Patent Publication Number: US-8126964-B2

Title: Method for displaying data in an industrial control system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Swedish patent application 0402823-9 filed 14 Nov. 2004 and is the national phase under 35 U.S.C. §371 of PCT/SE2005/001727 filed 14 Nov. 2005. 
     TECHNICAL FIELD 
     The present invention is concerned with accessing and distributing technical data in a computerised system such as an industrial control system. In particular it is concerned with accessing and distributing data provided by a server process, such as a web server, to a client process. The invention is also advantageously applicable to small computing devices which may have relatively reduced display, memory and processing capabilities. 
     BACKGROUND ART 
     Ordinary computer systems and networked computers are often provided with technical support for application problems, network problems and so on by means of remotely located technical support specialists. Typically a remotely located Help Desk specialist may be contacted by phone, e-mail, intranet or the Internet etc. to assist with a problem of a computerised system. Certain software applications familiar to those skilled in the art of Local Area Networks (LANs) are readily available so that a technical specialist at a remotely located Help Desk may look at a display running on the problematic computer system and input selections or commands as though the specialist were present in person. However, such specialists are only be able to assist with problems related to a specific LAN. In addition, applications sometimes called “remote control” software such as PC anywhere (TM Symantec) may effectively copy and transmit screen images and keyboard inputs from a remote user, however this can also place high demands on communication bandwidth and processing power. 
     The security of remote connections is a challenging issue. One method to enable secure sharing between different machines has been the use of Virtual Private Networks, VPNs. However, for many organisations these have proved to be rather complex for ordinary pc users to configure and set up. VPNs have also required a considerable communication bandwidth to accommodate functions such additional layers required for security, as well as the data or payload elements. Such heavy requirements on bandwidth, and also on processing power, make such applications unsuitable for smaller or portable computing devices with reduced display, memory and processing capabilities that are available to users in an industrial installation. 
     SUMMARY OF THE INVENTION 
     The aim of the present invention is to remedy one or more of the above mentioned problems. 
     It is an aim of the invention to provide a system and method for a third party to provide maintenance service for an electrical power generation, transmission and distribution system to a Utility or other operator of a power system. This and other aims are fulfilled by the present invention according to a method and a system. In addition, further and advantageous aspects of the invention are provided by a graphical user interface, and a computer program and a computer program product. 
     In a first aspect of an embodiment of the invention a method for sharing data provided by a server process of an industrial control system to a client process running on a user machine of a first user, wherein the session is logged by said server process, and by the process of determining that said first user makes a selection to distribute or share said data of said client process with at least one second user, and by retrieving an address for the at least one other user, and by opening a channel and providing the same said data from said client process to a user machine of the at least one second user. The invention may be summarily or simply described as a means for communicating technical data provided by a server to a first client and distributing it to a client of a second or other user. 
     A first arrangement of an embodiment of the invention comprises two different users both accessing data provided by the same server, preferably a web server, from two different machines or workstations. Simply put this may be described to mean that web pages, for example, displayed by a client process and viewed by a first user may be automatically loaded on a client process for another user, so that each of the two users may examine the same page. Collaboration between different users is provided, enabled and supported by the invention in a way which requires a minimum of additional communication bandwidth and a minimum of additional computer programs. It may also be carried out largely independent of different device types, for example by using technical formats such as HTML or XML, XSL structured text documents and the like which may be converted to suit device based technical requirements into WAP or WSL, WDL or other formats. A particularly useful example of formatting and format conversion is to suit potentially limiting factors common with small, portable computer-equipped devices, PDAs, mobile phones and the like, technical factors such as display size, graphical resolution, available memory, available processing power. 
     The principle advantage of an embodiment of the present invention is that all the necessary information about what is shown on the client of the first user, which has already been handled at one time by the server, is therefore available for distribution, or for retrieval and distribution, making this information shown on a client screen of the first user to be shared and displayed to a display for one or more second users. The requirement for pre-installed software on the client may in practice be eliminated, as it is only a thin client such as a web browser client that is required. Software readily available on any computing platform in other words. Data is shared between users whilst minimising used network bandwidth and use of system resources (especially on the client). Bandwidth requirements are further reduced because the sharing may also preferably be carried out asynchronously. 
