SCCT User Manual
Contents
1. 17 REGUCS ste mu E 21 R receiving PIM issih eios oed iced emat eia nest 31 Requests SERAING 21 5 sending AVID eee tet tetas Aesth ahi luce olay 31 start data transmission 19 stop data transmission 19 Subscriber Creatine RE 19 Wn Isu P a em 18 Pabsa tubo 18 SUDSCHIDER ClASS 18 timeout expired 27 U Us er R gU8SUu uu ctore es 24 X Lee ERR NEN RR E 31 dq c 31 SEM INS uuu dies eiut dtutiuttodas ins 31 Smartphone amp Cross platform Communication Toolkit User Manual2. Sending Requests Subscribers can send textual requests to the Publisher with sendRequest vi In this context user means your application and a request is a string message that Publisher receives and passes directly to its main application The following figure illustrates the path of user requests Client application Server application Requests are sent immediately to publisher and server processes them in the same order they are received If string is empty message is not posted You can specify an additional numeric code if your application uses numeric codes to identify request sets USER Figure 9 sendRequest vi example Receiving Messages Subscribers can receive textual messages from the Publisher with Read message vi a message is a cluster composed by a timestamp a string and a numeric code The following figure illustrates the path of alerts Client application Server application Messages are received and enqueued in a dedicated FIFO Your application have to process incoming messages and take care of FIFO size You can use Read Message vi to extract from the message FIFO the oldest received message 21 assa cade message Figure 10 Reading a message from Publisher activeSubscriberAddresses property node returns a 2D string array every row contains IP address port and description of an active subscriber Rows are ordered by connection start time so first row regards the oldest active conne
3. Managing User Requests User request i e message from subscriber is inserted into a FIFO by Publisher so your application can process all requests in the order they are received from Publisher The following figure illustrates the right way to manage the requests timestamp message sender Address Figure 14 Managing received request example First you have to check that found indicator is TRUE if found is FALSE no request is available Every request has its time field address port field that identifies the subscriber that sent the request and an optional data field Notifying an error When a LabVIEW error arises and must be notified to one or more subscribers use notifyError vi which composes a message with error code and error description from LabVIEW error cluster The following example shows how to use it Please note that you can specify a ipAddress port reference to send error only to a specific listener When error cluster contains no error no message is sent Analog DEL 1 Chan 15amp Figure 15 Notifying LabVIEW error to all subscribers with notifyError vi TOOLS for SMART MINDS 24 Smartphone amp Cross platform Communication Toolkit User Manual Advanced Options Controlling active connections Publisher Vis handle all incoming connections and close inactive connections so you just focus on your main application and forget all issues related to data transmission In some cases you want to kn
4. Package contains LabVIEW Vis as well as documents in PDF format accessible from LabVIEW Help TOOLS for SMART MINDS SCCT User Guide and libraries to create applications with Java Android and in c SCCT cross platform libs Visit http www toolsforsmartminds com to get more details TOOLS for SMART MINDS 10 Smartphone amp Cross platform Communication Toolkit User Manual Supported platforms SCCT is composed by two main components e publisher library e subscriber library publisher library this library let you create a full featured publisher which authenticates incoming subscribers check connection status sends data to all active publishers and passes their request to your application This library is available as a set of Vis for LabVIEW 2010 or later To get more details or download an evaluation copy of this library please visit http www toolsforsmartminds com products SCCT php Subscriber library This library let you create a subscriber which handles all communication details with a publisher so you don t have to It receives data packages and present them to your application according to their data types This library is available for the following platforms and languages System Development Language To get more details or download your free copy of SCCT subscriber library please visit http www toolsforsmartminds com products SCCT php This lib
5. Use property nodes to get information about active subscribers 25 Publishing digital lines on change only In many cases digital lines don t change very quickly so you can publish them only when they change in this way you can reduce the consumed band on your communication channel To change the way publisher works with your digital lines use the Digital publishOnlyOnChange property node If you want to publish digital lines also if they aren t changed set FALSE value to this property node If you want to publish digital lines only when their value is different from the previous one you published set this property value to TRUE By default a Publisher works with Digital publishOnlyOnChange equal to FALSE pu Nd NINE A LR ICIS e Publisherlvdass 5 Puiblisher lvclass 2557 Digital publishOnlyOnChange 77 Digital publishOnkyOnChange Figure 19 Changing the way digital data are updated to all subscribers with Digital publishOnlyOnchange property node If your application doesn t need to handle user request you can disable userRequest FIFO to avoid waste of memory To disable or enable FIFO use enableEventLogging property node as shown in the next figure lt r r r 5 Publisher lvclass 2 penu k enableEventLogging enableEventLogging enableLogging n E isEventLoggingEnabled Figure 20 Enabling the request FIFO with enableEventLogging property node Instead of prop
