Search Results

Search found 3517 results on 141 pages for 'communication diagram'.

Page 19/141 | < Previous Page | 15 16 17 18 19 20 21 22 23 24 25 26  | Next Page >

  • Best method of achieving bi-directional communication between Apple iPad "clients" and a Windows Ser

    - by user361910
    We are currently starting to build a client-server system which will see 10 or more Apple iPad client devices communicating to a central Windows server over a wireless LAN. We wanted to some existing plumbing (.NET remoting/WCF/web services/etc) that would allow us to implement a reliable, secure solution without having to start at a low level (e.g. sockets) and recreate the wheel. One of the major requirements that complicates this scenario is that unlike a traditional web service, the windows server needs to be able to arbitrarily notify the clients whenever certain events occur -- so it is not a simple request/response scenario like the web. Initially, we were going to use Windows clients, so our plan was to use the full-duplex mode of .NET WCF over HTTP|TCP. But now using the iPad, we don't have any of the WCF infrastructure. So my question is: what is the best way to allow an iPad and a Windows server to (securely) communicate over a LAN, with each device able to initiate communication to the other? Am I stuck writing low-level socket code? Thanks!

    Read the article

  • ASP.NET 2.0 and COM Port Communication

    - by theaviator
    ASP.NET 2.0 and COM Port Communication Hello Guys, I have a managed DLL which communicates with the devices attached on COM/Serial ports. The desktop Winforms application sends requests on ports and receives/stores data in memory. In Winforms app I have added a reference to DLL and I am using the methods. This works well. Now, there is a situation where I need to show this data from serial/com port on a web-page. And also users should be able to send requests to the ports using this DLL. I have made a web app in ASP.NET (2.0). Added a reference to the DLL. I am able to use this DLL, the DLL communicates on the COM upon button click on web-page and also the response is shown on web page. However I am not happy with the approach and strongly feel that this is a bad approach. Also the development server crashes after 3 -4 requests. What is the best approach in this scenario. If I use a windows service then how would my ASP.net app will communicate with the Weindows service. Or can this be easily done using WCF. I have not used WCF any time nor any of .net remoting technique. Please suggest me the best architecture in this scenario. Thank you

    Read the article

  • Socket Communication in iPhone

    - by Timmi
    I have many images in iPhone. I have to send this images to server using a socket communication. what all we need to do to send the images to server through socket. If i use this code i can send string. what all should i change in the code so that i can send image through socket. I am new to network programming so some please help me to find a solution CFWriteStreamRef writeStream = NULL; CFStringRef host = CFSTR("192.168.1.211"); UInt32 port = 8001; CFStreamCreatePairWithSocketToHost(kCFAllocatorDef ault, host, port, NULL, &writeStream); CFWriteStreamSetProperty(writeStream, kCFStreamPropertyShouldCloseNativeSocket, kCFBooleanTrue); if(!CFWriteStreamOpen(writeStream)) { NSLog(@"Error Opening Socket"); } else{ UInt8 buf[] = "Hi !!!"; int bytesWritten = CFWriteStreamWrite(writeStream, buf, strlen((char*)buf)); NSLog(@"Written: %d", bytesWritten); if (bytesWritten < 0) { CFStreamError error = CFWriteStreamGetError(writeStream); } } Thanks,

    Read the article

  • How to change the behavior of string objects in web service calls via Windows Communication Foundati

    - by Geri Langlois
    I have third party api's which require string values to be submitted as empty strings. On an asp.net page I can use this code (abbreviated here) and it works fine: public class Customer { private string addr1 = ""; public string Addr1 { get {return addr1;} set {addr1 = value;} } private string addr2 = ""; public string Addr2 { get {return addr2;} set {addr2 = value;} } private string city = ""; public string City { get {return city;} set {city = value;} } } Customer cust = new Customer(); cust.Addr1 = "1 Main St."; cust.City = "Hartford"; int custno = CustomerController.InsertCustomer(cust); The Addr2 field, which was not initialized is still an empty string when inserted. However, using the same code but called it through a web service based on Windows Communication Foundation the Addr2 field is null. Is there a way (or setting) where all string fields, even if uninitialized, would return an empty string (unless, of course, a value was set).

