Abstract:
A wireless hub uses a first processor to communicate with IEDs, uses a second processor to communicate with landline SCADA devices, and uses a third processor to extract, store and exchange messages between SCADA protocols and IED data formats so as to as to permit two way communications between SCADA users and IEDs which are independent of protocol data formats and time of exchange.

Description:
This application is a continuation in part of application Ser. No. 10/405,558 titled A WIRELESS COMMUNICATIONS HUB WITH PROTOCOL CONVERSION filed for Robert W. Beckwith on Apr. 2, 2003 now abandoned which was a continuation in part of application Ser. No. 10/074,110 titled A WIRELESS COMMUNICATIONS HUB WITH PROTOCOL CONVERSION filed for Robert W. Beckwith on Feb. 11, 2002 now abandoned which was a continuation in part of application Ser. No. 09/479,650 titled “EXPANDED CAPABILITIES FOR WIRELESS TWO-WAY PACKET COMMUNICATIONS FOR IEDs” filed by Robert W. Beckwith on Jan. 8, 2000 now U.S. Pat. No. 6,766,143 which claimed the priority date of provisional patent application Ser. No. 60/116,984 filed by Robert W. Beckwith on Jan. 25, 1999 titled “RADIO AS THE MAN/MACHINE INTERFACE FOR AN IED”. The title has been changed. 

   REFERENCES 
   The IEEE 100 dictionary of IEEE standards terms, seventh edition defines the following terms which are used herein: 
   1. “intelligent electronic device (IED) Any device incorporating one or more processors with the capability to receive or send data/control from or to an external source.” 
   2. “supervisory control (1) (supervisory control, data acquisition, and automatic control) An arrangement for operator control and supervision of remotely located apparatus using multiplexing techniques over a relatively small number of interconnecting channels. 
   A form of remote control of remotely located units by electrical means over one or more common interconnecting channels.” 
   Definition of words as used herein:
     1. “bit-stream”: any serial string of binary bits in time sequence.   2. “message”: the bits within a bit-stream that have been assigned a meaning.   3. “data format”: the information required to code and decode messages.   4. “memory format” the information required to place data within an electronic memory and to find data once placed in memory.   5. “routing”: the bits within a bit stream that direct messages in a bidirectional path between two points within a communications network.   6. “DSSS: Direct Sequence Spread Spectrum” The message signal in DSSS transmission is “spread” at baseband and then modulated to the operating frequency (such as the ISM band from 2.4 GHz to 2.4835 GHZ as used by the Beckwith Electric Company M-2901 BLUJAY™ wireless transmitter/receivers). When received the signal is first demodulated to the baseband frequencies and then “despread” to recover the message.   7. “DSSS BPP: Base Band Processor” The Prism II DSSS BBP chip used in BLUJAY™ products sends messages many times at frequencies as high as 11 gigabits per seconds. Various signal failure avoidance techniques are used in repeated transmissions to provide a very high probability that the message components will be received error free each millisecond of message time flow. For that reason BLUJAY™ products use a one megabit per second bit stream transmission rate. An efficient message routing data format ie protocol provides a BLUJAY™ message transmission rate of 0.5 megabits per second.   8. A “protocol” consists of a detailed method of combining messages and routings to form a bidirectional digital communications path between two points.   9. “legacy IEDs” a properly operating IED which is not equipped to communicate in various present day SCADA protocols.   

   PRIOR ART 
   U.S. Pat. No. 5,621,727 by Vaudreuil is an example of network messaging systems using hubs. The Vaudreuil patent will be used herein to describe the differences between the present inventive hub and the network messaging systems of Vaudreuil. 
   Beckwith Electric company (BECO) manufactures M-2901 BLUJAY™ wireless transmitter/receivers. BLUJAY™ devices are used to provide license free bidirectional wireless digital communications between two points. BLUJAY™ devices make no attempt to avoid data crashes other than that described above under “definitions” as provided by Intersil Prism II chip sets used in the M-2901 devices. The M-2901 does not comply with IEEE standard 802.11. 
