinsically safe field maintenance tool |
US7039744B2 (en) * | 2002-03-12 | 2006-05-02 | Fisher-Rosemount Systems, Inc. | Movable lead access member for handheld field maintenance tool |
US7027952B2 (en) * | 2002-03-12 | 2006-04-11 | Fisher-Rosemount Systems, Inc. | Data transmission method for a multi-protocol handheld field maintenance tool |
US7054337B2 (en) * | 2002-03-15 | 2006-05-30 | Fisher Controls International Llc. | Method and apparatus for optimizing communications in a multiplexer network |
US10261506B2 (en) * | 2002-12-05 | 2019-04-16 | Fisher-Rosemount Systems, Inc. | Method of adding software to a field maintenance tool |
CN100388529C (en) * | 2003-03-06 | 2008-05-14 | 费希尔-罗斯蒙德系统公司 | Heat flow regulating cover for an electrical storage cell |
EP1619994A4 (en) * | 2003-04-16 | 2009-03-11 | Univ Drexel | Acoustic blood analyzer for assessing blood properties |
US7512521B2 (en) * | 2003-04-30 | 2009-03-31 | Fisher-Rosemount Systems, Inc. | Intrinsically safe field maintenance tool with power islands |
US7054695B2 (en) | 2003-05-15 | 2006-05-30 | Fisher-Rosemount Systems, Inc. | Field maintenance tool with enhanced scripts |
US7036386B2 (en) * | 2003-05-16 | 2006-05-02 | Fisher-Rosemount Systems, Inc. | Multipurpose utility mounting assembly for handheld field maintenance tool |
US7526802B2 (en) * | 2003-05-16 | 2009-04-28 | Fisher-Rosemount Systems, Inc. | Memory authentication for intrinsically safe field maintenance tools |
US7199784B2 (en) * | 2003-05-16 | 2007-04-03 | Fisher Rosemount Systems, Inc. | One-handed operation of a handheld field maintenance tool |
US8874402B2 (en) * | 2003-05-16 | 2014-10-28 | Fisher-Rosemount Systems, Inc. | Physical memory handling for handheld field maintenance tools |
US6925419B2 (en) * | 2003-05-16 | 2005-08-02 | Fisher-Rosemount Systems, Inc. | Intrinsically safe field maintenance tool with removable battery pack |
DE10344575A1 (en) * | 2003-09-25 | 2005-04-28 | Siemens Ag | Device for transmitting data and portable electronic device and field device for such a device |
JP5079516B2 (en) | 2004-11-23 | 2012-11-21 | インテグリス・インコーポレーテッド | System and method for a variable home position dispensing system |
US8112565B2 (en) | 2005-06-08 | 2012-02-07 | Fisher-Rosemount Systems, Inc. | Multi-protocol field device interface with automatic bus detection |
US7556238B2 (en) * | 2005-07-20 | 2009-07-07 | Fisher Controls International Llc | Emergency shutdown system |
US20070060044A1 (en) * | 2005-09-14 | 2007-03-15 | Michael Lamb | Portable music system |
US20070068225A1 (en) | 2005-09-29 | 2007-03-29 | Brown Gregory C | Leak detector for process valve |
US8753097B2 (en) | 2005-11-21 | 2014-06-17 | Entegris, Inc. | Method and system for high viscosity pump |
WO2007061956A2 (en) | 2005-11-21 | 2007-05-31 | Entegris, Inc. | System and method for a pump with reduced form factor |
US8025486B2 (en) * | 2005-12-02 | 2011-09-27 | Entegris, Inc. | System and method for valve sequencing in a pump |
WO2007067354A2 (en) * | 2005-12-02 | 2007-06-14 | Entegris, Inc. | I/o systems, methods and devices for interfacing a pump controller |
CN102705209B (en) | 2005-12-02 | 2015-09-30 | 恩特格里公司 | For system and method pressure compensated in pump |
US7878765B2 (en) * | 2005-12-02 | 2011-02-01 | Entegris, Inc. | System and method for monitoring operation of a pump |
US7850431B2 (en) * | 2005-12-02 | 2010-12-14 | Entegris, Inc. | System and method for control of fluid pressure |
