Abstract:
A power supply extracts electrical power from the electro-magnetic field surrounding a high voltage power conductor and conditions the derived input power to provide a stable power source for instrumentation and communications equipment. The communications controller is a local network router that routes serial data traffic to selected communication devices such as an instrumentation processor, a power supply processor, or a maintenance port controller. The router forwards the data to other communications equipment and forwards data from the communicating equipment to an external network providing substantially simultaneous communications between the external network and the instrumentation processor, power supply processor and maintenance port controller.

Description:
[0001]     This application claims the benefit of priority of provisional application Ser. No. 60/621,098 filed Oct. 22, 2004. 
     
    
     BACKGROUND  
       [0002]     This invention relates to a communication system. In particular, the communication system can communicate data associated with power transmission lines to remote systems.  
         [0003]     Power line instruments can be mounted on a power line conductor to measure and analyze the values of particular parameters of overhead power line conductors. The performance of the power line may be determined from the values of the parameters. A communication system transmits the values measured by the power line instruments to local ground receiving stations dedicated to those instruments. The data from the various ground stations can be further transmitted to central control stations for analysis of the values of the parameters.  
         [0004]     The values of parameters measured by the power line instruments can provide a measure of the performance of the power line conductor. The parameters associated with each conductor can describe the operational state of the power conductor and include sensing the voltage, current, phase angle, temperature, sag and the other parameters of the associated conductor. The measured quantities are communicated to one or more ground-based processors. Power for the power line instruments can be derived from the electro-magnetic field associated with the power line conductor. When power is conducted through the power line conductor a magnetic field sets up around the conductor. The magnetic field can be used to induce a current and voltage in a power supply. The induced current and voltage can be used for powering the power line instruments including the communication system.  
       SUMMARY OF THE INVENTION  
       [0005]     In one aspect, a power supply controller for an instrument platform associated with a power line conductor includes an extracting means for extracting and outputting power from an electro-magnetic field generated by the power line conductor. A shunt coupled to the extracting means manages the electrical output power of the extracting means. A portion of the outputted power is stored in an energy storage means that provides a direct current (DC). Power conditioning circuitry coupled to the shunt and the energy storage means converts the output power from the extracting means and the DC input from the energy storage means to DC potentials required by circuitry of the power supply controller and the instrument platform. A communications controller is coupled to the power conditioning circuitry to transmit and receive data messages within the instrument platform and with remotely located processors and remotely located instrument platforms.  
         [0006]     The disclosure can be implemented to realize one or more of the following advantages. The electrical instrument platform can be mounted on an energized power conductor and capable of simultaneously measuring and monitoring electrical, thermal and mechanical parameters of the conductor while communicating those values to other similar instruments and also to ground based processors located locally or remotely beyond immediate radio transmission distance. The device has the capability to process and analyze data generated from its own instruments, as well as data received from other such apparatus. The apparatus derives its power from the electro-magnetic field due to current flowing through the power conductor; the disclosure further relates a technique for operating the apparatus using stored energy (batteries) when there is inadequate or no current flow through the conductor.  
         [0007]     One or more implementations include a means for transmitting data to remote systems. The communications may be real time, using wireless radio transceivers, and wireless cellular data technology. Both mechanisms are included in the disclosure, and both mechanisms can be used simultaneously. When fitted with a cell phone transceiver, the device can be used without local ground based equipment. A router system is embodied in the apparatus that manages the data message traffic.  
         [0008]     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will become apparent from the description, the drawings, and the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a functional block diagram of the interconnection of a power supply controller communications control adapter assembly with an external power donut;  
         [0010]      FIG. 2  is a functional block diagram of the power supply controller of  FIG. 1 ;  
         [0011]      FIG. 3  is a functional block diagram of an of a power conditioner;  
         [0012]      FIG. 4  is a functional block diagram of a microcontroller kernel;  
         [0013]      FIG. 5  is an illustration of a power line monitoring system using the present invention;  
         [0014]      FIG. 6  is an implementation of the communications control adapter of  FIG. 1 ;  
         [0015]      FIG. 7  is an implementation of a debug RS232 transceiver port on the communications control adapter of  FIG. 6 ;  
         [0016]      FIG. 8  is a program flow diagram of the power supply controller firmware;  
         [0017]      FIG. 9  is an illustration of a master/slave relationship of the communication protocol. Like reference numbers and designations in the various drawings indicate like elements; and  
         [0018]      FIG. 10  is a perspective view of a power donut in an open position around a power line conductor. 
     