   It has been demonstrated that BLUJAY™ devices are capable of error free communications with no interference with or by other wireless products in general use in the Industrial, Scientific and Medical (ISM) band. This band is from 2.4 GHz to 2.4835 GHZ as set aside in the USA for unlicensed use of DSSS technology. 
   Wireless BLUJAY™ bit-streams flow at one megabit per second rates. Continuous two way digital communications at 0.5 megabit per second message rates is provided. 
   SUMMARY OF THE INVENTION 
   Unlike the hubs described in the Vandreuil patent referenced above, the inventive hub disclosed herein is for the special purpose of providing SCADA communications to a human operator who has continuous responsibility for the operation of installations such as electric power substations and generating plants. The SCADA communications may use of any one of a variety of protocols in general use. 
   Wireless communications is provided to legacy IEDs within installations such as electric power substations and generating plants by Beckwith Electric BLUJAY™ wireless transmitter/receivers. Protocol conversion is provided between any protocol of an operators&#39; choice to the protocol of BLUJAY™ wireless devices used to read information in each IED memory format. 
   Messages are held for any required length of time by the inventive hub  115 . Messages are exchanged between the hub  115  and the IEDs at rates and times as are fitting to the practical operation of the IEDs. These rates may be as high as 0.5 megabits per second. 
   Operator commands are communicated through the hub to any selected IED within a few tenths of a second. Failure of an IED to communicate is taken as an IED failure and a failure report is generated and sent to the operator. 
   The inventive hub uses one processor acting as a full computer for message storage for each IED, for protocol conversion as required between the BLUJAY™ wireless communications devices and SCADA communications devices and for time buffering of any length required by the operator. For example, historic IED data for a month can be held if required. 
   Two communications processors are provided, one for BLUJAY™ wireless communications with IEDs and a second for SCADA communications with an operator. 
   A user interface port is provided for IED data entry, hub program entry and maintenance communications with the three processors. 
   The foregoing features and advantages of the present invention will be apparent from the following more particular description of the invention. The accompanying drawings, listed herein below, are useful in explaining the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  A block diagram of the inventive hub communicating with an IEDs and with a SCADA user. 
       FIG. 2  The connections of a hub user interface computer to the hub. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The term “SCADA” (for Supervisory Control And Data Acquisition) is used herein to refer to practice as described in reference 2. 
   The term “IED” is used herein to refer to devices within electric utility substations or within industrial complexes which are under operators control using SCADA practices. It is the BLUJAY™ and only the BLUJAY™ protocol that is used to communicate with IEDs by the inventive hub  115  of the present invention. 
   Remarks contained herein concerning BLUJAY™ products and protocols are for information only so as to serve as a limitation for the hub  115  capability in communicating with legacy IEDs. 
     FIG. 1  shows a block diagram of the inventive hub  115 . D processors  130  run continuously using programs for managing data files of information concerning each IED  103  served by hubs  115 . 
   Processors P  120  have 32 bit busses  123 , D  130  have 32 bit busses  132  and S  140  have 32 bit busses  144 . These are each partitioned with first 16 buss bits  0  through  15  used for parallel data transfer via Two Position Parallel Bus Connector (TPPBC)  125 . Processors P  120  have Non-Volatile Memory  129 , D  130  have Non-Volatile Memory  131  and S  140  have Non-Volatile Memory  143 . These non-volatile memories are accessed by the associated processors using the second 16 buss bits  0  through  15 . 
   Using the BLUEJAY™ protocol BECO model M-2910 BLUEJAY™ wireless transceivers  101  using antennae  102  communicate with typical IEDs  103 . IEDs  103  communicate via BLUEJAY™ devices  100  having antennae  105 . Devices  100  may be BECO model M-2910 or selectively may be other BECO BLUEJAY™ devices best suited for particular IEDs. 
   Clock signal generator  150  provides synchronous clock signals on line  151  to processors P  120 , on line  152  to processors D  130  and on line  153  to processors S  140 . 
   Wireless transceivers  101  communicate with P processors  120  via two way serial interconnection  104  and synchronous serial port  127 . P processors  120  exchange data with D processors  130  by parallel transfer through two position parallel bus connectors  125 . Data is sent to and received from IEDs using the BLUEJAY™ protocol. 
