MXPA99001132A - Automated communication of electricity meter data - Google Patents

Abstract

An electricity meter which, in one embodiment, includes a microcomputer coupled to both a liquid crystal display (LCD) and anoptical port. The LCD includes an on board controller and an LCD random access memory (RAM), and in accordance with the present invention, the microcomputer is programmed to communicate the contents of the LCD RAM to the optical port during selected times of meter operation. Generally, and in an exemplary embodiment, when the LCD RAM data is updated by the microcomputer during meter operation, the microcomputer communicates such updated data to the optical port. In one specific implementation, a user selectable flag may be set to 1 or 0. If the user sets the flag to 0, then the communications feature is not enabled. If the flag is set to 1, then the communications feature is enabled. In operation, and upon receipt of a display quantity command, the microcomputer writes data to the LCD RAM. The microcomputer then checks whether the communications feature is selected (i.e., whether the flag is set to 0 or 1), and if the feature is not selected, processing proceeds as is known. If the flag is set to 1, then the microcomputer reads the data stored in the LCD RAM and communicates such data to the optical port.

Description

AUTOMATIC COMMUNICATION OF ELECTRICITY MEASUREMENT DATA FIELD OF THE INVENTION This invention relates generally to the measurement of electricity, and more particularly, to the automatic testing of electricity meters.

BACKGROUND OF THE INVENTION Since the data collected by an electricity meter to measure the energy consumption of a load are used for billing purposes, it is important to ensure the accuracy of such data. With the latest electricity meters, which include digital signal processors and microcomputers, the amount of data collected and the complexity of measurements made has increased. For example, electricity meters can present hundreds of different quantities, and many of the quantities can be presented in different formats (for example, different numbers of digits and decimal point locations). The verification that each quantity is formatted and presented properly, with the correct advertisers, is a time-consuming task. One of the many characteristics to measure the consumption of time to test is the operation of the presentation of the meter. Measurement data is typically not stored in the meter's memory in engineering units (for example kilowatts / hours). Rather, the measurement data is stored in the meter's memory in values proportional to the engineering units. When the meter presents a value, the quantity is recovered from the meter memory, scaled with an appropriate scaler and then the corrected segments on the screen (for example, an LCD) are "illuminated" to show the quantity. In addition, the appropriate corresponding data annunciators (for example, kWh for the kilowatts / hour) are also "illuminated". In the past, when testing the meter's display, it was known to provide a meter with known inputs and then verify if the meter had the correct amounts. An operator typically sees the screen and since the screen scrolls, the operator describes the amount displayed in a note. The quantities written by the operator are then manually compared to the expected quantities, and if the quantities correspond, then the meter is considered to have passed the test. Of course, the requirement of an operator to write the amounts presented, particularly for a meter that presents hundreds of quantities, is a time-consuming task. It may be desirable to provide a more automatic meter test to substantially eliminate the requirement that the measured quantities be written by an operator when testing the meter display. It may also be desirable to provide such an automatic test without significantly increasing the manufacturing cost of a meter, in terms of both labor and materials.

COMPENDIUM OF THE INVENTION These and other objects can be achieved through an electricity meter, which, in one embodiment, includes a microcomputer coupled to both an LCD screen and an optical port. The LCD screen includes an internal controller and an LCD random access memory (RAM), and in accordance with the present invention, the microcomputer is programmed to communicate the contents of the LCD RAM to the optical port during selected times of meter operation. . Generally, and in an illustrative embodiment, when the LCD RAM data is updated by the microcomputer during the operation of the meter, the microcomputer communicates said updated data to the optical port. In a specific implementation, a selectable user signal can be set to be 1 or 0. If the user sets the signal to 0, then the communications feature is not enabled. If the signal is set to 1, then the communication feature is enabled.