    
     DETAILED DESCRIPTION  
       [0019]      FIG. 10  illustrates an implementation of a toroidal instrument platform  10  that may be disposed about a power line conductor  12 . The instrument platform is used for measuring, monitoring and communicating information associated with the power line conductor. The instrument platform also has provision for receiving a power supply controller and a communication expansion adapter. The power supply controller provides power for the instrument platform and the communications control adapter provides communications between the power donut and a remote processor. A toroid housing  21  is shown in an open position and partially encompassing power line conductor  12 . Housing  21  contains a current transformer  22 , electronic components  24  and a Rogowski coil  23  that may be encapsulated within insulation  25 . Housing  21  is hinged at one section by means of a combination of spring  26  and hinge  8 . A trip mechanism  27  is operably connected with spring  26  to cause halves  21 A,  21 B of housing  21  to come into contact when trip mechanism  27  comes in contact with power line conductor  12 , thus surrounding the power line conductor  12 . Thermal sensor unit  20  attached to one end of spoke  18  is in thermal contact with power line conductor  12  for the purpose of sensing the heat generated by power line conductor  12 . Rogowski-type current sensing coil  23  is a current transducer that permits measurement of current in the power line conductor  12 . Current sensing coil  23  generates current in response to the magnetic field existing around power line conductor  12  and provides indicia of the magnitude of the current passing through power line conductor  12 . Housing  21  can be fabricated from any suitable material, even a conductive material, such as aluminum, without disrupting the transmission of electric power through line  12 .  
         [0020]      FIG. 5  illustrates an implementation of a power line conductor monitoring system  1100  using instrument platforms  1102   a ,  1102   b ,  1102   c  each having a power supply controller and communications control of the present application disposed therein. Instrument platforms  1102   a ,  1102   b  are mechanically mounted on a power line conductor  1104  between two power line transmission towers  1110 ,  1112  and  1112 ,  1114  respectively. Instrument platform  1102   c  is mounted on a power line conductor  1120  between power line transmission towers  1116  and  1118 . In the system illustrated the instrument platforms  1102   a ,  1102   b  are each mounted on the same power line conductor  1104  and instrument platform  1102   c  is mounted on a different power line conductor  1120 . However in other implementations the instrument platforms can be mounted in any arrangement on one or more power line conductors. Each instrument platform includes sensing instruments to determine data parameters associated with the power line conductor on which it is mounted. The power supply controller in each instrument platform extracts power from a magnetic field associated with current flowing through the respective power line conductor  1104 ,  1120 . The extracted power is provided to the instrument platform sensing instruments and the communications control. The communications control of instrument platforms  1102   a ,  1102   b  transmit the data parameters determined by the respective sensing instruments to instrument platform  1102   c . The communications control of instrument platform  1102   c  receives the data parameters from instrument platforms  1102   a ,  1102   b  and transmits the data parameters to a ground-based processor  1124  through a ground-based receiver coupled to a network  1122 . The communications control of instrument platform  1102   c  also can transmit data parameters determined by the sensing instruments of instrument platform  1102   c  to the ground-based receiver. In another embodiment, the data parameters from instrument platform  1102   b  are transmitted to instrument platform  1102   a  that, in turn, forwards those data parameters on to instrument platform  1102   c.    
         [0021]     Thus, in a power line monitoring system using power supply controllers and communication controls of the present invention, each instrument platform can be powered from a power line conductor. Each instrument platform in the system can transmit its own data parameters to another instrument platform or a ground-based processor. Also, each instrument platform in the system can receive data from another instrument platform and transmit that data to a third instrument platform. Hence, only one of a plurality of instrument platforms in the system need be in communication with a ground-based processor and no external power need be provided to the instrument platforms.  
         [0022]      FIG. 1  illustrates a functional block diagram  100  of the interconnection of a power supply controller (PWRSPLY)  102  and a communications control adapter (COMMEXP) Assembly  104  with an external instrument platform (main controller)  106 . The main controller is an instrument platform having mechanical and electrical subassemblies for sensing, monitoring and measuring data parameters associated with a power line conductor (not shown), and is referred to herein as a “power donut” because of its particular shape, described further below. Power supply controller assembly  102  is coupled to a current transformer  108  through a shunt transformer  110 . Power supply controller  102  also is coupled to an energy storage device  112 , such as a rechargeable battery, and to the communications control adapter  104 .  
         [0023]     The communications control adapter  104  is an electrical and mechanical intermediary between the power supply controller  102  and a communications device  114 . Communication device  114  may be one or more wireless communication options disposed on the communication expansion adapter  104 . The communication device  114  includes a 900 MHz Frequency Hopping Spread Spectrum Radio, 2.4 GHz Frequency Hopping Spread Spectrum radio and GSM/GPRS Phone Module. The communications control adapter can provide communication of data from the main controller and power supply controller to external processors (not shown) through the communication device  114 . The external processors can be other instrument platforms, ground-based processors or central control processors that monitor the power line conductor.  
         [0024]     Power supply controller  102  can communicate with the main controller  106  through a network  116 . A microcontroller (not shown) in the power supply controller  102  can run a software program to affect the operation of the power supply controller. Power from power supply controller  102  is provided to the main controller and on to the instrument platform on a line  118 . The power supply controller  102  can include a field update port  120  to receive test and manufacturing updates and software program updates from external devices.  
         [0025]     The function of the power supply controller  102  includes (1) preliminary power conditioning for the main controller  106 , power supply for itself and communications control adapter  104 , (2) communications routing to/from the main controller  106 , (3) communications control of wireless devices  114 , and (4) control of charging a rechargeable battery  112 .  
         [0026]     Current transformer  108  can be disposed around the power line conductor. A magnetic field produced by current flowing in the power line conductor can induce a voltage in the current transformer  108  that may be modified by shunt transformer  110  and provided to the power supply controller  102 . The instrument platform can be powered by coupling with the electro-magnetic field generated when current flows in the power line conductor. The instrument platform is attached directly on the power conductor and measures current and voltage from the electrical and magnetic field surrounding the conductor. The electrical instrument platform includes the rechargeable battery  112  for powering the instrument platform when the current flow, and resultant electro -magnetic field, in the power line conductor is below a first threshold value. When the current flow is above the first predetermined threshold value, the instrument platform can be powered by electromagnetic induction from the power line conductor. When the current flow is above a second threshold value, excess current may be channeled to charge the battery  112 . When a zero current condition persists in the conductor beyond a predetermined time limit, battery control circuitry and/or a software program can reduce the frequency of data transmission from the communications control adapter to the external processors, thus conserving battery power. When battery voltage drops below a predetermined level, all battery-powered transmission may be stopped until the batteries are recharged.  
         [0027]     The interconnection of the power supply controller  102  is now described in greater detail. The interconnections within the power supply controller include: 
        Transformer connector interface  124      Energy storage device (rechargeable battery)  126      communications control adapter  128      Battery disconnect switch  130      Main controller power &amp; I/O (input/output)  132      Test &amp; manufacturing port—field update port  134  
 