    Read the article

  • Communication between lexer and parser

    - by FredOverflow
    Every time I write a simple lexer and parser, I stumble upon the same question: how should the lexer and the parser communicate? I see four different approaches: The lexer eagerly converts the entire input string into a vector of tokens. Once this is done, the vector is fed to the parser which converts it into a tree. This is by far the simplest solution to implement, but since all tokens are stored in memory, it wastes a lot of space. Each time the lexer finds a token, it invokes a function on the parser, passing the current token. In my experience, this only works if the parser can naturally be implemented as a state machine like LALR parsers. By contrast, I don't think it would work at all for recursive descent parsers. Each time the parser needs a token, it asks the lexer for the next one. This is very easy to implement in C# due to the yield keyword, but quite hard in C++ which doesn't have it. The lexer and parser communicate through an asynchronous queue. This is commonly known under the title "producer/consumer", and it should simplify the communication between the lexer and the parser a lot. Does it also outperform the other solutions on multicores? Or is lexing too trivial? Is my analysis sound? Are there other approaches I haven't thought of? What is used in real-world compilers? It would be really cool if compiler writers like Eric Lippert could shed some light on this issue.

    Read the article

  • Effective communication in a component-based system

    - by Tesserex
    Yes, this is another question about my game engine, which is coming along very nicely, with much thanks to you guys. So, if you watched the video (or didn't), the objects in the game are composed of various components for things like position, sprites, movement, collision, sounds, health, etc. I have several message types defined for "tell" type communication between entities and components, but this only goes so far. There are plenty of times when I just need to ask for something, for example an entity's position. There are dozens of lines in my code that look like this: SomeComponent comp = (SomeComponent)entity.GetComponent(typeof(SomeComponent)); if (comp != null) comp.GetSomething(); I know this is very ugly, and I know that casting smells of improper OO design. But as complex as things are, there doesn't seem to be a better way. I could of course "hard-code" my component types and just have SomeComponent comp = entity.GetSomeComponent(); but that seems like a cop-out, and a bad one. I literally JUST REALIZED, while writing this, after having my code this way for months with no solution, that a generic will help me. SomeComponent comp = entity.GetComponent<SomeComponent>(); Amazing how that works. Anyway, this is still only a semantic improvement. My questions remain. Is this actually that bad? What's a better alternative?

    Read the article

  • workaround for ORA-03113: end-of-file on communication channel

    - by Jefferstone
    The call to TEST_FUNCTION below fails with "ORA-03113: end-of-file on communication channel". A workaround is presented in TEST_FUNCTION2. I boiled down the code as my actual function is far more complex. Tested on Oracle 11G. Anyone have any idea why the first function fails? CREATE OR REPLACE TYPE "EMPLOYEE" AS OBJECT ( employee_id NUMBER(38), hire_date DATE ); CREATE OR REPLACE TYPE "EMPLOYEE_TABLE" AS TABLE OF EMPLOYEE; CREATE OR REPLACE FUNCTION TEST_FUNCTION RETURN EMPLOYEE_TABLE IS table1 EMPLOYEE_TABLE; table2 EMPLOYEE_TABLE; return_table EMPLOYEE_TABLE; BEGIN SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) < 'm' ) AS EMPLOYEE_TABLE) INTO table1 FROM dual; SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) >= 'm' ) AS EMPLOYEE_TABLE) INTO table2 FROM dual; SELECT CAST(MULTISET ( SELECT employee_id, hire_date FROM TABLE(table1) UNION SELECT employee_id, hire_date FROM TABLE(table2) ) AS EMPLOYEE_TABLE) INTO return_table FROM dual; RETURN return_table; END TEST_FUNCTION; CREATE OR REPLACE FUNCTION TEST_FUNCTION2 RETURN EMPLOYEE_TABLE IS table1 EMPLOYEE_TABLE; table2 EMPLOYEE_TABLE; return_table EMPLOYEE_TABLE; BEGIN SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) < 'm' ) AS EMPLOYEE_TABLE) INTO table1 FROM dual; SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) >= 'm' ) AS EMPLOYEE_TABLE) INTO table2 FROM dual; WITH combined AS ( SELECT employee_id, hire_date FROM TABLE(table1) UNION SELECT employee_id, hire_date FROM TABLE(table2) ) SELECT CAST(MULTISET ( SELECT * FROM combined ) AS EMPLOYEE_TABLE) INTO return_table FROM dual; RETURN return_table; END TEST_FUNCTION2; SELECT * FROM TABLE (TEST_FUNCTION()); -- Throws exception ORA-03113. SELECT * FROM TABLE (TEST_FUNCTION2()); -- Works

    Read the article

  • [java] tcp socket communication [send and recieve help]

    - by raven
    hello, I am creating a Chat in java. I have a method (onMouseRelease) inside an object that creates a tcp server and waits for a socket ServerSocket server = new ServerSocket(port); Socket channel = server.accept(); now I want to make a thread that will loop and read data from the socket, so that once the user on the other side sent me a string, I will extract the data from the socket [or is it called packet? sry I am new to this], and update a textbox to add the additional string from the socket [or packet?]. I have no idea how to READ (extract) the information from the scoket [/packet] and then update it into a JTextArea which is called userOutput. And how to Send a string to the other client, so that it will also could read the new data and update its JTextArea. (from what I know, for a 2 sided tcp communication you need one computer to host a server and the other to connect [as a client] and once the connection is set the client can also recieve new information from the socket. Is that true? and please tell me how ) Any help appreciated !! I know this is abit long but I have searched allot and didn't understand [I saw something like printwriter but failed to understand].