6. a connection before re open 6005 Connection refused from Publisher refused the connection because API Key Publisher wrong API Key is not correct 6006 Publisher not found No answer from specified address possible reasons publisher is down or not reachable 6007 Publisher Address cannot be Publisher Address cannot be an empty string empty 33 Index A active connection AGOVOSSES I u un Analog data PuDIIIYSu su aa massa auyasuwauassasa sha 15 API Key epe authentication successful available C Communication Custom data ENUT LTES dien custom XML 888 uum uuu nu te eb ett D data transmission Digital data PUDIISDI ixi u u a E Error Notifyinig EOF error codes Publisher uu ttem rade Sas SUbSCTIIDOe G asa Event authentication successful connection closed by client ood s su uu timeout expired M Messages uy TOOLS for SMART MINDS 34 P Publisher erui Er 15 MM idgrero RH 14 elgole igd cpe u y yuy t 14 PuBlisher G 899 uuu uuu aus yuna s sus 14 Publishing Analog Data 15 CUSTOM Dat u u u kuu un u awan 30 31 Digital Data
7. m Figure 7 Simple subscriber example that reads digital data only Publisher automatically sends a communication cluster that describes the remote system Use this cluster to properly format your graph and chart setting x and y scales as shown in the following figure localhost Seo ciu cmm D ri 53 mig LL gt um ar EE Figure 8 Simple Subscriber that reads configuration cluster before reading analog data Notice openCommunication vi create a background task which handles the data transfer to and from the publisher This task is also responsible of checking if connection is lost in case publisher is not sending any information This task periodically checks if your top level VI is running and stops automatically when your top level VI stops Optionally you can add an application s description to the openConnection vi Server side application will use the description to identify your application This is useful when the server has to properly identify subscribers name but they change IP address or port at every new connection typically when DHCP is used to assign IP addresses If description is not specified server will identify the connection with the string TOOLS for SMART MINDS 20 Smartphone amp Cross platform Communication Toolkit User Manual XXX XXX XXX XXX yyyy XXX XXX XXX XXX is subscriber application IP address and is local port used to connect to server
8. of requests Creating a Publisher To create a publisher in your LabVIEW application use the palette SCCT Publisher The following examples show how to create a publisher in few click To create a publisher in your application you must choose two parameters that have to shared with subscribers e Publisher port is the TCP port that Publisher uses to manage all TCP connections e API Key is the connection password that subscribers must communicate to publisher to be authenticated Take care to use one of the available port of your machine Some ports are reserved for other common applications like port 21 to FTP 80 to HI TP and so on Moreover you have to check that the chosen port is open on your company firewall Publishing analog data i T Figure 3 Simple Publisher example with analog data In the example above a Publisher is created with startPublisher vi that immediately creates all necessary data structures and tasks and takes care of all incoming connections Please note that configuration cluster must be filled according to the analog signals you want to transmit channelConfiguration must describe each channel of your data acquisition In the while loop your acquired data are published directly to the active subscribers If no subscribers are connected data are discarded When the loop terminates stopPublisher vi closes all active tasks and flushes FIFO with user requests 15 Notice startPublisher vi create
9. some background tasks which handle the data transfer to and from active subscribers These tasks are also responsible of checking if connections are lost in case your application is not publishing any information All these tasks periodically check if your top level VI is running and stop automatically when your top level VI stops Defining a system configuration Publisher requires a system configuration cluster with at least one analog channel description or one digital line description If you connect an empty configuration cluster startPublisher vi rises up an error and doesn t start The reason of this is behavior because in past SCCT was used to publish data from acquisition boards Now many new features are available and SCCT can be used to transmit a wide range of different data types not related to any data acquisition but configuration constrain remains to keep compatibility with legacy code TOOLS for SMART MINDS 16 Smartphone amp Cross platform Communication Toolkit User Manual Publishing digital data In this example a Publisher is created with startPublisher vi that immediately create all necessary data structures and tasks and takes care of all incoming connections Please note that configuration cluster must be filled according to the digital lines you want to transmit digitalLines Configuration must describes each line of your data acquisition In the while loop your acquired data are published directly to the a
10. ALOG DATA ONLY meses essen 19 FIGURE 6 TRANSFERSTATUS VI DETERMINES THE FLOW OF PACKETS BETWEEN PUBLISHER AND SUBSCRIBFER 19 FIGURE 7 SIMPLE SUBSCRIBER EXAMPLE THAT READS DIGITAL DATA ONLY a r 20 FIGURE 8 SIMPLE SUBSCRIBER THAT READS CONFIGURATION CLUSTER BEFORE READING ANALOG DATA 20 FIGURED SENDREQUEST VI EXAMPLE u l uu a voient ees u tru E e Ous bai 21 FIGURE 10 READING A MESSAGE FROM PUBLISHER 00cosescsssscvnsscscssccssvecsnsccvsconvssevsndevecessscesuscssscseossecvesscnses 22 FIGURE 11 USING PROPERTIES NODES TO CHECK CONNECTION STATUS 22 FIGURE 12 USING AVAILABLE REQUEST PROPERTY NODE TO CHECK IS SUBSCRIBER S REQUESTS ARE 23 FIGURE 13 SENDING MESSAGE TO A SPECIFIC SUBSCRIBER WITH SENDMESSAGE VI 23 FIGURE 14 MANAGING RECEIVED REQUEST EXAMPLE 0 0 cscnscosssovsnscssescossuevsnvcovavcvedsoscvensobsactessesssecsvaccsvensevenseouss 24 FIGURE 15 NOTIFYING LABVIEW ERROR TO ALL SUBSCRIBERS WITH NOTIFYERROR VI 24 FIGURE 16 USE READ ACTIVESUBSCRIBERSCOUNT VI TO CHECK THE COUNT OF ACTIVE CONNECTIONS 25 FIGURE 17 USE READ ACTIVESUBSCRIBERSADDRESSES TO GET INFO ABOUT ACTIVE S