 Transformer Connector Interface  124  
       
 
         [0034]     The transformer interface contains signals and potentials including: 
        Output potential from the current transformer  108  to supply the main controller  106  power from the power line conductor being sensed     A signal to control the transformer shunt  110  winding control to attenuate the current transformer  108  output potential 
 
 Energy Storage (Battery) Interface  126  
       
 
         [0037]     The battery interface provides for signals and current flows including: 
        Current to the battery for charging the battery     Current from the battery for powering the instrument assembly     A signal to indicate the battery temperature 
 
 Communications Expansion Interface  128  
       
 
         [0041]     A detailed description of the communications expansion interface is provided below under “The Power Supply Communications Expansion Interface.” 
         [0000]     Battery Disconnect Switch Interface  130   
         [0042]     The Battery Switch interface enables a power down of the instrument platform when line power is not traversing through the power line conductor at a level sufficient to sustain operation of the instrument platform. This functionality can enable the internal battery to maintain a charge when the system is not being used.  
         [0000]     Main Controller Power and I/O Interface  132   
         [0043]     The main controller  106  receives power and control signals from the power supply controller  102 .  
         [0000]     Test and Manufacturing I/O/Field Update Port  134   
         [0044]     The test and manufacturing I/O enables a user to factory program the microcontroller and update factory calibration information stored in a memory of the power supply controller. In addition, when installed in a unit, some of the signals may be route to a port the field update port, that can enable the system to be configured in the field.  
         [0045]     When used as a field update port (FUP), the test and manufacturing interface can be wired using a harness with a reduced number of signals. These signals can be externally available to allow for testing and updates of the firmware (software program) without requiring the power donut assembly to be disassembled.  
         [0046]      FIG. 2  illustrates a functional block diagram  200  of an implementation of a power supply controller  102 . The power supply controller hardware may be partitioned into functional blocks. These blocks include the power conditioner  202 , microcontroller kernel  204 , shunt control  110 , battery charge control  208 , test/manufacturing  134 , main controller interface  212   a ,  212   b  and communications expansion adapter  104 . The functional blocks are described herein below.  
         [0000]     Power Conditioner  
         [0047]     The power conditioner  202  can convert alternating current (AC) input power from the shunt control  110  and the direct current (DC) input from the battery  112  to the DC potentials required within the power supply controller  102 .  
         [0048]      FIG. 3  is a functional block diagram  300  of an implementation of a power conditioner  202 . A battery input (+Vbat) and a primary input (+Vprim) may be input to the Vbat switch circuitry  302 . Vbat switch circuitry  302  can enable the +Vbat signal to supply power to the instrument platform when +Vprim is less than +6V. An output from this circuitry, +VINBATEN, is used to inform the microcontroller  208  ( FIG. 2 ) that +VIN power is being derived from the battery input. +VIN is provided to the communication expansion adapter  104  and the main controller  106 . +VIN may be further filtered using an LC circuit  304  to produce +VINFIL that has reduced high frequency noise.  
         [0000]     +10V Charger (+10VCHG)  
         [0049]     The battery charge control  208  requires approximately +10V that may be derived from the +Vprim signal from the current transformer  110 . Power to the battery charge control  208  may be adjustable under software program control to four different current limit settings and regulated to +10V by a battery charger current limiter and regulator circuitry in the battery charge control  208 .  
         [0000]     Microcontroller Kernel  
         [0050]      FIG. 4  illustrates a functional block diagram  400  of an implementation of a microcontroller kernel  204  ( FIG. 2 ). The microcontroller kernel  204  includes a microcomputer with peripheral support circuitry. The microcontroller kernel includes a microcontroller  402 . In an implementation the microcontroller  402  is a Renesas H8S/2633 microcontroller. The microcontroller  402  can include internal flash memory (256 kbyte) and SRAM (16 kbyte). An external bus  404  also may be provided to allow for bus-oriented devices to be connected to the microcontroller  402  through a high-speed bus.  
