Networked series of sensors having distributed measurement and control for use in a hazardous environment

• US 7,486,495 B1
• Filed: 05/16/2006
• Issued: 02/03/2009
• Est. Priority Date: 05/25/2005
• Status: Active Grant

• Current Assignee: Sensia, LLC (Rockwell Automation, Inc.)
• Original Assignee: Cameron International Corporation (SLB)
• Inventors: Madden, Thomas Michael, Yee, Jerry, Diederichs, Robert
• Primary Examiner(s): Edwards, Jr.; Timothy
• Application Number:
  US11/435,346
• Time in Patent Office: 994 Days
• Field of Search: 361/119, 340/870.07, 700/150, 700/266
• US Class Current: 361/119
• CPC Class Codes: G05B 19/4185 characterised by the network communication
• CPC Class Codes: G05B 2219/33343 Each slave stores communication program to be used by master, exchangeability
• CPC Class Codes: G05B 2219/34481 EFC explosion free control, intrinsically safe
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

The invention is a networked system of devices positioned in a hazardous environment to monitor or control process conditions. The devices include sensors such as pressure measurement elements and controls such as variable voltage outputs. The sensors detect process conditions and the controls manipulate process conditions, and they are monitored and controlled by slave devices having, generally a microprocessor and having associated memory to receive and record the sensor/control data. The network includes master devices; each master device may be associated with one or more slaved devices and associated sensors, where the master device communicates to its associated slave devices through a digital communication bus. The master device can automatically detect its associated slave devices and detect the communication and data characteristics of the slave devices. The master may also set parameters for detected slave devices, such as needed for computations performed by the master (using its own microprocessor) using data received from the slave device(s). The master device receives slave device data by requesting or polling the data from the slave device over the digital communication bus.

Claims

1. A networked system of devices positioned in a hazardous environment to monitor process conditions, comprising:

an intrinsically safe barrier (“

ISB”

) having a safe side and a hazardous side,

a network connected to said hazardous side of said ISB,

at least one sensor located on the hazardous side of said ISB, said sensor detecting process or ambient conditions,

at least one slave device of a plurality of slave devices connected to said network, said slave device including a microprocessor and memory to receive and record said sensor data,

at least one master device connected to said network, said master device and said slave device communicating to one another through a digital communications sub network of said network, wherein said sub network is a tier of said network such that said master device acts as a master only to those devices of the plurality of slave devices connected to the sub network;

said master device adapted to request portions of said recorded data from said slave device through said communications sub network and said slave device adapted to transmit said requested data to said master device through said communications sub network in response to said request;

said master device further adapted to manipulate said received slave data, said master device further being adapted to transmit said manipulated data on said communications sub network.

2. The networked system of claim 1 having a series of slave devices and a series of master devices, a subset of said series of slave devices in communication with a subset of said series of master devices through said communications sub network and forming a hierarchical network of devices in a master/slave tiered relationship.

3. The networked system of claim 2 wherein said communications sub-network includes a separate communications bus for each tier of said hierarchical network.

4. The networked system of claim 1 wherein said master device includes a memory to store said manipulated data.

5. The combination of the networked system of claim 2 and an external master device located on said safe side of said ISB, and wherein said master device located on said hazardous side of said ISB transmits said manipulated data to said external master device in response to a request for data from said external master device.

6. The networked system of claim 3 wherein said network further includes a power distribution sub network, said power distribution sub network receiving power external to said network and distributing power to said series of master devices and said series of slave devices positioned on said network along a common power bus.

7. The networked system of claim 6 wherein a subset of said slave devices or said master devices each are equipped with a replaceable battery, said battery quipped slave devices are adapted to distribute power through said power distribution sub-network when said external power is insufficient or lacking.

10. The networked system of claim 6 wherein said power distribution sub network is configured for delivering power at a voltage below approximately 6 volts DC, at a maximum amperage of about 3000 milliamps, having a maximum capacitance of approximately 450 uF of capacitance.

11. The networked system of claim 7 wherein said battery backup is sufficient to operate for a period of more than 1 year at the power distribution configuration of claim 10.

12. The networked system of claim 1 further having a series of sensors and slave devices located on said hazardous side of said ISB, each slave device associated with one of said sensors, each slave device adapted to receive and record data from said associated sensor, each of said slave devices in communication with said master device through said communications sub network, and each slave device communicating said recorded data to said master device upon request for data from said master device.