11. CT Vis your applications is supported on an wide range of platforms Android iPhone etc SCCT is safe because every device must authenticate to your application and you can control who is connected in any time Using SCCT you deliver open solution to your customers because they can use their favorite mobile platform to connect to your data And if customers change mobile device family you don t need to modify your code Delivering high quality maintenance service to your customer Including SCCT into your existing applications let you offer fast support to your customers You and your customers can monitor deployed applications everywhere with a tablet phone desktop integrating SCCT capabilities into existing applications makes easy debug and signal analysis of deployed systems around the world Installing the Smartphone amp Cross platform Communication Toolkit Smartphone amp Cross platform Communication Toolkit is shipped as a VI Package Manager You can download it from www toolsforsmartminds com products SCCT php Before installing Smartphone amp Cross platform Communication Toolkit you must install a copy of VI Package Manager on your machine You can get a free copy of VIPM at this address http www jki net viom download To install Smartphone amp Cross platform Communication Toolkit double click open the vip file smartphone amp crossplatform communication toolkit x x x xx vip and follow the installation wizard
12. ING AND MANAGING ALERTS AND USER REQUESTS OVERVIEW READING AVAILABLE REQUESTS SENDING MESSAGE TO A SPECIFIC SUBSCRIBER MANAGING USER REQUESTS NOTIFYING AN ERROR ADVANCED OPTIONS CONTROLLING ACTIVE CONNECTIONS READING ACTIVE CONNECTION COUNT READING ACTIVE CONNECTION ADDRESSES PUBLISHING DIGITAL LINES ON CHANGE ONLY MANAGING EVENTS CHANGING API KEY AT RUN TIME CHANGING MAX DT PUBLISHING AND RECEIVING CUSTOM DATA SUPPORTED ONLY BY LABVIEW APPLICATIONS PUBLISHING AND RECEIVING CUSTOM XML DATA APPENDIX A ERROR TABLE TOOLS for SMART MINDS 4 Smartphone amp Cross platform Communication Toolkit User Manual CO O O O 09 N N O P P gt PP oO 12 12 14 14 15 15 16 17 18 19 19 21 21 22 22 23 23 23 23 24 24 25 25 25 25 26 27 28 29 30 31 33 PUBLISHER ERROR CODES SUBSCRIBER ERROR CODES INDEX 33 33 34 Figure index FIGURE 1 HOW DATA PACKAGES ARE ORGANIZED AT SUBSCRIBER SIDE r 12 FIGURE 2 AN APPLICATION CAN PROCESS INCOMING PACKAGES ACCORDING TO THEIR DATA TYPES 13 FIGURE SIMPLE PUBLISHER EXAMPLE WITH ANALOG 15 FIGURE 4 SIMPLE PUBLISHER EXAMPLE WITH DIGITAL DATA een ese ese se sse esse esse esse essen 17 FIGURE 5 SIMPLE SUBSCRIBER EXAMPLE THAT READS AN
13. LA AAI AAA ALANA SA AAA AAA AAA AGRAR GASES AAA apama saca aaa Ny i de detto ata type 2 gt TE sss description 2 data z cu EM Figure 27 publisher application and subscriber application use code field to identify the proper data type Both apps have to know the data type associated to the codes TOOLS for SMART MINDS 30 Smartphone amp Cross platform Communication Toolkit User Manual Publishing and receiving custom XML data In addition to messages and requests both sides of communication channel can exchange XML documents XML packets have been added to SCCT to allow server and client applications exchanging complex custom data with a single function Remember that XML documents are not check by SCCT Vis You must verify XML document s correctness before transmission to avoid unpredictable behaviors by receiving applications The following figures illustrate the available set of Vis in Publisher and Subscriber s libraries Notice that on Publisher side XML transmission is done with the Polymorfic VI PublishData vi timestamp value AMLDocument timestamp AMLDacument Figure 31 With Subscriber use Read customXMLData vi to process XML packets Publisher and Subscriber manage XML document transfer in the same way 31 OIL SSS lt lt lt lt 5 mt Subscriber yclass SSS availableCustom MLDatar
14. Smart phone amp Cross platform Communication Toolkit User Manual LabVIEW Release 1 0 1 July 2011 Edition Revision 1 0 1 70 Worldwide technical support and product information www toolsforsmartminds com TOOLS for SMART MINDS Corporate headquarter Via Padania 16 Castel Mella 25030 Brescia Italy Copyright 2010 Tools for Smart Minds All rights reserved TOOLS for SMART MINDS 2 Smartphone amp Cross platform Communication Toolkit User Manual Contents FIGURE INDEX ABOUT THIS MANUAL CONVENTIONS INTRODUCTION OVERVIEW TOP REASONS TO USE SMARTPHONE amp CROSS PLATFORM COMMUNICATION TOOLKIT SCCT SCCT APPLICATION EXAMPLES COMMUNICATING DATA ACROSS A NETWORK ON A COMPLEX ASSEMBLY LINE PUBLISHING REAL TIME DATA TO MOBILE DEVICES DELIVERING HIGH QUALITY MAINTENANCE SERVICE TO YOUR CUSTOMER INSTALLING THE SMARTPHONE amp CROSS PLATFORM COMMUNICATION TOOLKIT SUPPORTED PLATFORMS PUBLISHER LIBRARY SUBSCRIBER LIBRARY GETTING STARTED WITH THE SMARTPHONE amp CROSS PLATFORM COMMUNICATION TOOLKIT COMMUNICATION CONCEPTS USING THE SMARTPHONE amp CROSS PLATFORM COMMUNICATION TOOLKIT PUBLISHER CLASS CREATING A PUBLISHER PUBLISHING ANALOG DATA DEFINING A SYSTEM CONFIGURATION PUBLISHING DIGITAL DATA SUBSCRIBER CLASS CREATING A SUBSCRIBER STARTING AND STOPPING DATA TRANSMISSION SENDING REQUESTS RECEIVING MESSAGES HOW TO CHECK THE STATE OF YOUR CONNECTION CLOSING COMMUNICATION CREAT
15. TION OR SOME ERRORS OCCUR DURING DATA TRANSFER OR TIMEOUT EXPIRES 28 FIGURE 24 CHANGING API KEY TO AN ACTIVE PUBLISHER WITH WRITE API KEY VI 28 FIGURE 25 CHANGING API KEY TO AN ACTIVE PUBLISHER USING API KEY PROPERTY NODE 29 FIGURE 26 CHANGING MAXDT TO CHECK SUBSCRIBER S SYSTEM TIME ccccsecececccecsececececceuuceeseseuuseusceuueeuseeuseeueesens 29 FIGURE 27 PUBLISHER APPLICATION AND SUBSCRIBER APPLICATION USE CODE FIELD TO IDENTIFY THE PROPER DATA TYPE BOTH APPS HAVE TO KNOW THE DATA TYPE ASSOCIATED TO THE CODES scceceesesseseeseesenseuseecssuseeceeseeseseuseueass 30 FIGURE 28 WITH PUBLISHER USE PUBLISHDATA VI METHOD TO SEND XML DOCUMENTS 31 FIGURE 29 WITH SUBSCRIBER USE SENDCUSTOMXMLDATA VI TO SEND XML DOCUMENTS TO PUBLISHER 31 FIGURE WITH PUBLISHER USE READ CUSTOMXMLDATA VI TO PROCESS XML PACKETS 31 FIGURE 31 WITH SUBSCRIBER USE READ CUSTOMXM LDATA VI TO PROCESS XML PACKETS 31 FIGURE 32 WITH PUBLISHER AND SUBSCRIBER YOU HAVE DIFFERENT METHODS AND PROPERTY NODES TO GET THE COUNT OF AVAILABLE XML UNPROCESSED DOCUMENTS cce acer aov aae vemm repo PE IS TUER E ABER Y 32 TOOLS for SMART MINDS 6 Smartphone amp Cross plattorm Communication