         [0051]     External Static Random Access Memory (SRAM)  
         [0052]     External SRAM  406 , which may be organized at 256 kbit×16, can be provided for debug and development as well as external software code/data storage. Data may only be written as words, on even addresses. Code and data constants, which may be stored in the internal flash memory, can reside in External SRAM  406 .  
         [0053]     Serial Electrically Erasable Programmable Memory (EEPROM)  
         [0054]     Two serial EEPROM devices  408 ,  410  may be provided on I2C 412 bus and can be organized as 512×8 bits. A Manufacturing (MFG) EEPROM can be write-able at the factory by assertion of a write-enable signal (EEWREN) available at the test and manufacturing connector  134 . The MFG EEPROM can reside at address  2  (A 0 =0, A 1 =1, A 2 =0) and store information not expected to change in the field. The data can be used by the power supply controller to set thresholds for the minimum power requirements for radio transmission, baud rate configuration, and other parameters.  
         [0055]     Battery Charge Control  
         [0056]     The battery charge control  208  can be used to charge and monitor the status of the energy storage device  112  ( FIG. 1 ). In an implementation, the energy storage device is an integrated Lithium Ion battery pack (2 Cells). Power to the charger can be supplied from the +Vprim ( FIG. 3 ) signal and can be current limited and voltage regulated. The microcontroller  402  can cause the battery charge control  208  to provide different charging rates under program control. The battery charge control can monitor the battery voltage and the battery temperature to regulate the charging of the battery. Charging status signals can be provided by the battery charge control  208  to the microcontroller  402 .  
         [0057]     Transformer Shunt Control  
         [0058]     The current transformer  108  ( FIG. 1 ) provides power to the main controller  106 . The current transformer  108  is wound with a secondary and shunt winding. Transformer shunt control  110  can cause the shunt winding to be shorted and attenuate the power output of the secondary winding. The transformer shunt control thus can limit the maximum voltage output from the secondary winding that may exist under light load conditions or when high current is present on the power conduction line. The microcontroller  402  can monitor the transformer secondary voltage and, in response, control the shorting of the shunt winding by controlling the transformer shunt control winding. In an implementation, an optically isolated triac driving a higher power triac can be used to short the shunt winding.  
         [0059]     Test and Manufacturing Port/Field Update Port  
         [0060]     A test and manufacturing port  134  enables access for the user to factory program the microcontroller  402  internal flash memory and external MFG EEPROM  410 . Boot logic circuitry  414  coupled to the port  134  can enable a user to put the microcontroller  402  into Boot Loader mode when a boot enable (BOOTEN) signal is asserted. A default microcontroller boot mode asynchronous port SCI2 can be connected to the test and manufacturing port  134  to enable RS232 level serial boot loading. Some of the signals to/from test and manufacturing port  134  can be routed to an external field update port  120  ( FIG. 1 ). This may enable operation and field updates of the main controller and microcontroller without disassembly.  
         [0061]     Temperature Sensor  
         [0062]     A temperature sensor  418  can provide the microcontroller  402  with a signal associated with the internal temperature of the power supply controller.  
         [0063]     Power Supply Communications Expansion Adapter  
         [0064]     The communications expansion adapter  104  interface is described in detail below.  
         [0065]     Communications Power Protection  
         [0066]     Communication power protection cam be provided by a current limiting circuit (not shown) to isolate the communications load from the power supply controller. In an implementation, the current limit of the current limiting circuit can be set to approximately 1.0 A to allow for the worst-case continuous load supplied to the communications expansion adapter by the power supply controller.  
         [0067]     Power Supply Communications Expansion Adapter Interface  
         [0068]      FIG. 6  illustrates an implementation of the communications expansion adapter, which includes: 
        Power Supply Controller/Communications Expansion Adapter interface  600      2.4 GHz radio interface  604      900 MHz radio interface  608      GSM/GRPS Cell Phone Module interface  610      SIM Card interface  612      Debug RS232 interface  614  
 