    Read the article

  • OS-independent Inter-program communication between Python and C

    - by Gyppo
    I have very little idea what I'm doing here, I've never done anything like this before, but a friend and I are writing competing chess programs and they need to be able to communicate to each other. He'll be writing mainly in C, the bulk of mine will be in Python, and I can see a few options: Alternately write to a temp file, or successive temp files. As the communication won't be in any way bulky this could work, but seems like an ugly work-around to me, the programs will have to keep checking for change/new files, it just seems ugly. Find some way of manipulating pipes i.e. mine.py| ./his . This seems like a bit of a dead end. Use sockets. But I don't know what I'd be doing, so could someone give me a pointer to some reading material? I'm not sure if there are OS-independent, language independent methods. Would there have to be some kind of supervisor server program to administrate? Use some kind of HTML protocol, which seems like overkill. I don't mind the programs having to run on the same machine. What do people recommend, and where can I start reading?

    Read the article

  • TCP socket communication

    - by raven
    hello, I am creating a Chat in java. I have a method (onMouseRelease) inside an object that creates a tcp server and waits for a socket like this: ServerSocket server = new ServerSocket(port); Socket channel = server.accept(); Now I want to make a thread that will loop and read data from the socket, so that once the user on the other side sends me a string, I will extract the data from the socket (or is it called packet? Sorry, I am new to this) and update a textbox to add the additional string from the socket (or packet?). I have no idea how to READ (extract) the information from the socket(/packet) and then update it into a JTextArea which is called userOutput. And how to send a string to the other client, so that it will also could read the new data and update its JTextArea. From what I know, for a 2 sided TCP communication you need one computer to host a server and the other to connect (as a client) and once the connection is set the client can also receive new information from the socket. Is that true? and please tell me how. Any help is appreciated! I know this is a bit long but I have searched a lot and didn't understand it (I saw something like PrintWriter but failed to understand).

    Read the article

  • Network communication for a turn based board game

    - by randooom
    Hi all, my first question here, so please don't be to harsh if something went wrong :) I'm currently a CS student (from Germany, if this info is of any use ;) ) and we got a, free selectable, programming assignment, which we have to write in a C++/CLI Windows Forms Application. My team, two others and me, decided to go for a network-compatible port of the board game Risk. We divided the work in 3 Parts, namely UI, game logic and network. Now we're on the part where we have to get everything working together and the big question mark is, how to get the clients synchronized with each other? Our approach so far is, that each client has all information necessary to calculate and/or execute all possible actions. Actually the clients have all information available at all, aside from the game-initializing phase (add players, select map, etc.), which needs one "super-client" with some extra stuff to control things. This is the standard scenario of our approach: player performs action, the action is valid and got executed on the players client action is sent over the network action is executed on the other clients The design (i.e. no or code so far) we came up with so far, is something like the following pseudo sequence diagram. Gui, Controller and Network implement all possible actions (i.e. all actions which change data) as methods from an interface. So each part can implement the method in a way to get their job done. Example with Action(): On the player side's Client: Player-->Gui.Action() Gui-->Controller.Action() Controller-->Logic.Action (Logic.Action() == NoError)? Controller-->Network.Action() Network-->Parser.ParseAction() Network.Send(msg) On all other clients: Network.Recv(msg) Network-->Parser.Deparse(msg) Parser-->Logic.Action() Logic-->Gui.Action() The questions: Is this a viable approach to our task? Any better/easier way to this? Recommendations, critique? Our knowledge (so you can better target your answer): We are on the beginner side, in regards to programming on a somewhat larger projects with a small team. All of us have some general programming experience and basic understanding of the .Net Libraries and Windows Forms. If you need any further information, please feel free to ask.

    Read the article

  • How would you communicate with aliens as a computer scientist?

    - by Pyrolistical
    Let's say aliens arrive on Earth and instead of just sending mathematicians and linguistic experts governments around the work decide to send an expert of major field. After a quick round of sorting you are paired up with an alien computer scientist. Given you don't understand each others language how would you using computer science to start the ground work of communication? eg. We know binary is universal, but not the way we write it. The symbols are not universal nor is the the direction we write it (MSB vs LSB and left vs right) Assume aliens are "similar" to us physically it won't impede visual communication.