16. Toolkit User Manual About this Manual The Smartphone amp Cross platform Communication Toolkit User Manual describes the virtual instruments Vis used to communicate and pass data between LabVIEW and either a local or remote application You should be familiar with the operation of LabVIEW your computer and your computer operating system Conventions The following conventions appear in this manual 4 The symbol leads you through nested menu items and dialog box options to a final action The sequence Tools Options directs you to pull down the Tools menu select Options item Bold Bold text denotes items that you must select or click on the software such as menu items and dialog box options Bold text also denotes parameter names italic Italic text denotes variables emphasis a cross reference or an introduction to a key concept This font also denotes text that is a placeholder for a word or value that you must supply monospace Text in this font denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax examples This font is also used for the proper names of disk drives paths directories programs subprograms subroutines device names functions operations variables filenames and extensions and code excerpts monospace italic Italic text in this font denotes text that is a placeholder for a word or value that you must supply Introduction This chap
17. UBSCRIBERS 25 FIGURE 18 USE PROPERTY NODES TO GET INFORMATION ABOUT ACTIVE SUBSCRIBERS 25 FIGURE 19 CHANGING THE WAY DIGITAL DATA ARE UPDATED TO ALL SUBSCRIBERS WITH DIGITAL PUBLISHONLYONCHANGE PROPERTY NODE icis viz igen Oe htm oe duse ote ine nga aw oat MODUS rossa oe ncaa visa helps pocas een 26 FIGURE 20 ENABLING THE REQUEST FIFO WITH ENABLEEVENTLOGGING PROPERTY NODE INSTEAD OF PROPERTY NODE YOU CAN SET THE FLAG ENABLELOGGING WITH ENABLELOGGING VI AND GET ITS VALUE WITH ISEVENTLOGGINGENABLED VI RESPECTIVELY ssccscscescsceseecussuccssuccsseccseuceseeteceseecnseesuseesnseesuscesestecseesaseesa 26 FIGURE 21 ENABLING THE REQUEST FIFO WITH ENABLEEVENTLOGGING PROPERTY NODE INSTEAD OF PROPERTY NODE YOU CAN SET THE FLAG ENABLELOGGING WITH ENABLELOGGING VI AND GET ITS VALUE WITH ISEVENTLOGGINGENABLED VI RESPECTIVELY 0 ccossssvsccsvsscsasssccctscsvscoussevscstnevsacsasscnsvessssossucovsvenseunscessestecs 2 FIGURE 22 THIS EXAMPLE SHOWS HOW TO MANAGE AUTHENTICATION SUCCESSFUL EVENT FOR INSTANCE NOTICE THAT WELCOME MESSAGE IS ADDRESSED TO NEW CONNECTED SUBSCRIBER AND OTHER ACTIVE SUBSCRIBERS ARE NOT AFFECTED BY THIS MESSAGE e uuu ata as u Sah Gaal Ente Rmo Gann M MI ais eR RI DU 28 FIGURE 23 THIS EXAMPLE SHOWS HOW TO MANAGE THE CASE A CONNECTION IS NO MORE ACTIVE IT CAN HAPPEN WHEN CLIENT CLOSES THE CONNEC
18. ackages are published according to server logic and subscriber side task organizes the nine received packages into different FIFO structures PUBLISHER SIDE SUBSCRIBER SIDE Text package Message Analog data package 7 af Last sent package newest First sent package oldest 7 sje Gs 87876700 gt dn Other package type FIFOs Figure 1 How data packages are organized at subscriber side TOOLS for SMART MINDS 12 Smartphone amp Cross platform Communication Toolkit User Manual In this architecture packages can be processed very easily with dedicated Vis In many real life applications the exact order in which data packages are generated is not very important and with LabVIEW multithread capability you can dedicate specific task to every package type and deliver robust software solution as shown below ANALOG COGI ii i i i i i i i i E Ri USER 1 abc USTOM DAT Figure 2 An application can process incoming packages accoraing to their data types Because of the wide range of devices the Smartphone amp Cross platform Communication Toolkit works with some portability issues remain Consider the following issues when choosing your way to publish data Some smart phones and tables uses CPU with low computing power so are not able to receive and process large streams of data Smartphone amp Cross platform Communication Toolkit u
19. apter we discover where SCCT helps developers to succeed to deliver high valued solutions Communicating data across a network on a complex assembly line Creating an application which broadcasts part numbers and barcodes coming from databases or bar code readers to all computers on a assembly line as schematized below On modern assembly lines many computers control single processing stations and they need to exchange data among them to know part numbers print codes and certificates store test results on different databases SCCT provides many functionality to exchange data with applications developed with heterogeneous programming languages besides when your customer asks you to show some data on a mobile device SCCT is capable to communicate with a large variety of smart phones and tables and you don t have to change a single line of code of your software SCCT cares of all connected devices and communicate your data to all of them at the same time receives user s requests and organize them in a time ordered FIFO so that you can process them easily Um p I V mp pm EC Bar code L A 4 al F tl Publishing real time data to mobile devices When you have to publish acquired data in real time SCCT is the best choice because with few SC