 The communications expansion adapter interface includes: 
    A logic level asynchronous serial interface—H8 SCI1     A logic level SPI to interface which may be configured for Master or Slave—H8 SP13     4 logic level digital outputs     4 logic level digital inputs     An analog input to the H8     And protected +Vin power for the communications devices          
         [0081]     900 MHz Radio  
         [0082]     The 900 MHz radio electrical interconnect  608  is an asynchronous serial interface with logic level signals. Signals may be passed from the power supply controller to the 900 MHz radio through 0 Ω resistors to enable electrical isolation during test and development. The 900 MHz radio  608  interface requires substantially no electrical signal transformation from the power supply controller.  
         [0083]     2.4 GHz Radio  
         [0084]     The 2.4 GHz radio electrical interconnect  604  is an asynchronous serial interface with logic level signals. The interface also can include signals that allow for additional control. The signals may be passed from the power supply controller to the 2.4 GHz radio through 0 Ω resistors to enable electrical isolation during test and development. The 2.4 GHz radio interface  604  requires substantially no electrical signal transformation from the power supply controller.  
         [0000]     In an implementation, the 2.4 GHz radio can be mechanically affixed to the communications expansion adapter.  
         [0085]     GSM G20 Module  
         [0086]     The GSM/GPRS Cell Phone Module  610  can include an asynchronous interface with TTL levels for data/control packets, a master serial peripheral interface (SPI) port for debug information, an inter-integrated circuit (I2C) port for EEPROM configuration and a SIM card interface for GSM identification. The GSM/GPRS Cell Phone module  610  can be mechanically affixed to the communications expansion adapter  104 .  
         [0087]     GSM SIM Card Interface  
         [0088]     The GSM/GPRS Cell Phone module  610  also can be coupled to a SIM card interface  612 , which can enable the module to retrieve GSM system configuration information. Communications expansion adapter  104  can incorporate a SIM connector assembly.  
         [0089]     Debug RS232 Transceiver Port  
         [0090]     A Debug RS232 transceiver port  614  can be used during development to interconnect a host computer to the communications expansion adapter. The debug RS232 port  614  may be used to: 
        Monitor data traffic to and from the communications device  114      Emulate a communications device to allow the power supply controller to communicate with the host computer acting as the data communications equipment (DCE)     Emulate the power supply controller assembly to allow a host to act as the data terminal equipment (DTE)        
 
         [0094]      FIG. 7  illustrates an implementation of a debug RS232 transceiver port.  
         [0095]     Communications Expansion Adapter Power Supply  
         [0096]     The communications expansion adapter power supply  616  ( FIG. 6 ) can be designed to supply power to the installed communications device  114 . Input to the communications expansion adapter power supply may be supplied from the protected +Vin ( FIG. 3 ). The power supply  616  may be configured at time of manufacture for the installed communications device  114 .  
       Power Supply Controller Firmware Design  
       [0097]     Power supply controller operation is controlled by a microcontroller  402  under the control of firmware. The firmware can include two independent executable applications: 
        Application—loaded at the factory or in the field     serial loader—loaded at the factory        
 