During operation, and upon receiving a presentation quantity command, the microcomputer writes the data to the LCD RAM. The microcomputer then rectifies if the communication aspect is selected (ie, if the signal is set to 0 or 1), and if the feature is not signaled, the processing proceeds as is known. If the signal is set to 1, then the microcomputer reads the data stored in LCD RAM and communicates said data to the optical port. By programming the meter computer as described above, a test device can be coupled to the optical port during normal operation of the meter. The device can then passively wait to receive the data communicated to the port through the microcomputer, and comparing the received bit pattern with the expected bit pattern (i.e., the bit pattern that will be stored in LCD RAM under the predetermined conditions ), the test device can verify the proper operation of the meter. In addition, and using the operation described above, the meter does not have to operate in a special mode of operation during communication to avoid a message in communication progress (for example bUSy). In addition, the test device does not need to know how the LCD RAM is updated. For example, in some known meters, the display travel time is programmable, and in order to correctly read the LCD RAM the test device needs to figure out the travel time and then read the LCD RAM at an appropriate time for each element of presentation. With the operation described above, the test device simply waits passively to receive data communicated thereto through the optical port. Also, with some known meters, communications with the meter through the optical meter port are not distributed during the test operations. However, with the meter described above, such communications may occur during all modes of operation, including the test mode. In addition, and with the meter described above, the presented meter data (ie, the input data and the programmed data) are communicated in a formatted manner (ie, in the format required to present the data via the LCD). ) instead of a raw, unformatted way, where the data is stored internally in the meter's memory.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram in an electronic energy meter. Figure 2 is a flow diagram illustrating the operation of the microcomputer shown in Figure 1 according to one embodiment of the present invention.