     In this embodiment of the invention data sharing between users is provided by means of reduced bandwidth requirements, no extra client software requirements, low use of system resources, and where the only additional device or resource required is means to access a session database from a server process or application according to another aspect of the invention, that enables asynchronous application sharing. 
     Data that is provided by the server process to a client process is logged. The same data can also be sent to another user at the same time, or retrieved and sent at a later time. This minimizes the traffic from the client/user and the workload on the client device. 
     Another advantage is that sharing is enabled for a device that may have limited computing resources, meaning for example limited communication bandwidth, limited processor power, limited graphics capability. Thus it is very suitable for a wireless setting employing various mobile devices, various computer-equipped devices, such as portable computers, PDAs, combined computing device/mobile telephone and the like, most of which are limited in their bandwidth, data storage capacity and amount of processing power available to handle extra applications and/or computer programs. Providing data and sharing data to such computer-equipped devices or phones is simplified by re-formatting the shared data where necessary to comply with technical requirements of a WAP browser or similar browser or thin client adapted for use on a small device or mobile phone. 
     This is a great advantage within the area of sharing data handled by an industrial control system. A first user may share information displayed on his computer or PDA etc with a second user, who may be a technical expert, a Help Desk person, a colleague and so on, so as to explore or discuss a technical issue concerning a device or process or product. In this way, technical assistance for monitoring or maintenance of devices or processes in an industrial installation may be more easily carried out, even in situations where the computing devices used in the field may have limited display, memory and processing power. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the method and system of the present invention may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings wherein: 
         FIG. 1  shows a schematic block diagram of a system for sharing data provided by a server process of an industrial control system, according to an embodiment of the invention; 
         FIG. 2  shows a schematic flowchart for a method according to an embodiment of the invention; 
         FIG. 3  shows a schematic flowchart for a method according to another embodiment of the invention; 
         FIG. 4  shows a schematic display and selection means according to another embodiment of the invention; 
         FIG. 5  shows a schematic display with means to identify another user or users to share screens with; 
         FIG. 6  shows a schematic display with means to allocate privileges for another user or users that will share screens. 
         FIG. 7  shows a schematic display with means to request technical assistance for a device, process or system in an industrial installation, according to another embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A user in an industrial installation may require technical information from a technical specialist to assist him or her with a particular equipment or process or service. To obtain more technical information for an equipment or system a user can, by using the method and system of an embodiment of the invention, share the data displayed on his/her workstation with another person, in this example, contact a maintenance specialist, or other technical support specialist or manufacturers specialist. Thus a user, who may be any operator, technician, maintenance person, engineer or other authorised person in the industrial installation may require assistance in order to carry out a technical action including any of:
         monitor a equipment, process or system,   inspect a maintenance or event log for an equipment or process,   produce a maintenance report generally,   produce a general operations report,   produce a maintenance report about a specific equipment, process or system,   analyse a report for a device, process or system,   analyse a report on a specific event or alarm,   produce a report on a specific event or alarm,   perform a diagnostic action for a device, equipment or system,   order service or spare parts,   configure a change in operational parameters or set-points,   perform a corrective action for an equipment or system.       

     The user, who is normally logged in to a data network and/or control system in the industrial installation, can share the information on his/her computer or workstation with another user in the following way: 
     a) A user opens a browser window and connects to a web server, starting a new session on the server, 
     b) the user browses for and finds information which is provided by the server: the server logs the client session; 
     c) information is transmitted to the client application of the user, formatted to the client display by means of one or more indicators, 
     d) all data that is sent to client of the user is logged on the server. The data logging is done through storing information about each session in a database. This information may comprise the time of access, pages visited, specific values of dynamic data given and the type of client (ie type of internet browser), and may comprise an indicator for display specifications or limitations or technical format requirements of a user machine, and;
 
e) The user decides to share the data with a second user, and activates a button, screen icon, keyboard command or similar to initiate a request to share with another user,
 
f) The user indicates an identity for one or more second users, and may also indicate sharing privileges such as read, read/write;
 
g) the server side process receives the request to share and sends the data of the session to a client of the second user.
