AU2014201786A1

AU2014201786A1 - Remote telemetry units

Info

Publication number: AU2014201786A1
Application number: AU2014201786A
Authority: AU
Inventors: Mark Davison; Marina Finch; Christopher Fryatt
Original assignee: Metasphere Ltd
Current assignee: Metasphere Ltd
Priority date: 2013-04-02
Filing date: 2014-03-26
Publication date: 2014-10-16
Also published as: GB201305924D0; GB2512598A

Abstract

A remote telemetry unit (10) comprises a housing (11) defining an internal volume, and an electrical connector (13) mounted external to the housing, and having a plurality of electrical connection elements (14, 15) which extend into the internal volume of the housing, the 5 electrical connector (13) being arranged for connection to a plurality of devices external to the remote telemetry unit (10). A controller (19) is located within the internal volume of the housing, and is connected with the plurality of electrical connection elements (14, 15). The controller (19) includes an i/o module (17) connected to receive signals from the electrical connection elements (14, 15) and is operable to set a function for each of the connection 0 elements (14, 15) in dependence upon predetermined set of connection rules. The i/o module is also operable to change such a function of each of the connection elements (14, 15) in dependence upon an external device to be connected with the controller (19).

Description

1 REMOTE TELEMETRY UNITS FIELD OF THE INVENTION The present invention relates to remote telemetry units. BACKGROUND OF THE INVENTION 5 A remote telemetry unit (RTU) is an electronic device that is used to provide telemetry data from sensors and systems to a central measurement and control system. RTUs have many applications, for example in the water supply, sewerage and energy supply industries. In such industries, the RTU may be placed in remote and inhospitable locations. A typical RTU for use in the water supply or sewerage industry would be located in the infrastructure, such .0 as a pumping station or reservoir, for supplying information about the operating conditions of that infrastructure. For example, the RTU can be used to log information generated from a water meter, and to transmit that logged data to a central control and logging system. In addition, RTUs are able to provide a level of intelligence to report by exception. For example, if a sudden drop in water pressure is detected (potentially indicating a major burst .5 in a water pipe), then this can cause the RTU to send an alarm to a receiving system that can then act on the alarm. The use of RTUs in inhospitable conditions renders the units susceptible to water ingress, and so the units are typically provided in sealed housings. Manufacturers provide sealed housings that meet predefined specifications. For example, a housing may be rated for a 20 certain amount of time, for example 4 days, and/or for a predetermined depth of water, for example 4m. An RTU must be connected locally with measurement and recording devices that produce the telemetry data to be stored and transmitted by the RTU. Existing designs of RTU provide a separate external connection socket for each instrument that is to be connected to 25 the RTU. For example, Figure 1 of the accompanying drawings shows an RTU 1 having a housing 2 and a plurality of connection sockets 3. The sockets 3 necessarily provide a physical path between the environment and the internal volume of the housing 2, and so provide a path for water ingress. As the number of measurement devices increases, it is necessary to connect more devices to RTUs. It is not economically viable to provide a large 30 number of RTUs with an increased number of measurement units.

2 Accordingly, existing RTU designs provide an increased number of connection sockets 3. However, this results in an increased risk of water ingress into the housing. Also, unused connectors need to be protected from the environment, which is normally achieved by the use of protective caps. These caps can be left off by users/installers, which often leads to 5 damaged units. It is, therefore, desirable to provide a design of remote telemetry unit that overcomes the drawbacks of the previously considered designs. SUMMARY OF THE INVENTION According to one aspect of the present invention, there is provided a remote telemetry unit .0 comprising a remote telemetry unit comprising a housing defining an internal volume, an electrical connector mounted external to the housing, and having a plurality of electrical connection elements which extend into the internal volume of the housing, the electrical connector being arranged for connection to a plurality of devices external to the remote telemetry unit, and a controller located within the internal volume of the housing, and .5 connected with the plurality of electrical connection elements, wherein the controller includes an i/o module connected to receive signals from the electrical connection elements and operable to set a function for each of the connection elements in dependence upon a predetermined set of connection rules, and operable to change such a function of each of the connection elements in dependence upon an external device to be connected with the 0 controller. In one example, the i/o module is configurable by software. In one example, the i/o module is operable to connect any one of the plurality of electrical connection elements to any one of a second plurality of connections of the controller. In one example, the i/o module is operable to connect any one of a plurality of external 25 devices to the controller. In one example, each of the connection elements has a respective predefined range of functions from which the i/o module is operable to set for the connection element concerned. In such an example, the connection elements are arranged in functional groups according to the predefined range of functions assigned to each of the connection elements.