20. availableCustomsMLOata Figure 32 With Publisher and Subscriber you have different methods and property nodes to get the count of available XML unprocessed documents TOOLS for SMART MINDS 32 Smartphone amp Cross platform Communication Toolkit User Manual Appendix A Error table In the following tables are indicated the error codes generated by VIs Publisher error codes A method or property has been called before creating the Publisher port When you start the publisher you have to provide a valid TCP port message 5003 Invalid API Key API Key cannot be an empty string 5004 Invalid p Pe MEIN cluster must contain at least 1 Pe MEIN channel or 1 diaital line analog data Analog data must be a 2D array with exactly the number of rows equal to the number of analog channels as defined in configuration cluster A Digital data must be a 1D array with size equal to to the number of digital lines as defined in TUPTUPTISTT T uration cluster 5008 library is corrupted UOCE OR E error during creation of communication tasks Subscriber error codes establishing the connection or it has been closed When you start the publisher you have to provide a valid TCP port 6002 invalid timeout Timeout must be a value greater than zero 6003 Invalid API Key API Key cannot be an empty string 6004 Connection cannot be created openConnection vi cannot be used on an active twice connection You have to close
21. azine When they don t want to receive it anymore simply cancel their subscription Your application can implement more than one Publisher each of them works on different port of your machine An application can contain publishers and subscribers together working with different remote machines at the same time Either objects work in background of your application with specific tasks that are created and destroyed automatically This library has been created to LabVIEW developers and includes some advanced features supported only by LabVIEW apps Please be careful when design your communication solutions so that your data can be properly treated by all subscriber So when your system is designed to work with LabVIEW programs only customData packages greatly simply data transfer among processes but cannot be processed by subscribers created for example with SCCT for Java Publisher Class Publisher is a Class with methods and properties detailed in the following tables Publisher Class properties Property name Read write availableRequests Read only enableEventLogging Read Write Port Read API Ke Read Write activeSubscribersCount Read only activeSubscribersAddresses Gets the IP address and port of each active connection Read only Digital publishOnlyOnChange Defines how digital lines are published if true digital lines are transmitted Read Write only if their value is changed otherwise they are transmitted every time regardl
22. ction and last row regards the most recent connection How to check the state of your connection You can monitor connection state with connected property node which returns TRUE if your connection is still alive A connection is alive also if Publisher is not sending data to your subscriber Publisher and subscriber exchange acknowledge packets to verify if connection is still active so you don t have to Figure 11 Using properties nodes to check connection status Closing communication When connection is no more necessary use closeCommunication vi to close the open connection This VI destroys all unprocessed data and closes background tasks After this Vl subscriber object cannot be used and a new instance must be created with openCommunication vi TOOLS for SMART MINDS 22 Smartphone amp Cross platform Communication Toolkit User Manual Creating and managing alerts and user requests Overview When an active communication is established between Publisher and subscriber they can exchange some messages with a specific format messages from your application to subscriber s are called Alerts Every alert is composed by a numeric code and a message string Messages from subscribers to your application are called user requests Every user request contains a numeric code a timestamp a connection identifier an event code and an optional data string Publisher uses a FIFO to enqueue all incoming user requests in the order they ar
23. ctive subscribers If no subscribers are connected data are discarded When the loop terminates stopPublisher vi closes all active tasks and flushes FIFO with user requests Configuration 5051 Www s ma eg eg gs k k k DAQ Assistant k k k m i Figure 4 Simple publisher example with digital data Please note in the above figure that when you start a publisher you create a publisher object with a small set of parameters The new object will manage by itself most of communication details If you want to modify the way communications are handled use LabVIEW property nodes to set desired values to publisher options The time that occurs between the execution of publishData vi and the effective transmission of data package to all active subscribers is usually few milliseconds and depend mostly on data size not on the active connection number Subscriber Class Subscriber is a Class with methods and properties detailed in the following tables Subscriber Class properties process application has to process availableConfiguration Gets the number of configuration clusters received from publisher that Read only application has to process Remember that when you establish a connection ou receive immediately a configuration cluster has to process Returns TRUE if connection is active FALSE if connection is lost connectionStatus Gets a numeric code related to connection stat
24. d digital data are managed in situation YOUR APPLICATION PUBLISHER SIDE I I I I When I i transferStatus FALSE publisher doesn t send fresh data to subscriber I I I I I I I I I I I I if fy 7 zT 7 m connection Connection start here transferStatus FALSE transferStatus TRUE Figure 6 transferStatus vi determines the flow of packets between publisher and subscriber Starting and stopping data transmission Publisher doesn t start data transmission automatically After connection your subscriber must tell to the Publisher to start sending data If your subscriber doesn t need fresh data use transferStatus vi with a FALSE constant to tell to publisher to 19 stop sending data To re start data transmission use transferStatus vi with TRUE constant To get analog data use Read analogData vi that returns a packet of data Background tasks takes care of all received packets and enqueues them in a FIFO so you can process all packets without data loss To know the number of available packet use the property node that returns the data packets count The following figure illustrate the case of reading digital lines only Notice that at the end of the while loop you always have to close communication with publisher When communication is closed if you want to open again the communication use openCommunication vi localh nen ri a5 5082 08 eee