 
f) alternately or as well a server process may access the session database to retrieve the information given to a specific user client at that moment or at a specified previous time and send it to a new client.
 
     The screen sharing principle relies on two or more clients (two or more computer program client processes running on a machine of each user) being enabled to connect to the same web server in a structured fashion. 
       FIG. 1  shows two user machines,  1 ,  2  with a connection to a third machine  3  running a process for a web server  6 . Machine  1  runs a first client, client A, and machine  2  runs a second client, client B. Each client may run a program that listens on a specific port for commands sent from the web server. Once a message from the web server is received, it is recognised and processed, it may for example be parsed, and the message then acted upon according to the command sent. 
     A user sets-up for a session by intialising. Information sharing may be initialised by a first client (Client A) requesting a share session with one or more other users, eg Client B. Client A then delegates privileges to client B by specifying privileges in, for example, an input box or field of a GUI (graphic user interface) display. These can for example be read/write or only read privileges, or more complicated privileges stating that client B cannot perform certain tasks (like turning off an engine, switching a power load from one busbar or line to another). A request is sent from the web server to client B notifying client B of a DS session. Client B can then choose whether or not to accept this. 
     When information is to be shared the technical requirements for the second user may be shown by an indicator in one or more of the documents, as described in d) above to signal that an HTML, IMode, WDL, WSL or other technical format or specification is required for the second user machine, and alternatively or as well, such an indicator may be retrieved from a database comprising information about the technical specification of each user machine. 
       FIG. 2  shows a flowchart for actions that may be carried out by a method according to an embodiment of the present invention. As shown in the flowchart the method may comprise actions such as: 
       20  first user activates first client A to request a share set-up; 
       21  web server  6  handles request and pushes a share page to client A; 
       22   a  share page loaded on client A; 
       22   b  first user enters IP address/name/other ID of client B; 
       22   c  first user enters privileges of client B, read, read/write, and/or more control or technical privileges 
       23  client A sends request as configured ( 22 ) for share screen; 
       24  web server opens new channel or stream to client B or socket for client B, communicates request for share screen; 
       25 Y client B user accepts Y the share screen, then 
       26  client B sends share screen accept to the web server; 
       27  web server sends share screen acceptance to client A; 
       28   b  server stores information about the current shared session; alternatively, 
       25 N at client B user declines N the share screen, then 
       29   a  client B send share decline to the web server; 
       29   b  web server sends share decline to client A. 
     Ordinarily a user, an operator, technician, engineer or other user inputs the identity, the IP address etc to identify one or more other users to share the current process with. However, this data may also or alternatively be supplied by a process running on a computer or processor. Information may also or instead be retrieved from the database described above containing details of the technical requirements of each user that may log-on to the system internally and/or externally. 
     For each request that comes in to the server or web server, a check is carried out to see whether is comes from a client presently involved in a sharing session. If so, all such clients participating in the session are sent the new information via a stream to their listening socket. The information may be detected by a routine, a program or an agent or watchdog that, for example, listens on a specific port for certain commands sent from the web server. 
       FIG. 3  shows a flowchart for a development of the present embodiment. As shown in the flowchart the method may comprise actions such as: 
       30  the web server receives a http request from client A; 
       32 Y the http request is from a process or machine in a current share screen session; 
       34  the web server formats documents of the current share session according to the privileges and technical specification known for client B; 
       35  web server opens new channel or stream to client B or client B socket, sends update command and metadata or structured text format for new page; 
     alternatively, 
       32 N the http request is not from a process or machine in a share screen session; 
       33  the request is handled normally and a response is pushed out or otherwise sent to client A. 