    Read the article

  • New programming jargon you coined?

    - by jdk
    What programming terms have you coined that have taken off in your own circles? (i.e. have heard others repeating it?) It might be within your own team, workplace or garnered greater popularity on the Internet. Define your programming term, word or phrase in bold followed by an explanation, citation and/or usage example so we can use it in appropriate context. This question serves in the spirit of communication among programmers through sharing of terminology with each other, to benefit us by its propagation within our own teams and environments. Please no repeats of common jargon already ingrained in the programming culture like: "kludge", "automagically", "cruft", etc. (unless you coined it). Stealing from the comments: A shared vocabulary is the basis of communication, not just among programmers, Note: This Programming question has been reworded/reorganized to phrase a real question and remove ambiguity, vagueness and rhetorical device. It is not difficult to know what is being asked & question can be reasonably answered (see answers below).

    Read the article

  • Constraints when using WCF for an online multiplayer game

    - by Etan
    I want to build a service oriented game server and client using WCF where users can play card games on different tables after they logged in with an account. I would like to choose WCF due to it's flexibility in exchanging the communication channels. Maybe, a web interface will be added later which can then just use an other channel class. An additional plus is the ability for contexts which could be used to track a user over a whole gaming session. Are there some constraints I should be aware of when using WCF for the communication between the client and the server?

    Read the article

  • Write a serverside c++/openGL App, that is accessible via JavaScript

    - by moka
    Hi, I am currently having an idea where I want to save an image from a c++/openGL application on demand from a browser. So basically I would like to run the application itself on the server and have a simple communication layer like this: JS - tell application to do calculations (and maybe pass a string or some simple data) application - tell JS when finished and maybe send a link, text or something as simple as that. I don't really have alot of experience with webservers and as such don't know if that is possible at all (it's just my naive thinking). And note: I am not talking about a webGL application, I just want to have simple communication between a c++ serverside application, and the user. Any ideas how to do that? Thanks alot!

    Read the article

  • MSDTC - Communication with the underlying transaction manager has failed (Firewall open, MSDTC netwo

    - by SocialAddict
    I'm having problems with my ASP.NET web forms system. It worked on our test server but now we are putting it live one of the servers is within a DMZ and the SQL server is outside of that (on our network still though - although a different subnet) I have open up the firewall completely between these two boxes to see if that was the issue and it still gives the error message "Communication with the underlying transaction manager has failed" whenever we try and use the "TransactionScope". We can access the data for retrieval it's just transactions that break it. We have also used msdtc ping to test the connection and with the amendments on the firewall that pings successfully, but the same error occurs! How do i resolve this error? Any help would be great as we have a system to go live today. Panic :) Edit: I have created a more straightforward test page with a transaction as below and this works fine. Could a nested transaction cause this kind of error and if so why would this only cause an issue when using a live box in a dmz with a firewall? AuditRepository auditRepository = new AuditRepository(); try { using (TransactionScope scope = new TransactionScope()) { auditRepository.Add(DateTime.Now, 1, "TEST-TRANSACTIONS#1", 1); auditRepository.Save(); auditRepository.Add(DateTime.Now, 1, "TEST-TRANSACTIONS#2", 1); auditRepository.Save(); scope.Complete(); } } catch (Exception ex) { Response.Write("Test Error For Transaction: " + ex.Message + "<br />" + ex.StackTrace); } This is the ErrorStack we are getting when the problem occurs: at System.Transactions.TransactionInterop.GetOletxTransactionFromTransmitterPropigationToken(Byte[] propagationToken) at System.Transactions.TransactionStatePSPEOperation.PSPEPromote(InternalTransaction tx) at System.Transactions.TransactionStateDelegatedBase.EnterState(InternalTransaction tx) at System.Transactions.EnlistableStates.Promote(InternalTransaction tx) at System.Transactions.Transaction.Promote() at System.Transactions.TransactionInterop.ConvertToOletxTransaction(Transaction transaction) at System.Transactions.TransactionInterop.GetExportCookie(Transaction transaction, Byte[] whereabouts) at System.Data.SqlClient.SqlInternalConnection.GetTransactionCookie(Transaction transaction, Byte[] whereAbouts) at System.Data.SqlClient.SqlInternalConnection.EnlistNonNull(Transaction tx) at System.Data.SqlClient.SqlInternalConnection.Enlist(Transaction tx) at System.Data.SqlClient.SqlInternalConnectionTds.Activate(Transaction transaction) at System.Data.ProviderBase.DbConnectionInternal.ActivateConnection(Transaction transaction) at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open() at System.Data.Linq.SqlClient.SqlConnectionManager.UseConnection(IConnectionUser user) at System.Data.Linq.SqlClient.SqlProvider.get_IsSqlCe() at System.Data.Linq.SqlClient.SqlProvider.InitializeProviderMode() at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query) at System.Data.Linq.ChangeDirector.StandardChangeDirector.DynamicInsert(TrackedObject item) at System.Data.Linq.ChangeDirector.StandardChangeDirector.Insert(TrackedObject item) at System.Data.Linq.ChangeProcessor.SubmitChanges(ConflictMode failureMode) at System.Data.Linq.DataContext.SubmitChanges(ConflictMode failureMode) at System.Data.Linq.DataContext.SubmitChanges() at RegBook.classes.DbBase.Save() at RegBook.usercontrols.BookingProcess.confirmBookingButton_Click(Object sender, EventArgs e)