         [0100]      FIG. 8  illustrates a program control flow diagram  800 . An initial boot of the microcontroller is performed in the factory at step  802 . The boot-enable (BOOTEN) may be set and the microcontroller reset. The microcontroller may be put into boot loader mode and a serial loader may be installed at time of manufacture using the test and manufacturing port at step  804 . The serial loader may be updated in the field at step  806  with access to the power supply controller. Once installed, the serial loader may be invoked upon cold boots at step  808  to reset the microcontroller. The serial loader can determine when an application is present, validate the application (by a CRC or checksum) and then execute the application. The application is responsible to perform a built-in self test (BIST) at step  810  by an application program interface (API) call. When the BIST passes then program control can continue on to other applications at step  812 .  
         [0101]     The main controller application can be derived from the common code modules and an application layer. The power supply firmware can implement protocol handling functionality compatible with that of the main controller application. The power supply can also support routing of the messages based on the device address information supplied with each command including: 
        PWRSPLY Application     Application Programming interface     Built in Self Test     Hardware Toolkit     Hardware I/O 
 
 The power supply firmware can perform the following functions: 
    Power Management and Control     Battery Charge Control     Support for Multiple radio interfaces     Command/Response Transaction Routing     Alert reporting     User Mode Loader Startup        
 
         [0113]     Power Management and Control  
         [0114]     The power supply firmware can monitor the input power and power conditioning electronics. Status information about the power supply will be periodically transmitted to the main controller. The shunt winding of the power transformer can be controlled by the power supply firmware. The shunt winding may be enabled when the input voltage has exceeded a predetermined threshold.  
         [0115]     Battery Charge Control  
         [0116]     The firmware can monitor status information from the battery charging system to determine available battery power. In an implementation, battery charging at four different charging rates can also be selected programmatically. This call enable the host system to control the charging activity.  
         [0117]     Support for Multiple Radio Interfaces  
         [0118]     The power supply controller, through the communication expansion adapter support, can support different types of radios. The power supply can determine the type of radio connected to the radio interface on power-up by querying the information in MFG EEPROM on the communication expansion adapter. Once the radio type is known, the power supply can correctly handle power up sequences and monitoring of the communication expansion adapter. When a GSM/GPRS Cell Phone is detected, the power supply can handle the additional sequences needed to configure and dial the phone.  
         [0119]     Command/Response Transaction Routing  
         [0120]     The power supply firmware can act as the host to the main controller firmware. The power supply controller may inspect the routing information in any command received by the radio interface or the field update port (FUP) interface. The firmware can determine when the command is for the power supply or the main controller. When a received command is for the power supply controller, the power supply firmware can act on the command directly. When a received command is for the main controller, the power supply can pass the command on for processing. The response to the command may pass through the power supply to the radio interface and back to the ground based host system. The power supply can initiate its own commands to the main controller in order to pass information about the power supply controller to the main controller and also to receive status information from the main controller. The power supply controller may determine the power supply controller address and the address of the main controller from information stored in the power supply MFG EEPROM. The information provides the routing table for the power supply controller, these two device addresses can be set to any 16-bit value. A convention can be used where the power supply controller address is the same as the main controller address plus an offset (for example, main controller address of 0×0100, power supply address of 0×8100). This may simplify tracking of the device address information over many power donut systems.  
         [0121]     Alert Reporting  
         [0122]     The power supply firmware can exchange information with the main controller. When the main controller reports an alert such as a power line conductor measurement from the instrument platform, the power supply can attempt to establish a link with the ground based host system. When a GSM phone is configured on the radio interface then the power supply firmware can attempt to dial a primary phone number to report the alert. Multiple retries may be attempted when the host phone/modem does not answer. When the power supply firmware detects a busy signal at the primary phone number then a connection on a backup phone number may be established. After the power supply establishes a link with the phone, a “wake up” message may be sent to the host system, which will identify the power donut to the host. The host application will then poll for the alert information and take appropriate action(s).  
         [0123]     User Mode Loader Startup  
         [0124]     When the power supply controller receives a command from the radio interface to start the user mode loader, the power supply may first start the user mode loader on the main controller. When the power supply has confirmed that the user mode loader has started successfully on the main controller, the user mode loader can be initiated on the power supply. This protocol also may apply to routing information to allow a ground based host to reprogram either the power supply or main controller.  
         [0125]     Serial Loader Firmware  
         [0126]     Serial loader firmware can enable the user to: 
        Read/Write flash memory     Read/Write SRAM     Read/Write EEPROMS     Execute Code at a selected address        
 