3 In one example, the connection elements are arranged in predetermined groups, and the i/o module is operable to connect any one of the connection elements in a predetermined to any one of a predetermined number of connections of the controller. According to another aspect of the present invention, there is provided a remote telemetry 5 system comprising a remote telemetry unit according to the first aspect of the present invention, and a plurality of external telemetry devices, each of which is connected with the electrical connector in parallel with one another. In one example of such a system, the i/o module of the remote telemetry unit is operable to connect only one of the plurality of external telemetry devices to the controller at any one .0 time. In another example of such a system, the i/o module of the remote telemetry unit is operable to connect more than one of the plurality of the external telemetry devices to the controller at any one time. BRIEF DESCRIPTION OF THE DRAWINGS .5 Figure 1 is a schematic view of a previously considered remote telemetry unit; Figure 2 is a cross-sectional schematic view of a remote telemetry unit embodying an aspect of the present invention; Figure 3 is a functional block diagram illustrating a first example of the unit of Figure 2; and Figure 4 is a functional block diagram illustrating a second example of the unit of Figure 2. 20 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 2 illustrates a remote telemetry unit (RTU) 10 embodying the present invention. The RTU 10 comprises a housing 11 which defines an internal volume. The housing 11 is sealed against water ingress, according to defined standards, so that the internal volume is protected from conditions external to the RTU 10. The housing 11 is preferably of a non 25 electrically conductive plastics material, such as ABS. The housing 11 contains telemetry and data transmission circuitry 12 (not illustrated in detail for the sake of clarity) which uses a single external connector 13 to provide input and output 4 communications with devices and systems outside of the unit 10. The external connector 13 is connected to the circuitry 12 by way of a connection 14. In some examples, an additional external connector may be provided for dedicated use by radio frequency transmission and reception circuitry within the RTU 10. 5 The provision of a single connector 13 for connection to a plurality of external measuring and recording devices reduces the likelihood of water ingress into the housing, since the number of paths for such water ingress has been reduced. Figure 3 illustrates parts of the RTU 10 that enable the provision of a single external connector 13. The connector 13 is provided with a plurality of connection elements 15. The .0 connection elements may be provided by pins or sockets, or a combination of the two. The connection 14 is a multi-strand cable that connects the connection elements 15 of the connector 13 to a controller 19 for bidirectional communication therebetween. The controller 19 includes an i/o module 17 for controlling communication with the connection elements 15. The controller 19 is provided with a storage device 21 for storage of data. Other aspects of .5 the circuitry of the RTU, such as a radio frequency unit, are not shown for the sake of clarity. The i/o module 17 operates to define the function of each of the connection elements 15, and to change those functions in dependence upon the external device with which the RTU 10 is connected. This functional definition of the connection elements allows a single connector to be used with multiple different external devices. 20 In a preferred example, multiple external devices are wired together into the single external connector 13, using a single removable plug located in the connector 13. In order to connect a particular one of the various external devices to the controller 19 of the RTU 10, the i/o module 17 defines the function of each of the connection elements as appropriate to the external device concerned. 25 For example, each connection element may be able to be defined as one of a number of different functions: analogue input or output, or digital input or output. The controller 19 controls the i/o module 17 digitally, and determines the switching paths in the i/o module 17. The switching paths in the i/o module 17 are configured such that in an 5 ON or 'selected' state a given path has very low electrical resistance, and so is suitable for connection to a low frequency analogue signal source, or to a digital signal source. In one example, the i/o module 17 routes digital signals to a digital module of the controller 19 for storage of the digital data routed through the i/o module 17. The controller 19 is then 5 operable to read the stored data values from the digital module. Figure 4 illustrates an alternative example in which the i/o module 17 is provided to connect any one of the connection elements 15 to any one of a plurality of input/output connections of the controller 19. The i/o module 17 receives control signals 20 from the controller 19 in order to determine which connections should be made between the connection elements 15 .0 of the connector 13 and the controller 19. In one example, each connection element 15 has several configuration options. One possible set of configuration options is shown below: 10_PIN 1 Active Loop 1, Ground, Supply 1, D01+ 10_PIN 2 Active Loop 2, Ground, Supply 2, D01 10_PIN 3 Always Ground 10_PIN 4 DI, Cl, Al, Ground, UART (TX) 10_PIN 5 DI, Cl, Al, Ground, UART (RX) 10_PIN 6 DI, Cl, Al, Ground, Passive loop, D02+ 10_PIN 7 DI, Cl, Al, Ground, Passive loop, D02-, HART 10_PIN 11 DI, Cl, Al, Ground where DO is a digital output, DI is a digital input, Al is an analogue input, Cl is a clock signal, UART is a universal asynchronous receiver/transmitter connection, and HART is a highway 15 addressable remote transducer protocol connection. Depending upon the particular use of the device, and on the particular devices being attached to the RTU, the i/o module 17 may adhere to a set of predetermined rules concerning the connections. For example, the following rules may apply: 1) 10_PIN 6 cannot be used as an analogue input unless 10_PIN 11 is set as ground; 20 2) If 10_6 is a passive loop 10_11 must be ground; 3) If IOPIN2 is used as Active loop 2, 10_PIN 4 must be ground; 6 4) If IOPIN1 is used as Active loop 1, 10_PIN 5 must be ground; 5) For HART Supply 1 or Supply 2 must be used; 6) 10_PIN1 and IOPIN2 must work together for a single Digital Output (DO1); 7) 10_PIN6 and IOPIN7 must work together for a single Digital Output 2 (D02); 5 8) IOPIN4 and IOPIN5 work together to create a UART channel; 9) An analogue channel can be linked to a Supply pin; and 10) All pins can be placed in high impedance (HiZ)/unused mode. Such rules are determined by the devices being connected and the type and purpose of the RTU. 0 In some examples, an additional external connector may be provided for dedicated use by radio frequency transmission and reception circuitry within the RTU 10.