    Read the article

  • Microsoft lance Office 365 pour l'éducation, et ouvre le service collaboratif et de communication Cloud à de nouveaux marchés

    Microsoft lance Office 365 pour l'éducation et ouvre le service collaboratif et de communication Cloud à de nouveaux marchés Microsoft vient d'annoncer le lancement officiel d'une version «Éducation » de son service Cloud Office 365, et une ouverture de celui-ci à de nouveaux marchés. Office 365 est une suite d'applications professionnelles de collaboration et de communication en mode Cloud dont Exchange Online (pour la messagerie), Lync Online (pour la gestion des contacts et la messagerie instantanée), SharePoint Online (pour l'édition des sites) et les Office Web Apps (versions hébergées de Word, Excel, PowerPoint et OneNote). [IMG]http://rdonfack.developpez.com/images/Office365...

    Read the article

  • Word 2007 Smart Arts - how deep can I go?

    - by Franz
    In Office Word 2007, I want to use a Smart Art to create a hierarchical diagram for an organization. I want to use the one called "simple radial" (at least that's my word-to-word translation from German - it's the one with the circle in the middle and other circles around it, attached by lines). However, it seems to only support one level of depth (at least for circles). Everything else just becomes a bulleted list inside of the circle. Is there any way to accomplish this in Word 2007? Else: are there any other free tools to do this? I also want to add some other shapes. Again: I want to accomplish a star-like structure with a total of 4 depth levels. Thanks for your responses in advance!

    Read the article

  • Visio Losing My Diagrams!

    - by bobber205
    I've created under "Static Model-Top Package" 4 different sequence diagrams. Once I tried creating the fifth it won't keep it. I try to double click and open it and it opens the 4th one. I can delete the 5th one and create a new one. I can edit this but as soon as I go to another diagram, I've lost it and can only go back to the 4th one and edit that even though I right clicked the 5th one and selected "Open Sequence". What is going on? Has anyone else seen this Visio issue?

    Read the article

  • Looking for best practise for writing a serial device communication app in C#

    - by cdotlister
    I am pretty new to serial comms, but would like advise on how to best achieve a robust application which speak to and listens to a serial device. I have managed to make use of System.IO.serialport, and successfully connected to, sent data to and recieved from my device. The way things work is this. My application connects to the Com Port and opens the port.... I then connect my device to the com port, and it detects a connectio to the PC, so sends a bit of text. it's really just copyright info, as well as the version of the firmware. I don't do anything with that, except display it in my 'activity' window. The device then waits. I can then query information, but sending a command such as 'QUERY PARAMETER1'. It then replies with something like: 'QUERY PARAMETER1\r\n\r\n76767\r\n\r\n' I then process that. I can then update it by sending 'SET PARAMETER1 12345', and it will reply with 'QUERY PARAMETER1\r\n\r\n12345\r\n\r\n'. All pretty basic. So, what I have done is created a Communication Class. this call is called in it's own thread, and sends data back to the main form... and also allows me to send messages to it. Sending data is easy. Recieving is a bit more tricky. I have employed the use of the datarecieved event, and when ever data comes in, I echo that to my screen. My problem is this: When I send a command, I feel I am being very dodgy in my handling. What I am doing is, lets say I am sending 'QUERY PARAMETER1'. I send the command to the device, I then put 'PARAMETER1' into a global variable, and I do a Thread.Sleep(100). On the data recieved, I then have a bit of logic that checks the incoming data, and sees if the string CONTAINS the value in the gloabl variable. As the reply may be 'QUERY PARAMETER1\r\n\r\n76767\r\n\r\n', it sees that it contains my parameter, parses the string, and returns the value I am looking for, but placing it into another global variable. My sending method was sleeping for 100ms. It then wakes, and checks the returned global variable. If it has data... then I'm happy, and I process the data. Problem is... if the sleep is too short.. it will fail. And I feel it's flakey.. putting stuff into variables.. then waiting... The other option is to use ReadLine instead, but that's very blocking. So I remove the datarecieved method, and instead... just send the data... then call ReadLine(). That may give me better results. There's no time, except when we connect initially, that data comes from the device, without me requesting it. So, maybe readline will be simpler and safer? Is this known as 'Blocking' reads? Also, can I set a timeout? Hopefully someone can guide me.