25. d to it are deleted from disk Notice that the case structure uses both conn closed by client and timeout expired events TI cann clased client timeout exnired k lt ua ua um um event 5 k sender address F delete temporay Files used by my application to manage this connection now they are not needed anymore Figure 23 This example shows how to manage the case a connection is no more active It can happen when client closes the connection or some errors occur during data transfer or timeout expires Changing API Key at run time Publishers are created with an API Key they use to authenticate every incoming connection You can modify the API Key at run time so that new subscribers have to use the new API Key to be accepted Existing connections are not affected by API Key changes To update the API Key use Write API Key vi as shown in the following figure Figure 24 Changing API Key to an active Publisher with Write API Key vi TOOLS for SMART MINDS 28 Smartphone amp Cross platform Communication Toolkit User Manual Alternatively you can use API Key property node as shown below aisi daa R t Publisher class 7 u PI Key Figure 25 Changing API Key to an active Publisher using API Key property node Changing max DT When subscribers try to connect the request includes their system time If subscriber s system time differs from publishers system t
26. e received Your application can identify which subscriber is sending the request by its ipAddress port identifier Reading available Requests Subscribers send their request to your application and Publisher keeps them in a FIFO together with some messages it sends to inform your application about the connection status and the communication between publisher and subscribers Use availableRequests property node to retrieve the number of received request that your application has to process When a request is processed with getRequest vi availableRequests is decremented by 1 gt Publisher availableRequests P availableRequests Figure 12 Using available request property node to check is subscriber s requests are present Sending message to a specific subscriber Your application can communicate with active subscribers with custom messages To send a message use sendMessage vi as shown in the following figure port Figure 13 Sending message to a specific subscriber with sendMessage Use message string to add additional information to your message To send a message to every active subscriber ipAddress port must be empty string instead if 23 you want to send a message to a specific subscriber connect ipAddress port to the specific address and port of its connection Message string cannot be empty If try to send an empty string message error is generated with error code 5002
27. erty node you can set the flag enableLogging with enableLogging vi and get its value with isEventLoggingEnabled vi respectively By default every Publisher starts with FIFO enabled so remember to consume elements in this FIFO with getEvent vi or disable the FIFO with enableEventLogging property node Many properties can be set either by specific Vis or by properties nodes We encourage you to use properties node whenever it is possible TOOLS for SMART MINDS 26 Smartphone amp Cross platform Communication Toolkit User Manual Managing events Publisher provides a FIFO used to keep track of communication events This FIFO is enabled by default and can be enabled disabled with eventLogging property node see above Event data cluster contains the following information e timestamp is the local time when event is occurred e Event describes the type of event The available event types are o authentication successful occurs when a new connection is properly established Is a remote device tries to connect but its connection parameters are not correct and connection is refused this event is not generated o conn closed by client occurs when a client terminates connection o timeout expired occurs when a connection is lost abnormally for example when communication channel fails In this situation your application cannot be sure that all transmitted packets have been received by client associated to aborted connection se
28. ess of their value maxDT Sets gets the maximum allowed time difference between publisher time clock Read Write and subscribers time click Publisher Class methods method name description PublishData Publishes analog and or digital lines startPublisher Implements a publisher object stopPublisher Destroy a Publisher object updateConfiguration Transmit a new system configuration to all active connections getRequest Get the first unprocessed request from one of the active connections getEvent Get the first unprocessed event sendMessage Transmit a message to a specific connection or to all active connections notifyError Transmit a message to a specific connection or to all active connections with a TOOLS for SMART MINDS 14 Smartphone amp Cross platform Communication Toolkit User Manual Read availableRequestCount Read activeSubscriberCount Read activeSubscriberAddresses Read Port Read API Key Write API Key Read publishDigitalDataOnlyOnChange Returns the property that defines how digital lines are published if true digital lines are transmitted only if their value is changed otherwise they are transmitted every time regardless of their value Write publishDigitalDataOnlyOnChange Sets the property that defines how digital lines are published if true digital lines are transmitted only if their value is changed otherwise they are transmitted every time regardless of their value enableEventLoggino Enables the management