Claims

1. A remote telemetry unit comprising: a housing defining an internal volume; an electrical connector mounted external to the housing, and having a plurality of 5 electrical connection elements which extend into the internal volume of the housing, the electrical connector being arranged for connection to a plurality of devices external to the remote telemetry unit; and a controller located within the internal volume of the housing, and connected with the plurality of electrical connection elements, .0 wherein the controller includes an i/o module connected to receive signals from the electrical connection elements and operable to set a function for each of the connection elements in dependence upon predetermined set of connection rules, and operable to change such a function of each of the connection elements in dependence upon an external device to be connected with the controller. .5

2. A remote telemetry unit as claimed in claim 1, wherein the i/o module is operable to connect any one of the plurality of electrical connection elements to any one of a second plurality of connections of the controller.

3. A remote telemetry unit as claimed in claim 1 or 2, wherein the i/o module is operable to connect any one of a plurality of external devices to the controller. 20

4. A remote telemetry unit as claimed in claim 1, wherein each of the connection elements has a respective predefined range of functions from which the i/o module is operable to set for the connection element concerned.

5. A remote telemetry unit as claimed in claim 4, wherein the connection elements are arranged in functional groups according to the predefined range of functions 25 assigned to each of the connection elements.

6. A remote telemetry unit as claimed in claim 1, wherein the connection elements are arranged in predetermined groups, and the i/o module is operable to connect any one of the connection elements in a predetermined to any one of a predetermined number of connections of the controller. 8

7. A remote telemetry system comprising a remote telemetry unit as claimed in any one of the preceding claims, and a plurality of external telemetry devices, each of which is connected with the electrical connector in parallel with one another.

8. A remote telemetry system as claimed in claim 7, wherein the i/o module of the 5 remote telemetry unit is operable to connect only one of the plurality of external telemetry devices to the controller at any one time.

9. A remote telemetry system as claimed in claim 7, wherein the i/o module of the remote telemetry unit is operable to connect more than one of the plurality of the external telemetry devices to the controller at any one time.