8. A networked system of devices positioned in a hazardous environment to monitor process conditions, comprising:

an intrinsically safe barrier (“

ISB”

) having a safe side and a hazardous side, a network connected to said hazardous side of said ISB,

at least one sensor located on the hazardous side of said ISB, said sensor detecting process conditions,

at least one slave device of a plurality of slave devices connected to said network, said slave device including a microprocessor and memory to receive and record said sensor data,

at least one master device connected to said network, said master device and said slave device communicating to one another through a digital communications sub network of said network, wherein said sub network is a tier of said network such that said master device acts as a master only to those devices of the plurality of slave devices connected to the sub network;

said master device adapted to request portions of said recorded data from said slave device through said communications sub network and said slave device adapted to transmit said requested data to said master device through said communications sub network in response to said request;

said master device further adapted to manipulate said received slave data, said master device further being adapted to transmit said manipulated data on said communications sub network, wherein said system further includes a means to automatically detect the communication parameters of said slave devices.

9. A networked system of devices positioned in a hazardous environment to monitor process conditions, comprising:

an intrinsically safe barrier (ISB”

) having a safe side and a hazardous side, a network connected to said hazardous side of said ISB,

at least one sensor located on the hazardous side of said ISR, said sensor detecting process conditions,

at least one slave device of a plurality of slave devices connected to said network, said slave device including a microprocessor and memory to receive and record said sensor data,

at least one master device connected to said network, said master device and said slave device communicating to one another through a digital communications sub network of said network, wherein said sub network is a tier of said network such that said master device acts as a master only to those devices of the plurality of slave devices connected to the sub network;

said master device adapted to request portions of said recorded data from said slave device through said communications sub network and said slave device adapted to transmit said requested data to said master device through said communications sub network in response to said request;

said master device further adapted to manipulate said received slave data, said master device further being adapted to transmit said manipulated data on said communications sub network wherein said system further includes a means to automatically configure the data transmissions between said master device and said slave device.

13. A networked system of devices positioned in a hazardous environment to monitor process conditions, comprising:

an intrinsically safe barrier (“

ISB”

) having a safe side and a hazardous side, a network connected to said hazardous side of said ISB,

a plurality of sensors located on the hazardous side of said ISB, each of said sensors detecting process or ambient conditions,

a plurality of slave devices connected to said network, each of said slave devices including a microprocessor and memory to receive and record an associated sensor'"'"'s data,

a plurality of master devices connected to said network, each of said master devices receiving data (a “

receiving master device”

) from zero or more of said plurality of slave devices through a digital communications sub network of said network in response to a request for data sent from said receiving master device addressed to a particular one of said stave devices, wherein said sub network is a tier of said network such that said master device acts as a master only to those devices of the plurality of slave devices connected to the sub network;

said receiving master devices adapted to manipulate said received data and store manipulated data or said received data and transmit said stored received or manipulated data to another of said plurality of master devices upon a request for transmission from said another of said master devices.

14. A low powered configured inherently safe network of devices positioned in a hazardous environment to monitor process conditions, comprising:

an intrinsically safe barrier (“

ISB”

) having a safe side and a hazardous side, a network connected to said hazardous side of said ISB,

a plurality of sensors located on the hazardous side of said ISB, each of said sensors detecting process or ambient conditions,

a plurality of slave devices connected to said network, each of said slave devices including a microprocessor and memory to receive and record an associated sensor'"'"'s data, where each slave device has capacitance of about less than 30 uF, and said slave device adapted to transmit said recorded data onto the network substantially only in response to a request for data by a master device received by said slave device transmitting the requested data,

wherein one or more of said slave devices communicates with a master device over a sub network of said network,

wherein said sub network is a tier of said network such that said master device acts as a master only to those devices of the plurality of slave devices connected to the sub network.

15. The low powered intrinsically safe network of claim 14 wherein said slave devices are powered through a single shared power bus.

16. A networked system of devices positioned in a hazardous environment to monitor process conditions, comprising:

an intrinsically safe barrier (“

ISB”

) having a safe side and a hazardous side,

a series of sensors and a series of slave devices on said hazardous side of said ISB, each slave device associated with at least one sensor and adapted to receive and record said associated sensor'"'"'s data,

a series of master devices, each master device communicating with a sub-set of said series of slave devices through a sub-branch communications bus, wherein said sub-set is a tier of said network such that each master device acts as a master only to those devices of the series of slave devices in the sub-set, each of said master devices adapted to request portions of said recorded data from each of said associated slave devices through said communications bus and said associated sub-set of said slave devices adapted to transmit said requested data to said requesting master device through said communications bus in response to said request;

each of said master devices further having a processor adapted to manipulate said associated slave data, said master device further being adapted to transmit said manipulated data on said communications bus to another of said master or slave devices.

17. The networked system of devices according to claim 16 wherein each of said master devices and subset of associated slave devices communicates over a separate dedicated sub-branch communications bus.

18. The networked system of claim 16 where said master devices are adapted to query each of said associated subset of slave devices to determine the communications capabilities of each associated slave device.