29. ime more than maxDt and maxDt is greater than zero connection is refused By default maxDt value is zero so subscriber s system time is not checked To enable time control use maxDt property node to set the absolute value of maximum distance in seconds between local and remote system s time r 5 Publisher lvclass 7 Figure 26 Changing maxDt to check subscribers system time 29 Publishing and receiving custom data supported only by LabVIEW applications If both side applications use SCCT for LabVIEW then some advanced features are available These features rely on LabVIEW variant data type and their data package are not supported on other programming languages if more than one custom data type is used custom data types must be associated to a numeric code or string description so that subscribers can properly identify what data has been sent from publisher In the following example publisher side on the left encode two different data types and send them with publishData vi Notice they are associated to code 1 and 2 Subscriber application on the right receive the packages with Read customData vi and uses code field to properly process data type 1 and data type 2 09 _ timeStamp P code m I value jp description m customData gt pH e SS SIUS A AAA AAA ASA ALAS AIDA AA AA AAA AAA AAA ALA DA IAAI A
30. ing that indicates the connections status or the failure reason in case openConnection doesn t succeed to establish a valid connection To implement the subscriber in your application and receive data from a source you must know three parameters e Data source address that is usually the IP address of the machine where Publisher is running on e Data source port that is the TCP port of the Publisher API Key is the key necessary to be authenticated by publisher If a subscriber uses a wrong API Key connection is refused by publisher TOOLS for SMART MINDS 18 Smartphone amp Cross platform Communication Toolkit User Manual After I I Publisher sends the i most recent data it has I so that subscriber can I I I I I When your application succeeds to connect publisher sends immediately a configuration of remote system i e analog channel descriptions unit of measure and range of all signals digital line descriptions and system location GPS coordinates Creating a Subscriber In the following example you create a simple subcriber with openConnection vi that need three parameters Publisher address default value is localhost Publisher port default value in 8081 and API Key localhost CHH a 9082 eee abc stop Figure 5 Simple Subscriber Example that reads analog data only Publisher doesn t buffer data if transmission is stopped The following diagram illustrates how analog an
31. latforms and programming languages It s reliable many applications have been created with this toolkit around the world Speed up your development activity this toolkit allows the creation of distributed application and let you save a lot of your time SCCT has been created by LabVIEW developers for LabVIEW developers it includes some great features supported on LabVIEW platform only see Publishing CustomData in this manual so if you need to exchange data with other LabVIEW applications take TOOLS for SMART MINDS 8 Smartphone amp Cross platform Communication Toolkit User Manual advantage of the power of SCCT to deliver high quality code and reduce developing time Today applications need to retrieve information from database bar code readers OCR systems remote data acquisition or technical operators with mobile devices Often you have to create systems capable to exchange data with legacy applications created on different platforms Every time you have to design an ad hoc communication protocol code both server and client side routines debug them Every time With SCCT you have a new tool that let you save a lot of time lets you focus on your project s core and manage multiple communications at the time In the following examples you are going to see how SCCT can dramatically improve the quality of your software solutions SCCT application examples SCCT can be successfully applied in many real world situations In this ch
32. nderAddress is the address of new subscriber in the form IpAddress port use availableEventCount property node to check is new events have been generated When a new event is present you can extract it from its event Queue with getEvent vi method as shown in the following figures availableE yentCount j availableEyentCount um um um s s 0 UI ERI EI HI availableRequestCount Figure 21 Enabling the request FIFO with enableEventLogging property node Instead of property node you can set the flag enableLogging with enableLogging vi and get its value with isEventLoggingEnabled vi respectively Events are useful when your application keeps track of existing connections and must execute special tasks when a new connection is established or an existing one is closed Below you see a simple example a welcome message is sent only to new connected applications senderAddress is the address associated to the connection that generated the event 27 arat i True here y ou specifies receiver address same as sender address Figure 22 This example shows how to manage Authentication Successful event for instance Notice that welcome message is addressed to new connected subscriber and other active subscribers are not affected by this message In the following figure a different situation is managed when a connection is terminated some temporary files associate
33. ow the number of active connections and the address of subscribers Usually you can map all incoming connections using getRequest vi and filtering events such connection successful and connection closed and connection timeout which help you to map all active and closed connections Reading active connection count To know the count of active connections at a specific time use Read activeSubscribersCount vi that returns the number of active connections active anneckians Figure 16 Use Head activeSubscribersCount vi to check the count of active connections Reading active connection addresses To know the addresses of active subscribers use Read activeSubscribersAddresses vi that returns a string array every string is a subscribers address in the form ipAddress port the array is ordered by connection time so the first element of the array is related to the active subscribers that connected first Closed connections don t appear in the array active Subscribers Figure 17 Use Read activeSubscribersAdaresses to get info about active subscribers You can use activeSubscriberCount property node to get active connection count and activeSubscriberAddress property node to get active connection addresses as shown in the following figure is Publisher leclass ai LTE AA ERR active SubscribersCount F active Subscribers4ddress Harna active SubscribersCount active Subscribers4address Figure 18