WO2007067343A2 (en) * | 2005-12-02 | 2007-06-14 | Entegris, Inc. | O-ring-less low profile fittings and fitting assemblies |
US8083498B2 (en) | 2005-12-02 | 2011-12-27 | Entegris, Inc. | System and method for position control of a mechanical piston in a pump |
US20070128061A1 (en) * | 2005-12-02 | 2007-06-07 | Iraj Gashgaee | Fixed volume valve system |
JP5345853B2 (en) * | 2005-12-05 | 2013-11-20 | インテグリス・インコーポレーテッド | Error volume system and method for pumps |
US7489977B2 (en) * | 2005-12-20 | 2009-02-10 | Fieldbus Foundation | System and method for implementing time synchronization monitoring and detection in a safety instrumented system |
US8676357B2 (en) * | 2005-12-20 | 2014-03-18 | Fieldbus Foundation | System and method for implementing an extended safety instrumented system |
TWI402423B (en) | 2006-02-28 | 2013-07-21 | Entegris Inc | System and method for operation of a pump |
US7684446B2 (en) | 2006-03-01 | 2010-03-23 | Entegris, Inc. | System and method for multiplexing setpoints |
US7494265B2 (en) * | 2006-03-01 | 2009-02-24 | Entegris, Inc. | System and method for controlled mixing of fluids via temperature |
US7953501B2 (en) | 2006-09-25 | 2011-05-31 | Fisher-Rosemount Systems, Inc. | Industrial process control loop monitor |
US8788070B2 (en) | 2006-09-26 | 2014-07-22 | Rosemount Inc. | Automatic field device service adviser |
CN101517377B (en) | 2006-09-29 | 2012-05-09 | 罗斯蒙德公司 | Magnetic flowmeter with verification |
JP5097820B2 (en) * | 2007-06-13 | 2012-12-12 | フィッシャー−ローズマウント システムズ,インコーポレイテッド | Function improvement method of portable field maintenance equipment |
US8898036B2 (en) | 2007-08-06 | 2014-11-25 | Rosemount Inc. | Process variable transmitter with acceleration sensor |
US20090302588A1 (en) * | 2008-06-05 | 2009-12-10 | Autoliv Asp, Inc. | Systems and methods for airbag tether release |
CN102959363B (en) * | 2009-07-09 | 2015-11-25 | 罗斯蒙特公司 | There is the process variable transmitter of two-wire process control loop diagnostics |
US9207670B2 (en) | 2011-03-21 | 2015-12-08 | Rosemount Inc. | Degrading sensor detection implemented within a transmitter |
EP2668845A1 (en) | 2012-05-31 | 2013-12-04 | S-Rain Control A/S | A two-wire controlling and monitoring system for in particular irrigation of localized areas of soil |
US9052240B2 (en) | 2012-06-29 | 2015-06-09 | Rosemount Inc. | Industrial process temperature transmitter with sensor stress diagnostics |
US9602122B2 (en) | 2012-09-28 | 2017-03-21 | Rosemount Inc. | Process variable measurement noise diagnostic |
US9439369B2 (en) | 2013-08-27 | 2016-09-13 | S-Rain Control A/S | Wired controlling and monitoring system for irrigation of localized areas of soil |
US10367612B2 (en) | 2015-09-30 | 2019-07-30 | Rosemount Inc. | Process variable transmitter with self-learning loop diagnostics |
US10724878B2 (en) | 2015-10-30 | 2020-07-28 | Fisher Controls International Llc | Methods and apparatus to correct remote sensor signals |
DE102016119548A1 (en) * | 2016-10-13 | 2018-04-19 | Endress+Hauser SE+Co. KG | Method for data transmission between a field device of automation technology and a communication box |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1991005293A1 (en) * | 1989-10-02 | 1991-04-18 | Rosemount Inc. | Field-mounted control unit |
Family Cites Families (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3905355A (en) * | 1973-12-06 | 1975-09-16 | Joseph Brudny | System for the measurement, display and instrumental conditioning of electromyographic signals |