DETAILED DESCRIPTION Figure 1 is a block diagram illustration of an illustrative electronic energy meter 10 which, for example, is commercially available from General Electric Company, 130 Main Street, Somersworth, N.H. 03878, and is generally referred to as the KV meter. The KV meter can be modified as described below in more detail to provide an even more automatic test. Although the apparatus and methods herein are described herein in the context of an electronic electricity meter, it should be understood that the present invention is not limited to practicing with any other particular meter. The present invention can be used in conjunction with other microcomputer-based meters. Referring now specifically to Figure 1, the meter 10 includes voltage sensors 12 and current sensors 14. Sensors 12 and 14, during operation, are typically coupled to power lines supplying power to the site where the meter is located. The sensors 12 and 14 are coupled to an analog to digital (A / D) converter 16, which converts the analog input voltage and the signal current to digital signals. The output of the converter 16 is provided to a digital signal processor (DSP) 18. The DSP 18 supplies the microcomputer 20 with digitized measurement quantities, for example, V2H, l2H. The microcomputer 20, using the measurement quantities supplied by DSP 18, performs additional calculations and measurement functions. The DSP 18 may be, for example, a commercially available processor with the model number TMS320 from the Texas Instruments Company, P.O. Box 6102, Mail Station 3244, Temple, TX 76503, modified to perform measurement functions. The microcomputer 20 is coupled to a liquid crystal display 22 to control the display of various selected measurement quantities and an optical communication port 24 to allow an external reader or tester to communicate with the computer 20. Port 24 may be the Well-known OPTOCOM ™ port of General Electric Company, 130 Main Street, Somersworth, NH 03878, which is in accordance with the optical port type II ANSI. The microcomputer 20 can also generate additional outputs 26 used for several other functions well known in the art. The microcomputer 20 can be, for example, an 8-bit microcomputer commercially available from Hitachi America, Inc., Semiconductor & I.C. Division, Hitachi Plaza, 2000 Sierra Point Parkway, Brisbane, CA 94005-1819, modified to perform measurement functions. The microcomputer 20 is also coupled to an input / output (I / O) board 28 and a function or high function board 30. The DSP 18 also outputs directly to the high-function board 30. The microcomputer 20 is also coupled , through a control busbar 32, to an electrically erasable programmable read only memory (EEPROM) 34. The board I / O 28 and the high function board 30 are also coupled, through the busbar 32, to the EEPROM 34. Backup power is supplied to the meter components described above through a battery 36 coupled to a wide scale power supply 38. During normal operation, when the backup power is not required, the power It is supplied to the meter components of the power lines through the power supply 38. Many functions and modifications of the components described above are well understood in the measurement technique. The present application is not directed to such well-known functions and modifications. Rather, the present invention is directed to methods and apparatus for testing the measurement display as described below in detail. Furthermore, although the methods and apparatuses are described later in the hardware environment shown in relation to Figure 1, it should be understood that said methods and apparatuses are not limited to practicing in said environment. The methods and apparatuses of the invention can be practiced in many other environments. Furthermore, it should be understood that the present invention can be practiced with many alternative microcomputers, and is not limited to being practiced together with the microcomputer 20. Therefore, as used herein, the term microcomputer is not limited to representing just those integrated circuits referred to in the art as microcomputers, but broadly refers to microcomputers, processors, microcontrollers, application-specific integrated circuits, and other programmable circuits. With respect to the LCD 22, which in the illustrative embodiment includes an internal LCD controller (eg, a Hitachi H8 / 3834 series controller) with a random access memory (RAM), said controller illuminates segments of the screen 22 based on data written to a specific segment of RAM. For example, if a particular RAM location is set to 1, then the corresponding segment is illuminated. Otherwise, the segment is not illuminated. RAM can be read from and written as is well known in the art. During a communications session, the LCD screen 22 will typically present an indication that such a session is occurring, for example, the display 22 may display a bUSy (busy) message. Therefore, when reading the RAM of the LCD during a communication session, the reading of the pattern will be that required to present the communication message. In accordance with the present invention, and to provide a more automatic test of meter operations, the microcomputer 20 is programmed to communicate the contents of the LCD RAM to the optical port 24 during selected times of the meter operation. In general, and in an illustrative embodiment, when the LCD RAM data is updated by the microcomputer 20 during the meter operation, the microcomputer 20 communicates said updated data to the optical port 24. More specifically, the microcomputer 20 is programmed to communicating data to the communication port 24 at least after the occurrence of a group of predetermined conditions. In one embodiment, the conditions are that a presentation quantity command is received by the microcomputer 20, that the data is written on the screen 22 by the microcomputer 20, and that a signal in the memory of the microcomputer has a first state, for example, a value of 1. In the illustrative mode, said data is communicated to port 24 through the microcomputer 20 asynchronously to 9600 baptisms. In a specific implementation, and referring to Figure 2, which is a flowchart 50 illustrating the operation of the microcomputer 20 according to an embodiment of the present invention, a communication feature signal selectable by the user, , you can rely on 1 or 0. The value of the signal is stored in a predesignated location in the computer's memory. If the user sets the signal to 0, then the communications feature is not enabled. If the signal is set to 1, then the communications feature is enabled. The signal is typically set by an operator and once set, does not need to be re-set unless the operator wishes to enable or disable the feature, after reprogramming, or after a power interruption. During operation, and after receiving a presentation quantity command 54, the microcomputer 20 writes the data in the LCD RAM 56. The microcomputer 20 then checks 58 if the communications aspect is selected (i.e., if the signal is set to 0 or 1), and if the signal is set to 1, then the microcomputer 20 reads the data stored in the LCD RAM and communicates, 60, said data to the optical port 24. The routine is then taken out, 62. If the aspect is not selected (ie, signal = 0), the routine is pulled out, 62, and processing proceeds as is known. In a specific implementation, the communications aspect can be easily disabled by cleaning the signal, and the feature is always disabled after the meter is reprogrammed or when the energy is cycled. The processing described above only enables communications of the LCD RAM data to the optical port 24 when an amount is updated in the LCD RAM. It is contemplated that the LCD RAM data may also be communicated to the optical port 24 under other conditions, such as after the occurrence of real times such as the end of a demand interval, if desired. By programming the computer 20 as described above, a test device can be coupled to the optical port 24 during the test operation. The device can then passively wait to receive the data communicated to port 24 through the microcomputer 20, and by comparing the received bit pattern with the expected bit pattern (i.e., the bit pattern that will be stored in the LCD RAM). under the predetermined conditions), the test device can verify the proper operation of the meter. Using the operation described above, the meter does not have to operate in a special mode of operation during communication to avoid a message communication in progress (for example, bUSy). In addition, the test device does not need to know how the LCD RAM is updated. For example, in some known meters, the display travel time is programmable, and in order to correctly read the measurement data, the test device needs to find out the travel time and then read the data at an appropriate time for each presentation element. With the operation described above, the test device simply passively waits to receive the data communicated thereto through the optical port 24. Also, with some known meters, communications with the meter through the optical meter port are not distributed during the test operations. With the meter described above, however, such communications may occur during all modes of operation, including the test mode. In addition, and with the meter described above, the meter data that is presented (ie, the input data and the programmed data) are communicated in a formatted manner (ie, in the format required to present the data on the screen). 22) instead of a raw, unformatted way where data is stored internally in the meter's memory. From the foregoing description of the various embodiments of the present invention, it is clear that the objects of the invention are achieved. Although the invention has been described and illustrated in detail, it should be clearly understood that it is intended only by way of illustration and example and can not be taken in a limiting manner. Accordingly, the spirit and scope of the invention will be limited only by the terms of the appended claims.