     The methods of the invention may be carried out remotely using a server application and a thin client A, B such as a web browser software, to provide a graphical user interface on a remote workstation or portable computer, notebook or other computing device. For example a technician may use a PDA (Personal Digital Assistant) or even a mobile phone enabled with applications to handle HTML, or similar or equivalent thin clients. Machines such as  1 ,  2  which may have different display features and technical limitations may be recognised or identified by use of a more specific format or technical specification than HTML, such as WAP or WDSL or IMode or similar or by formatting comprised in an HTML, XML, XSSL structured text or metadata format. Identification may also or as well be carried out as described above by retrieving an indicator for technical requirements from a database with details of the technical requirements for each known user machine that may be logged on to the system. 
       FIG. 4  shows schematically a screen display  40  of a user machine such as user machines  1 ,  2 . A button  42  or icon or other graphic symbol is displayed for the user to select in order to activate screen sharing, as indicated in step  20  of  FIG. 20 . This could instead be carried out by inputting text in a text field or command line if required. 
       FIG. 5  shows schematically the screen display with which the user can select which other users or experts he/she wishes to share information with. The figure shows a graphic object  43  that prompts the user to identify which second user or other second users are to be specified, and an input field  44  where an IP address or other means to identify a second user may be input. This input field may point to a database of known users and their technical requirements from which address and/or other user information may be retrieved. 
       FIG. 6  shows an exemplary display with which one or more privileges may be set for the user or users that the first user will share with. The figure shows a graphic object  46  that prompts the user to identify which access privileges the second user or and other second users are to be given. Each user is identified  47  in some way, and the privileges to be assigned  48  are arranged. These privileges may comprise rights to Read Only (R only) Read and/or write (R/W) and Other. Other privileges which may me an authority or technical authority indicated schematically by the column headed O (Other) may be registered in the sharing assigned to each other user, privileges that may be dependent on which functions are present in the industrial control or process control system or part thereof currently selected and/or displayed. For example rights to change a set point may be represented by a  1  (number  1 ), rights to start data logging by a number such as  3 , rights to start a diagnosis of data recorded for maintenance  2  and so on, to comprise other rights such as to switch off an alarm, to start a specified motor, to stop a motor, to switch a circuit breaker on or off, to change a voltage setting of a tap changer, and so on. Activation functions refers to functions in the web page or web client GUI display displayed eg by machines  1 ,  2  running a client A, or B may carried out by executable applications or applets which may be implemented as Java™ applets or ActiveX™ tools or similar. 
     Communication between server  3  running web server  6  may be established with other machines  1 ,  2  by wire and/or wirelessly. A machine with a client for interaction with a web server may for example be connected to a node of a wireless LAN, and/or may be another kind of wireless node, running any radio protocol suitable for an industrial milieu, such as any standard issued by the Bluetooth Special Interest Group (SIG), any variation of IEEE-802.11, WiFi, Ultra Wide Band (UWB), ZigBee or IEEE-802.15.4, IEEE-802.13 or equivalent, or similar. A standard compatible with WAPI (WLAN Authentication and Privacy Infrastructure, GB15629.11-2003 or later) may advantageously be used in situations where encryption of the wireless signal is necessary or advantageous. A radio technology working in the ISM band with significant interference suppression means such as by spread spectrum technology may be preferred. For example a protocol from ABB called Wireless interface for sensors and actuators (Wisa). Wireless communication may also or alternatively be carried out at least in part using Infra Red (IR) means and protocols such as IrDA, IrCOMM or similar. 