US4007458A (en) * | 1975-12-29 | 1977-02-08 | Clemar Manufacturing Corporation | Digital two-wire irrigation control system |
US4131882A (en) * | 1975-12-29 | 1978-12-26 | Clemar Manufacturing Corporation | Digital two-wire irrigation control system with feedback |
FR2403695A1 (en) * | 1977-09-16 | 1979-04-13 | Cii Honeywell Bull | DEVICE FOR ENSURING THE POWER SUPPLY AND THE TRANSMISSION OF ELECTRIC SIGNALS BETWEEN TWO DEVICES THROUGH LOW NUMBER CONTACTS |
US4176395A (en) * | 1977-11-16 | 1979-11-27 | Clemar Manufacturing Corporation | Interactive irrigation control system |
US4190822A (en) * | 1978-04-05 | 1980-02-26 | Honeywell Inc. | Current telemetering interface apparatus |
US4481967A (en) * | 1979-11-15 | 1984-11-13 | Rosemount Inc. | Control circuit for current to pressure converter |
DE3127637C2 (en) * | 1980-08-01 | 1988-08-18 | Endress U. Hauser Gmbh U. Co, 7867 Maulburg | Arrangement for determining the level in a container |
US4387434A (en) * | 1980-10-24 | 1983-06-07 | Process Technologies, Inc. | Intelligent field interface device for fluid storage facility |
US4520488A (en) * | 1981-03-02 | 1985-05-28 | Honeywell, Inc. | Communication system and method |
JPS58120326A (en) * | 1982-01-11 | 1983-07-18 | Sharp Corp | Automatic receiving gain controlling system for centralized monitoring system |
US4556866A (en) * | 1983-03-16 | 1985-12-03 | Honeywell Inc. | Power line carrier FSK data system |
US4633217A (en) * | 1984-06-04 | 1986-12-30 | Yamatake Honeywell | Communication apparatus |
US4691328A (en) * | 1985-08-12 | 1987-09-01 | The Babcock & Wilcox Company | On-line serial communication interface from a computer to a current loop |
EP0239655A1 (en) * | 1986-04-01 | 1987-10-07 | Océ-Nederland B.V. | Electronic proportional-integral-controller in digital execution |
US4697166A (en) * | 1986-08-11 | 1987-09-29 | Nippon Colin Co., Ltd. | Method and apparatus for coupling transceiver to power line carrier system |
US4933668A (en) * | 1986-09-29 | 1990-06-12 | Shepherd Intelligence Systems, Inc. | Aircraft security system |
US5063371A (en) * | 1986-09-29 | 1991-11-05 | Oyer Michael W | Aircraft security system |
JPS63232694A (en) * | 1987-03-20 | 1988-09-28 | Yamatake Honeywell Co Ltd | Communication equipment |
US5099504A (en) * | 1987-03-31 | 1992-03-24 | Adaptive Technologies, Inc. | Thickness/density mesuring apparatus |
JPH0633723Y2 (en) * | 1987-09-03 | 1994-08-31 | 山武ハネウエル株式会社 | Communication device |
US4855714A (en) * | 1987-11-05 | 1989-08-08 | Emhart Industries, Inc. | Fluid status detector |
US4916628A (en) * | 1988-07-08 | 1990-04-10 | Commonwealth Edison Company | Microprocessor-based control/status monitoring arrangement |
US4940056A (en) * | 1988-11-15 | 1990-07-10 | Center For Innovative Technology | Electrogustograph |
ATE111273T1 (en) * | 1989-01-27 | 1994-09-15 | Siemens Ag | MESSAGE PROCESSING DEVICE TO BE INDUCTIVELY COUPLED. |
US4953986A (en) * | 1989-04-27 | 1990-09-04 | The United States Of America As Represented By The Secretary Of The Navy | Air/sea temperature probe |
US5151017A (en) * | 1991-05-15 | 1992-09-29 | Itt Corporation | Variable speed hydromassage pump control |
US5200930A (en) * | 1992-01-24 | 1993-04-06 | The Laitram Corporation | Two-wire multi-channel streamer communication system |
-
1994
- 1994-03-02 US US08/204,636 patent/US5434774A/en not_active Expired - Lifetime