34. rary is included in SCCT VIPM package and is not available separately from SCCT Publisher library This library is distributed as OCX component and can be used by any language that support ActiveX technology This library will be available from august 2011 this library works on x8 6 32bit and ARM ver 11 processor families This library will be available from Q4 2011 This library will be available from Q4 2011 11 Getting started with the Smartphone amp Cross platform Communication Toolkit Communication concepts Smartphone amp Cross platform Communication Toolkit is based on the publisher subscriber pattern also called Observer pattern In this pattern you have one application publisher that receives the data you want to publish and one to many applications subscribers which subscribe the service To subscribe the service and receive fresh data from the publisher they must use an API KEY to be authenticated The following figure represents the pattern Subscriber 1 Your application Subscriber 2 Subscriber N When an application wants to receive data first asks the publisher to be inscribed among the active subscribers Publisher will accept all incoming requests with the valid API KEY Publisher Received data are organised into separated FIFOs so that subscriber application can process data packages according to their types In the following figure its shown the case some different type p
35. ses a platform independent data format and subscribers require a some computing power to decode data streams into their specific binary format omartphone amp Cross platform Communication Toolkit handles communication with subscribers as a set of peer to peer connections and every data you publish is transmitted individually to each subscriber So you have to identify the right size of your data streams to avoid band saturation over your communication channel oome data types are not supported on all platforms Using the Smartphone amp Cross platform Communication Toolkit This Toolkit is composed of two main components Publisher that creates the server side of your communication system and the subscriber that implements the client side Publisher and Subscriber work together to pass data from one application which holds the data to many applications on different systems MS Windows OS family Linux Apple systems mobile devices etc Publisher uses a platform independent data format to transmit your data so that all subscribers can read them Doing so you add a little overhead to a simple transmission that uses binary data format but gain a great portability and opportunity to communicate with heterogeneous systems To better understand the way this communication works think of this example A publishing company receives requests from different subscribers who want to receive a magazine As long as they are subscribed they receive the mag
36. ter describes the installation procedure installed components and the main features of the Smartphone amp Cross platform Communication Toolkit Overview The Smartphone amp Cross platform Communication Toolkit is an add on package for communicating data trough applications The toolkit contains a set of high level functions for sending your application data and advanced functions for customized tasks The following list describes the main features of the Smartphone amp Cross platform Communication Toolkit e Works over any TCP IP connection Works over Local Area Networks as well as Internet connections Implements the publisher subscriber pattern also known as Observer pattern Authenticates subscribers through a API KEY Controls in background the state of every connection to identify loss of communication Publishes GPS coordinates to manage mobile systems Works with platform independent Data format and communicate with multiple platforms at the same time third party vendors have implemented toolkit to develop on Android platform Java NET and VB Unix and iOs Top reasons to use Smartphone amp cross platform Communication Toolkit SCCT Adopting this toolkit you have the following advantages Simplify communication dont care about communication details over a TCP communication channel SCCT does it for you Multiple platforms are supported exchange your data with a protocol supported on a wide range of p
37. us Subscriber Class methods description Creates a subscriber and open a connection with a running Publisher Destroys a subscriber and close connection if active Reads next available alert received from Publisher data transmission you must use transferStatus vi Reads next available digital data packet received from Publisher To activate data transmission you must use transferStatus vi Read configuration Returns the first unprocessed configuration cluster received from Publisher After a connection is established Subscriber receives a remote system configuration with a description of analog channels and digital lines location and other system information Head customXML Data Returns the first unprocessed custom XML data received from Publisher Read customData Returns the first unprocessed custom data cluster received from Publisher Your application must be able to match the custom data received a variant value with the code specified by the application that sends the item discardData Throws all received alerts analog and digital data and configuration clusters awa transferStatus Set the status of transmission If you connect TRUE publisher start sending analog data and digital lines as soon as they are available on server side If you connect FALSE Publisher stop data transmission Alerts from publisher cannot be stopped Returns the count of unprocessed configuration cluster packets active otherwise is FALSE Returns a str
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