    Read the article

  • Looking for best practise for writing a serial device communication app

    - by cdotlister
    I am pretty new to serial comms, but would like advise on how to best achieve a robust application which speak to and listens to a serial device. I have managed to make use of System.IO.SerialPort, and successfully connected to, sent data to and recieved from my device. The way things work is this. My application connects to the Com Port and opens the port.... I then connect my device to the com port, and it detects a connection to the PC, so sends a bit of text. it's really just copyright info, as well as the version of the firmware. I don't do anything with that, except display it in my 'activity' window. The device then waits. I can then query information, but sending a command such as 'QUERY PARAMETER1'. It then replies with something like: 'QUERY PARAMETER1\r\n\r\n76767\r\n\r\n' I then process that. I can then update it by sending 'SET PARAMETER1 12345', and it will reply with 'QUERY PARAMETER1\r\n\r\n12345\r\n\r\n'. All pretty basic. So, what I have done is created a Communication Class. this call is called in it's own thread, and sends data back to the main form... and also allows me to send messages to it. Sending data is easy. Recieving is a bit more tricky. I have employed the use of the datarecieved event, and when ever data comes in, I echo that to my screen. My problem is this: When I send a command, I feel I am being very dodgy in my handling. What I am doing is, lets say I am sending 'QUERY PARAMETER1'. I send the command to the device, I then put 'PARAMETER1' into a global variable, and I do a Thread.Sleep(100). On the data received, I then have a bit of logic that checks the incoming data, and sees if the string CONTAINS the value in the global variable. As the reply may be 'QUERY PARAMETER1\r\n\r\n76767\r\n\r\n', it sees that it contains my parameter, parses the string, and returns the value I am looking for, but placing it into another global variable. My sending method was sleeping for 100ms. It then wakes, and checks the returned global variable. If it has data... then I'm happy, and I process the data. Problem is... if the sleep is too short.. it will fail. And I feel it's flaky.. putting stuff into variables.. then waiting... The other option is to use ReadLine instead, but that's very blocking. So I remove the data received method, and instead... just send the data... then call ReadLine(). That may give me better results. There's no time, except when we connect initially, that data comes from the device, without me requesting it. So, maybe ReadLine will be simpler and safer? Is this known as 'Blocking' reads? Also, can I set a timeout? Hopefully someone can guide me.

    Read the article

  • Synchronous communication using NSOperationQueue

    - by chip_munks
    I am new to Objective C programming. I have created two threads called add and display using the NSInvocationOperation and added it on to the NSOperationQueue. I make the display thread to run first and then run the add thread. The display thread after printing the "Welcome to display" has to wait for the results to print from the add method. So i have set the waitUntilFinished method. Both the Operations are on the same queue. If i use waitUntilFinished for operations on the same queue there may be a situation for deadlock to happen(from apples developer documentation). Is it so? To wait for particular time interval there is a method called waitUntilDate: But if i need to like this wait(min(100,dmax)); let dmax = 20; How to do i wait for these conditions? It would be much helpful if anyone can explain with an example. EDITED: threadss.h ------------ #import <Foundation/Foundation.h> @interface threadss : NSObject { BOOL m_bRunThread; int a,b,c; NSOperationQueue* queue; NSInvocationOperation* operation; NSInvocationOperation* operation1; NSConditionLock* theConditionLock; } -(void)Thread; -(void)add; -(void)display; @end threadss.m ------------ #import "threadss.h" @implementation threadss -(id)init { if (self = [super init]) { queue = [[NSOperationQueue alloc]init]; operation = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(display) object:nil]; operation1 = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(add) object:nil]; theConditionLock = [[NSConditionLock alloc]init]; } return self; } -(void)Thread { m_bRunThread = YES; //[operation addDependency:operation1]; if (m_bRunThread) { [queue addOperation:operation]; } //[operation addDependency:operation1]; [queue addOperation:operation1]; //[self performSelectorOnMainThread:@selector(display) withObject:nil waitUntilDone:YES]; //NSLog(@"I'm going to do the asynchronous communication btwn the threads!!"); //[self add]; //[operation addDependency:self]; sleep(1); [queue release]; [operation release]; //[operation1 release]; } -(void)add { NSLog(@"Going to add a and b!!"); a=1; b=2; c = a + b; NSLog(@"Finished adding!!"); } -(void)display { NSLog(@"Into the display method"); [operation1 waitUntilFinished]; NSLog(@"The Result is:%d",c); } @end main.m ------- #import <Foundation/Foundation.h> #import "threadss.h" int main (int argc, const char * argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; threadss* thread = [[threadss alloc]init]; [thread Thread]; [pool drain]; return 0; } This is what i have tried with a sample program. output 2011-06-03 19:40:47.898 threads_NSOperationQueue[3812:1503] Going to add a and b!! 2011-06-03 19:40:47.898 threads_NSOperationQueue[3812:1303] Into the display method 2011-06-03 19:40:47.902 threads_NSOperationQueue[3812:1503] Finished adding!! 2011-06-03 19:40:47.904 threads_NSOperationQueue[3812:1303] The Result is:3 Is the way of invoking the thread is correct. 1.Will there be any deadlock condition? 2.How to do wait(min(100,dmax)) where dmax = 50.