     By means of the data made available in an appropriate format to satisfy technical user machine requirements a technician, engineer, operator or other user may examine status or data for a process, configure a parameter, change a set points and/or remotely issue commands to an industrial control unit controlling an industrial equipment or process. The methods of the embodiments described above in respect of  FIGS. 1-6  and elsewhere in this specification may be carried out by a one or more computer applications comprising computer program elements or software code which, when loaded in a processor or computer, causes the computer or processor to carry out the method steps.  FIG. 7  shows another preferred embodiment of the invention. The user, who is normally logged in to a data network and/or control system in the industrial installation may require technical assistance for a process or device. This may be to supervise or adjust normal production/operations or may be for maintenance purposes or repair/troubleshooting purposes and so on. When the user browses technical, status or specification information associated with a given device or process, a button or icon or other activation function is displayed so that the user can request technical assistance.  FIG. 7  shows a display  40 , a plant with a process  70  with an equipment or function  71  of plant/process  70  selected, and a button  42 , or other activation function. The user may access technical information through the screen object underlying equipment or function  71 . By activating the Share Screen button  42 ′, the user causes a Screen share request screen or box eg  FIGS. 5 ,  6  to be displayed. The user can then input or select an identity of a Help Desk or another technical expert with whom to share the information currently displayed or to be displayed on his/her computer or workstation. Identities of one or more known technical experts or other engineers may also be displayed by activating a request for technical assistance button or function and thereafter entered in as an identity to share the technical information with. Thus with the minimum of steps and minimum of processing power at the local user computer, and with minimum use of bandwidth in the system, the user can re-distribute and thereby share his/her technical data with an expert. 
     The processor (or processors) comprise a central processing unit CPU performing the steps of the method according to one or more facets of the invention. This is performed with the aid of one or more said computer programs, such as a server application, a client watchdog, an address broker or part of, which are stored at least in part in memory and as such accessible by the one or more processors. The or each processor may be in a workstation, notebook, portable computing device, mobile phone, PDA (portable data assistant) or arranged connected to an industrial control unit or part thereof, or may as well run in a local or central control system in a local or distributed computerised control system. It is to be understood that any of said computer programs may be run on an industrial controller or on one or more general purpose industrial microprocessors or computers instead of one or more specially adapted computers or processors, FPGAs (field programmable gate arrays) or ASICs (application specific integrated circuits) or other devices such as simple programmable logic devices (SPLDs), complex programmable logic devices (CPLDs), field programmable system chips (FPSCs). 
     The computer program comprises computer program code elements or software code portions that make the computer perform the method using equations, algorithms, data, stored values and calculations previously described. A part of the program may be stored in a processor as above, but also in a ROM, RAM, PROM, EPROM or EEPROM chip or similar memory means. The program in part or in whole may also be stored on, or in, other suitable computer readable medium such as a magnetic disk, CD-ROM or DVD disk, hard disk, magneto-optical memory storage means, in volatile memory, in flash memory, as firmware, stored on a data server or on one or more arrays of data servers. Other known and suitable media, including removable memory media such as Sony Memory Stick™ and other removable flash memories, hard drives etc. may also be used. 
     The computer programs described may also be arranged in part as a distributed application capable of running on several different computers or computer systems at more or less the same time. Programs or procedures as well as data such as requests, acceptances, declined offers, or other share screen related information may be made available for retrieval, delivery or, in the case of programs, execution over the Internet. Data may be accessed by means of any of: OPC, OPC servers, an Object Request Broker such as COM, DCOM or CORBA, a web service. 
     Methods of the invention may also be practised, for example during an equipment installation or maintenance procedure, or during a configuration phase, and during normal production or process operations, locally or remotely by means of a Graphical User Interface (GUI), a graphical or textual or mixed display. Displays such as that exemplified by display  40  of  FIGS. 4-7  may be provided by an operator workstation; portable computing device; mobile phone suitably equipped to execute a client application and display an HTML or WAP or WDML or a similar page adapted to the technical requirements of the mobile phone/portable device; PDA and generally running on a user&#39;s logged-in computer. The user&#39;s logged in computer may be connected direct to an industrial control system or process control system or via a data network. The different users sharing the same process provided by the web server may be in different local, regional or national locations. 
     It should be noted that while the above describes exemplifying embodiments of the invention, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention as defined in the appended claims.