         [0131]     In the factory, at time of manufacture, the first code to be loaded can be the serial loader. The serial loader is instantiated using the boot loader mode protocol available on the H8S through the test and MFG connector. Once the serial loader has been instantiated, a host computer serial port (RS232) can be used to communicate with the unit via the external communications protocol available on the asynchronous radio port. This approach will allow field updates to be made without disassembly of the power donut. The serial loader may be used to load the flash memory and EEPROM memory on the unit. The serial loader can reside in Block  0  of the microcontroller flash memory and may be write-protected at the factory. When the serial loader needs to be updated, the power donut will have to be opened and reprogrammed using the test and MFG connector.  
         [0132]     An example of serial loader commands is shown in Table 1.  
                             TABLE 1                           serial loader Commands                serial loader Command   Brief Description                       Write flash memory   Write flash memory Memory           Read flash memory   Read flash memory Memory           Erase flash memory   Erase flash memory Memory           Write EEPROM   Write EEPROM Memory           Read EEPROM   Read EEPROM Memory           Write RAM   Write RAM Memory           Read RAM   Read RAM Memory           Execute Code   Execute Code                      
 
         [0133]     The serial loader resident in the main controller can reload application code on the main controller in addition to reloading code on the power supply controller module. Therefore routing identification (module ID) will be used to indicate which controller, main or power supply, the host wishes to communicate to.  
         [0134]     Common Code Modules  
         [0135]     The power supply controller application firmware functions can be derived from code modules that are commonly developed for use on the main controller. The common set of functions may be reused in the power supply firmware. The power supply application can be modularized into layers including: 
        Application programming interface     Built-In Self Test     Toolkit     Hardware I/O 
 
 These layers are now described in further detail. 
       
 
         [0140]     Application Programming Interface (API)  
         [0141]     An API can be used to abstract the main application firmware from underlying code modules. This API acts as delineation between the lower level layers of firmware and the target specific application firmware. The power supply controller application may make calls to API layer functions. In an implementation, no direct calls to the underlying toolkit and primitive modules are performed. API functions can return a 16-bit error code after making the call. An example of the API functions are listed in Table 2.  
                         TABLE 2                           API Function Reference            Function Name   Description               API_INITIALIZE_M( )   Initializes the hardware and all API functions       API_BACKGROUND_M   Performs any background operations required by           the API. This function should be called           periodically to learn ensure correct scheduling of           software timers and tasks. This function also           controls a watchdog timer that will reset the           processor in case of errant firmware. The returned           status includes any errors detected by low-level           operations such as ADC buffering.       API_GET_FW_VERSION_M   Returns a string of information that contains the           current firmware revision information.       API_GET_SERIAL_NUM_M   Returns a string of information that contains the           current serial number of the unit.       API_BIST_EXECUTE_M   Executes one or more of the Built-In Self Tests.       API_EEPROM_READ_M   Reads either EEPROM. The manufacturing           EEPROM is located first, the user EEPROM is           located after the manufacturing EEPROM.       API_EEPROM_WRITE_M   Writes either EEPROM. The manufacturing           EEPROM is located first, the user EEPROM is           located after the manufacturing EEPROM. Write           operations to the manufacturing EEPROM will fail           unless an external connection is made to the           EEWREN# signal on the T/M header.       API_ANALOG_READ_M   Reads an analog value from the H8 ADC.       API_DIGITAL_READ_M   Reads a single digital input.       API_DIGITAL_WRITE_M   Writes a single digital output.       API_SERIAL_CONFIG_M   Configures one of the serial ports.       API_SERIAL_GET_RX_SIZE_M   Gets the number of bytes in the serial receive           buffer.       API_SERIAL_CLEAR_RX_M   Empties the serial input buffer.       API_SERIAL_SEND_DATA_M   Sends a block of data via the specified serial port.       API_SERIAL_RECV_DATA_M   Receives a block of data from the specified serial           port.       API_SERIAL_PEEK_DATA_M   Returns data from the serial receive buffer without           removing it. The data remains in the buffer until           RECV_DATA is called.       API_CONFIGURE_TASK_M   Configures one of the two real-time application           tasks.       API_TIMER_CONFIG_M   Configures a software timer.       API_TIMER_CHECK_M   Checks the state of the selected timer.       API_TIMER_WAIT_M   Waits until a timeout of the specified timer occurs.       API_START_LOADER_M   Invokes the User Mode Loader.                  
 
         [0142]     Built-In Self Test (BIST)  
         [0143]     The built-in self-test can verify the operation of hardware elements of the power supply controller. These tests can be run by the application on startup to verify the hardware before attempting to initiate normal operation. An example of the tests performed by the BIST is listed in Table 3.  
                         TABLE 3                           Built In Self Tests            Test   Description               Power   Verifies the power supply voltages       RAM   Performs a write/read sweep test on RAM       flash   Validates the CRC of the application in flash memory       memory       External I/O   Verifies operation of the external digital I/O registers       EEPROM   Validates the CRC of EEPROM data structures, tests write           capability                  
 