    Read the article

  • Communication with HyperTerminal [ QT and WINApi ]

    - by javaAmator
    Hi! I write program to communicate with modem (it useing Hayes commands) and this is working. GUI is programmed with QT, but communication with COM port is write with winapi library. I have problem when I want to send with my program message from one computer to another, i can't send Polish chars (they are repleaced by '?'), how can I fix it ? Does anyone have idea ?? And I have one more problem, I can't send message from my program to Microsoft HyperTerminal, HyperTerminal receive something, but not that what I send. Thx for any help :) Important pieces of code: Connect with port: portHandle = CreateFile (portName, GENERIC_WRITE | GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL); GetCommState (portHandle, &dcb); switch(ui->comboBox->currentIndex()) { case 0 : dcb.BaudRate=CBR_110; break; case 1 : dcb.BaudRate=CBR_300; break; case 2 : dcb.BaudRate=CBR_600; break; case 3 : dcb.BaudRate=CBR_1200; break; case 4 : dcb.BaudRate=CBR_2400; break; case 5 : dcb.BaudRate=CBR_4800; break; case 6 : dcb.BaudRate=CBR_9600; break; case 7 : dcb.BaudRate=CBR_14400; break; case 8 : dcb.BaudRate=CBR_19200; break; case 9 : dcb.BaudRate=CBR_38400; break; case 10 : dcb.BaudRate=CBR_56000; break; case 11 : dcb.BaudRate=CBR_57600; break; case 12 : dcb.BaudRate=CBR_115200; break; case 13 : dcb.BaudRate=CBR_128000; break; case 14 : dcb.BaudRate=CBR_256000; break; } dcb.fBinary = TRUE; dcb.fParity = TRUE; dcb.fOutxCtsFlow = FALSE; dcb.fOutxDsrFlow = FALSE; dcb.fDtrControl = DTR_CONTROL_ENABLE; dcb.fDsrSensitivity = FALSE; dcb.fTXContinueOnXoff = TRUE; dcb.fOutX = FALSE; dcb.fInX = FALSE; dcb.fErrorChar = FALSE; dcb.fNull = FALSE; dcb.fRtsControl = RTS_CONTROL_ENABLE; dcb.fAbortOnError = FALSE; //dcb.ByteSize = dataBits; dcb.DCBlength = sizeof (DCB); switch(ui->comboBox_3->currentIndex()) { case 1 : dcb.Parity = EVENPARITY; break; case 3 : dcb.Parity = MARKPARITY; break; case 2 : dcb.Parity = ODDPARITY; break; case 4 : dcb.Parity = SPACEPARITY; break; case 0 : dcb.Parity = NOPARITY; break; } switch (ui->comboBox_4->currentIndex()) { case 0 : dcb.StopBits = ONESTOPBIT; break; case 1 : dcb.StopBits = ONE5STOPBITS;break; case 2 : dcb.StopBits = TWOSTOPBITS; break; } switch (ui->comboBox_2->currentIndex()) { case 0 : dcb.ByteSize = 5; break; case 1 : dcb.ByteSize = 6;break; case 2 : dcb.ByteSize= 7; break; case 3 : dcb.ByteSize = 8; break; } SetCommState (portHandle, &dcb); GetCommTimeouts (portHandle, &CommTimeouts); CommTimeouts.ReadIntervalTimeout = MAXDWORD; CommTimeouts.ReadTotalTimeoutMultiplier = 0; CommTimeouts.ReadTotalTimeoutConstant = 0; CommTimeouts.WriteTotalTimeoutMultiplier = 10; CommTimeouts.WriteTotalTimeoutConstant = 1000; SetCommTimeouts (portHandle, &CommTimeouts); Send MSG: void MainWindow::Send(char c) { do {WriteFile(portHandle, &c, 1, &cbWritten, NULL); } while (!(cbWritten)); } void MainWindow::on_pushButton_clicked() { QString str = ui->lineEdit->text(); std::string str2; ui->lineEdit->clear(); str2 = str.toStdString(); for(int i=0; i < str2.size();i++) { Send(str2[i]); //qDebug()<< str2[i]; } Send(char(13)); } Receive MSG: void ReaderThread::run() { char c; while(1) { c = Receive(); if(c==13) { emit insertPlainText("\n"); } else { emit insertPlainText(QString(c)); } } } char ReaderThread::Receive() { char c; do{ ReadFile(portHandle, &c, 1, &cbRead, NULL); } while (!(cbRead)); return c; }