Claims (14)

1. - An electricity meter for measuring the energy consumption of a load, comprising: voltage and current sensors to generate signals representative of the current and voltage in the load; a microcomputer coupled to the sensors, said microcomputer comprising a memory having at least one memory location designated for the storage of at least one signal; a screen coupled to the microcomputer to present measurement values; and a communication port coupled to the microcomputer; the microcomputer programmed to communicate data to the communication port based on the state of the signal.

2. A meter according to claim 1, wherein the communication port is an optical communication port.

3. A meter according to claim 1, wherein if the signal is set to a predetermined value, and after receiving a command to present a quantity, said microcomputer communicates the data to the port.

4. A meter according to claim 1, wherein to communicate the data to the communication port, the microcomputer is programmed after receiving a command amount of presentation, write the data on the screen and check the status of the signal .

5. A meter according to claim 4, wherein the microcomputer is also programmed to read the data written on the screen and communicate the data read to the port if the signal has a first state.

6. A method for operating a microcomputer of a meter that includes voltage and current sensors to generate signals representative of the current and voltage in the load, the microcomputer coupled to the sensors and including a memory that has at least one memory location designated for the storage of at least one signal, the meter further includes a screen coupled to the microcomputer to present the measurement values and a communication port coupled to the microcomputer, the method comprising the steps of: after receiving a presentation quantity command, write the data on the screen; verify the state of the signal, and if the signal has a first state, read the data written on the screen and communicate at least the written data to the port.

7. A method according to claim 1, wherein if the signal has a second state, then data communication to the port is not continued based on the presentation quantity command.

8. A method according to claim 6, wherein the communication port is an optical communication port.

9. An electricity meter to measure the energy consumption of a load, which includes: a microcomputer; a screen coupled to the microcomputer to present measurement values; and a communication port coupled to the microcomputer; the microcomputer programmed to communicate data to the communication port at least after the occurrence of a group of predetermined conditions, at least one of the conditions being that the data is written to the screen.

10. A meter according to claim 9, wherein the group of predetermined conditions further comprises the condition of a presentation quantity command is received by the microcomputer.

11. A meter according to claim 9, wherein the microcomputer further comprises a memory having at least one memory location designated for the storage of at least one signal.

12. A meter according to claim 11, wherein the group of predetermined conditions further comprises the condition that the signal has a first state.

13. A meter according to claim 9, wherein the communication port is an optical communication port.

14. A meter according to claim 9, wherein to communicate the data to the communication port, the microcomputer is programmed to read the data on the screen and communicate the data read to the port.