   P processors  120  buffer data for purposes of matching data speeds with wireless transceivers  101 , for effecting parallel transfers of data with D processors and if necessary to wait for SCADA communications to end. Direction of parallel transfers is established by enabling line  116  for flow from processor P  120  to processor D  130 . Enabling line  117  establishes data transfer from D processor  130  to P processor  120 . Once a direction is enabled, transfer in the other direction is blocked. 
   S processors  140  provide communications for human operators of electric utility substations or industrial complexes using SCADA practice. Hub  115  provides SCADA communications over circuits  145  connecting via dedicated interface circuits  141  to land line devices used by the SCADA users. 
   Generally SCADA circuits use a dedicated communications network connected between more than one SCADA user. 
   Several SCADA protocols of common choice may be held in S processor memory  143 . If not, a SCADA protocol can be added by the hub user via the hub user interface computer  200  as described under  FIG. 2 . 
   S processor  140  communicates via parallel bus connector  125  to D processor  130 . Connector  125  is two position and can connect S processor  140  to D processor  130  or P processor  120  to D processor  130 . Lines  118  and  119  select the direction of communications between S processor  140  and D processor  130  and operate by the first direction chosen blocking the other direction. Line  136  enables communications between S  140  and D  130  processors and line  121  enables communications between P  120  and D  130  processors. Again operation is on the basis of the first pair of processors enabled blocking the other. Processor S  140  does not communicate with processor P  120 . 
   First 16 lines  0  through  15  on each of 32 bit parallel busses  123 ,  132  and  144  are used for parallel communications via Two Position Parallel Bus Connectors  125 . Second 16 lines  0  through  15  on each of 32 bit parallel busses  123 ,  132  and  144  are used for memory management by the respective processors P  120 , D  130  and S  140 . 
   Again, processors S provide buffering for matching SCADA device data rates, for providing parallel bus communications and if necessary for waiting for P  120  to D  130  communications to end. 
   Processors D  130  and S  140  use multitask programming. The parallel data transfer is programmed in assembly language and takes place well within the time of one task. Data crashes are avoided by alternating assignment of parallel data transfers to tasks of a multitask program. 
   Processor D  130  contains a first field of memory format information for each IED served by hub  115 . This information is that required to convert messages from each IED to a generic form. Selectively this is a binary form identifying such things as:
     1. the IED,   2. the data type, ie Volts, watts, current, VArs etc   3. scaling factors   

   In addition processor D  130  contains a second field of converted information from the generic form into the message format form used in the S  140  processor as required by the SCADA protocol of choice. 
     FIG. 2  shows a user interface computer  200  using a program known as “HUBCOM”. When needed, interface computer  200  can be interconnected with the hub  115  by use of cable  202 . One end of cable  202  is inserted into RS232 port  201  on computer  200  with the other end connected to RS232 port  203  on RS232 paralleling device  204  located within Hub  115 . The RS232 paralleling device  204  connects to asynchronous port  210  on P processor  120  via connection  205 , to asynchronous port  209  on D processor  130  via connection  207  and to asynchronous port  208  on S processor  140  via connection  206 . 
   The hub user will select and activate the SCADA program protocol of choice if contained in non-volatile memory  143  of the S processor  140 . If not available the hub user may enter a SCADA protocol of choice. 
   The hub user can enter memory format and set point information for each IED which in general is expected to differ one from another. 
   The hub user may read IED data stored in the D processor and may communicate with the IEDs in a manner imitating a SCADA user. 
   User interface computer  200  is also used for other maintenance checking of hubs  115 . 
   ADVANTAGES OF THE INVENTION 
   A. Provides SCADA communications to legacy IEDs served by Beckwith Electric BLUEJAY™ wireless devices. 
   B. Stores information including individual IED memory format and setpoint settings as required for proper scaling of data. 
   C. Takes the cost of ethernet out of IEDs. 
   D. Eliminates costs of physical data handling lines within substations and industrial plants. 
   E. Low cost as compared to competitive wired hubs. 
   While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.