-
1995
- 1995-02-10 JP JP52291595A patent/JP3641711B2/en not_active Expired - Lifetime
- 1995-02-10 DE DE69517680T patent/DE69517680T2/en not_active Expired - Lifetime
- 1995-02-10 WO PCT/US1995/001901 patent/WO1995024003A1/en active IP Right Grant
- 1995-02-10 MX MX9603604A patent/MX9603604A/en unknown
- 1995-02-10 AT AT95909557T patent/ATE194231T1/en not_active IP Right Cessation
- 1995-02-10 CA CA002184618A patent/CA2184618C/en not_active Expired - Lifetime
- 1995-02-10 EP EP95909557A patent/EP0748468B1/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1991005293A1 (en) * | 1989-10-02 | 1991-04-18 | Rosemount Inc. | Field-mounted control unit |
Non-Patent Citations (4)
Title |
---|
A. BRADSHAW: "Pressions, débits, niveaux... une régulation numérique directe", ELECTRONIQUE INDUSTRIELLE, no. 72, PARIS FR, pages 61 - 64 * |
G. PINKOWSKI: "Instrumentierungstechik im Wandel", AUTOMATISIERUNGSTECHNISCHE PRAXIS - ATP, vol. 34, no. 5, MUNCHEN DE, pages 247 - 254 * |
M. PANDIT ET AL: "Ein kommunikationsfähiger elektropneumatischer Stellungsregler", AUTOMATISIERUNGSTECHNISCHE PRAXIS - ATP, vol. 35, no. 7, pages 408 - 413, XP000382754 * |
P. GARRONE: "Smart transmitters get smarter", INSTRUMENTS AND CONTROL SYSTEMS, vol. 65, no. 9, RADNOR US, pages 77 - 81 * |
Also Published As
Publication number | Publication date |
---|---|
CA2184618A1 (en) | 1995-09-08 |
DE69517680D1 (en) | 2000-08-03 |
EP0748468B1 (en) | 2000-06-28 |
MX9603604A (en) | 1997-05-31 |
DE69517680T2 (en) | 2001-02-22 |
US5434774A (en) | 1995-07-18 |
JP3641711B2 (en) | 2005-04-27 |
CA2184618C (en) | 2004-11-09 |
EP0748468A1 (en) | 1996-12-18 |
JPH09510033A (en) | 1997-10-07 |
ATE194231T1 (en) | 2000-07-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5434774A (en) | Interface apparatus for two-wire communication in process control loops | |
EP1415451B1 (en) | Multi-protocol field device and communication method | |
EP0591926B1 (en) | Communication system and method | |
US6236334B1 (en) | Distributed control system for controlling material flow having wireless transceiver connected to industrial process control field device to provide redundant wireless access | |
US8049361B2 (en) | RF adapter for field device with loop current bypass | |
WO1988002509A1 (en) | Frequency feedback on a current loop of a current-to-pressure converter | |
US7211990B2 (en) | 4-20 mA interface circuit | |
EP3070555B1 (en) | Common-mode noise reduction circuit in a field device | |
EP2858257A1 (en) | Isolated signal transmission apparatus | |
JP3111529B2 (en) | Fieldbus systems, field devices and higher-level devices used in fieldbus systems | |
Cobb | Control in the field with HART® communications | |
CN111200570A (en) | Communication receiving interface of current loop | |
JPH07123031A (en) | Communications system for field equipment and its device | |
AU2815999A (en) | Apparatus for providing access to field devices in a distributed control system |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): CA JP MX |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: PA/a/1996/003604 Country of ref document: MX |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2184618 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1995909557 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1995909557 Country of ref document: EP |
|
WWG | Wipo information: grant in national office |
Ref document number: 1995909557 Country of ref document: EP |