    Read the article

  • Duplex communication using NetTcpBinding - ContractFilter mismatch?

    - by Shaul
    I'm making slow and steady progress towards having a duplex communication channel open between a client and a server, using NetTcpBinding. (FYI, you can observe my newbie progress here and here!) I'm now at the stage where I have successfully connected to my server, through the server's firewall, and the client can make requests of the server. In the other direction, however, things aren't quite so happy. It works fine when testing on my own machine, but when testing over the internet, when I try to initiate a callback from the server side, I get an error: The message with Action 'http://MyWebService/IWebService/HelloWorld' cannot be processed at the receiver, due to a ContractFilter mismatch at the EndpointDispatcher. This may be because of either a contract mismatch (mismatched Actions between sender and receiver) or a binding/security mismatch between the sender and the receiver. Check that sender and receiver have the same contract and the same binding (including security requirements, e.g. Message, Transport, None). Here are some of the key bits of code. First, the web interface: [ServiceContract(Namespace = "http://MyWebService", SessionMode = SessionMode.Required, CallbackContract = typeof(ISiteServiceExternal))] public interface IWebService { [OperationContract] void Register(long customerID); } public interface ISiteServiceExternal { [OperationContract] string HelloWorld(); } Then, on the client side (I was fiddling with these attributes without really knowing what I'm doing): [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession, Namespace="http://MyWebService")] class SiteServer : IWebServiceCallback { string IWebServiceCallback.HelloWorld() { return "Hello World!"; } ... } So what am I doing wrong here? EDIT: Adding app.config code. From server: <system.serviceModel> <diagnostics> <messageLogging logMalformedMessages="true" logMessagesAtServiceLevel="true" logMessagesAtTransportLevel="true" logEntireMessage="true" maxMessagesToLog="1000" maxSizeOfMessageToLog="524288" /> </diagnostics> <behaviors> <serviceBehaviors> <behavior name="mex"> <serviceDebug includeExceptionDetailInFaults="true"/> <serviceMetadata/> </behavior> </serviceBehaviors> </behaviors> <services> <service name ="MyWebService.WebService" behaviorConfiguration="mex"> <endpoint address="net.tcp://localhost:8000" binding="netTcpBinding" contract="MyWebService.IWebService" bindingConfiguration="TestBinding" name="MyEndPoint"></endpoint> <endpoint address ="mex" binding="mexTcpBinding" name="MEX" contract="IMetadataExchange"/> <host> <baseAddresses> <add baseAddress="net.tcp://localhost:8000"/> </baseAddresses> </host> </service> </services> <bindings> <netTcpBinding> <binding name="TestBinding" maxBufferPoolSize="524288" maxReceivedMessageSize="65536" portSharingEnabled="false"> <readerQuotas maxDepth="32" maxStringContentLength ="8192" maxArrayLength ="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384"/> <security mode="None"/> </binding> </netTcpBinding> </bindings> </system.serviceModel> and on the client side: <system.serviceModel> <bindings> <netTcpBinding> <binding name="MyEndPoint" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" transactionFlow="false" transferMode="Buffered" transactionProtocol="OleTransactions" hostNameComparisonMode="StrongWildcard" listenBacklog="10" maxBufferPoolSize="524288" maxBufferSize="65536" maxConnections="10" maxReceivedMessageSize="65536"> <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" /> <reliableSession ordered="true" inactivityTimeout="00:10:00" enabled="false" /> <security mode="None"> <transport clientCredentialType="Windows" protectionLevel="EncryptAndSign"> <extendedProtectionPolicy policyEnforcement="Never" /> </transport> <message clientCredentialType="Windows" /> </security> </binding> </netTcpBinding> </bindings> <client> <endpoint address="net.tcp://mydomain.gotdns.com:8000/" binding="netTcpBinding" bindingConfiguration="MyEndPoint" contract="IWebService" name="MyEndPoint" /> </client> </system.serviceModel>

    Read the article

< Previous Page | 15 16 17 18 19 20 21 22 23 24 25 26  | Next Page >