         [0144]     Hardware Tool  
         [0145]     The toolkit modules can abstract further details of the hardware environment and perform additional supporting functions. An example of the modules is listed in Table 4.  
                         TABLE 4                           Toolkit Layer Modules            Module           Name   Description               tk_cmdset.c   Implements a function interface for externally available           commands       tk_digital.c   Adds support for external digital latches and registers       tk_eeprom.c   Handles read write sequences to the external EEPROM           memory       tk_hdw.c   Handles system level hardware power up and initialization       tk_rttimer.c   Implements a microcontroller timer based system clock                  
 
         [0146]     Hardware I/O  
         [0147]     Hardware I/O are low-level primitive functions to handle specific hardware elements of the microcontroller kernel and other supporting hardware. An example of the low-level code modules is listed in Table 5.  
                         TABLE 5                           Low Level Primitive Modules            Module           Name   Description               io_adc.c   Support for the microcontroller Analog to Digital           Converter       io_cpu.c   Supports initializing CPU operation in various modes       io_dac.c   Support for the H8 Digital to Analog Converter       io_dig.c   Support for discrete digital inputs and outputs       io_dtc.c   Handles configuration of the H8 Data Transfer controller       io_i2c.c   Implements the I2C protocol using general purpose I/O       io_ints.c   Handles setup and management of interrupt vectors       io_sci.c   Support for any of the H8 Serial communication interfaces       io_spi.c   Support for any of the H8 Serial Peripheral interfaces       io_tpu.c   Support for the H8 16-bit Timer Pulse Units       io_wdt.c   Support for the H8 Watchdog Timer                  
 
         [0148]     Communication Protocol  
         [0149]     An example of a basic format of a communication protocol is shown in Table 6. The format is similar for both commands and responses. In an implementation, the &lt;STX&gt; character is used as a start of frame marker. This is followed by comma separated command or response information. An 8-bit checksum is calculated and appended after the command information. The &lt;EOT&gt; character is used to indicate end of frame.  
                                                   TABLE 6                           Protocol Format            # of   Values                Bytes   Context   ASCII   HEX   Description               1   &lt;STX&gt;   Ctrl B   0x02   Start of Donut Message                       Packet       Max of   AAAA   “1”-   0x30303031-   16 Bit Recipient Device       4       “FFFF”   0x46464646   Address       1   delimiter   ‘,’   0x2C   ASCII comma field                       delimiter       1-m   Field 1           Variable length data                       field       1   delimiter   ‘,’   0x2C   ASCII comma field                       delimiter       1-m   Field 2           Variable length data                       field       1   delimiter   ‘,’   0x2C   ASCII comma field                       delimiter       1-m   Field n           add additional fields                       with delimiter       1   delimiter   ‘,’   0x2C   ASCII comma field                       delimiter       2   CS   “00”-   0x3030-   8 Bit checksum               “FF”   0x4646   calculation       1   &lt;EOT&gt;   Ctrl D   0x04   End of Text Character                 Notes:            1. Parsing of the command response messages may be based on the comma delimiters. In some implementations, the 16-bit device address may not need to contain leading zeros.            2. Numeric values can be represented in HEX format. When using only numbers and uppercase letters, lower case letters will be considered an error in the protocol.            3. No “broadcast” message is supported. The power supply and main controller respond to commands specifically addressed to each device.             
 
         [0150]      FIG. 9  illustrates an implementation of a master/slave relationship of the communication protocol. Commands can be initiated from the master side  902   m ,  904   m ,  906   m  of a communication link  902 ,  904 ,  906 . Power supply controller  908  can act as a slave  902   s  to a ground based host system  912 . Power supply controller  908  also can act as a slave  904   s  to a test system  914  connected through the field update port  916 . In the implementation illustrated, power supply controller  908  acts as a master  906   m  to the slave  906   s  of a main controller  918 . As an example, commands are not initiated from the main controller  918  to the power supply controller  908  because the commands are initiated by the master  906   m  in the communication link  906 . Information passed between the power supply controller  908  and the main controller  918  is initiated by a command from the power supply controller  908 . In an implementation, when parsing incoming commands from the ground system  912 , the power supply controller firmware may first isolate a single command by detecting the start and end of frame markers. When these have been found the power supply can check the checksum value to assure data integrity. The power supply may inspect the 16-bit device address to determine when the command is for the power supply controller  908  or main controller  918 . No action maybe taken when no address match is found and the power supply controller can begin parsing a new command. When a frame has been detected, but the checksum information is invalid, the power supply controller may flush the command from the receive buffer and no response will be transmitted.  
         [0151]     The invention has been described in terms of particular embodiments. Other embodiments are within the scope of the claims.