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  • Filtering serial port io

    - by mr odus
    I am currently working on a project where I communicate with hardware via a com port on its respective pc(win xp or 7) It is a fairly large project and sifting through the log file can be a bit of pain. This is my current setup. I use putty to do the actual serial communication, and write it to a log file. Then using MinGW Msys I filter it using tail -f "puttyLog" | grep -i "search term" Is there a better way to do this? I mean specifically filtering the input in realtime. Not that mine is terrible, but it still involves having to read from a log and sometimes there have been hangups where it will be delayed for a minute or 2. I have used software in the past with a main io window and then internal filter panels, but can no longer remember or find it.

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  • Configure PL2303-based USB-to-RS232 adapter to stay awake when no active device is present

    - by casualuser
    I am resurrecting some X10 devices with the aid of a USB-to-RS232 adapter. The problem is, that the adapter only works with the Firecracker device when there is another serial device on the line (the Firecracker is a pass-through device that monitors the RTS and DTR lines to do its magic). Is the PL2303 going to sleep without a real device on the line? Is there an option or command to keep it awake? Is there a cable configuration that would make it work without a real serial device present?

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  • How to set up a serial connection to a Windows 7 computer

    - by oli_arborum
    I need to set up a "dial in" connection to a Windows 7 (Ultimate) computer via a serial null-modem cable to be able to connect from a Windows XP client to that computer and exchange data over IP. Question 1: How do I do that? I did neither find the information via Google nor in the MSDN. Seems like no one tried ever before... ;-) I already managed to install a legacy modem device called "Communications cable between two computers" and found the menu entry "New Incoming Connection..." in Network and Internet Network Connections. When I finish this wizard I get the message that the "Routing and Remote Access service" cannot be started. In the event viewer I see the following error messages: "The currently configured authentication provider failed to load and initialize successfully. The requested name is valid, but no data of the requested type was found." (Source: RemoteAccess, EventID: 20152) "The Routing and Remote Access service terminated with service-specific error The requested name is valid, but no data of the requested type was found." (Source: Service Control Manager, EventID: 7024) The Windows 7 installation is "naked", i.e. no additional software or services are installed. Question 2: Am I on the right path to set up the connection? Question 3: How can I get the Routing and Remote Access service running?

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  • What does opening a serial port do?

    - by reve_etrange
    What does opening the standard PC serial port do, in electrical terms (i.e. what voltages on which pins)? For example, the ancient VB6 program which controls an apparatus I am tasked with maintaining toggles .PortOpen to control some TTL. The connection only used 2 pins (bad solders fell apart), so which pins do I solder to? The only labels / documentation refer to pins 7 and 9, saying 0V and 5V parenthetically, but does .PortOpen really just put 5V between RI and RTS?. As a post script, this isn't the weirdest thing about the set up. The TTL I referred to above also connects to an instrument via a BNC to DB9 (!), with only 1 pin used. I guess there was an assumption about a common ground, since the BNC shielding isn't connected to the GND pin? The connection is to the instrument's 'foot pedal' pin, it was a way to remotely trigger the device. Update According to this page, the DTR and RTS pins can go high when the port is opened. If they were so configured, they will subsequently go low when the port is closed. If DTR and RTS are not enabled, opening the port should set both to low (and keep them low).

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  • Adjust parameters of serial port reading

    - by clinisbut
    Hello. I'm facing a particular issue that regards serial communication under win32. I'm communicating with a device can only accept frames when it is not already communicating. So I must find a valid frame and then inmediatelly send my request. I developed a class named Serial that handles basic operations on serial port (open, close, read, write) and then a Thread calls inside a loop read and write functions. Thread loop //Device is an object of class Serial while( device->isOpen() && !terminate ) { unsigned int readed = 0; unsigned long error = ERROR_SUCCESS; unsigned char* data = device->read( &readed, &error ); if( error==ERROR_SUCCESS ) { //If data received, deliver to upper level if( readed>0 ) { QByteArray output( (const char*)data, (signed int)readed ); emit dataArrived( output, readed ); } } else { //unrelated stuff } //Here I manage the writting issue //Only when nothing is received, and Upper layer wants to send a frame //(Upper layer only will mark as something to send when it detects a valid frame) if( readed==0 ) { out_lock.lock(); //If something to send... if( something_to_send > 0 ) { if( device->write( output_buffer, output_size, &error ) ) { //things... } } } } The Thread basically keeps reading, and when nothing is received, sees if somebody has signaled to send a frame (this means that a valid frame is just received). When this happens, it writes the frame through serial port. Here comes my problem. Inside the Serial::read() function: I use the overlapped way of reading: ::ClearCommError( handle, &dwErrors, &stat); if( stat.cbInQue ) { //If there's something to read, read it, please note the bytes to read parameter, here 1. bool ok = ::ReadFile( handle, buffer_in, 1, &bytes_read, &ov_reader ); if( !ok ) { DWORD _error = ::GetLastError(); if( _error == ERROR_IO_PENDING ) { DWORD result = ::WaitForMultipleObjects( 2, waiters, FALSE,INFINITE ); switch( result ) { //Eventshutdown case WAIT_OBJECT_0: /*code omitted*/break; case WAIT_OBJECT_0+1: ok = ::GetOverlappedResult( handle, &ov_reader, &bytes_read, true ); //check ok value omitted break; } } } } if( bytes_read>0 ) { *size = bytes_read; } Here starts my problem. When device sends me small frames (around 30 bytes) everything works fine, but when larger frames are sent, the code is not able to find any free time between frames causing the thread to never be able send any frame because readed is never 0. If I increase the number of bytes to read inside the read() function, lose the ability to detect when the device "listens": bool ok = ::ReadFile(handle, buffer_in, 50, &bytes_read, &ov_reader ); This happens because my app can receive the end of a frame together with the start of the next one. This behaviour is very common. In the other hand, if I change the INFINITE argument by a valid timeout in the WaitForMultipleObjects function, I lose data. So my question basically is... what I'm doing wrong? Why when reading 1 byte each time I don't find any free time to send my own frames? Thank you

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  • how to use serial port in UDK using windows DLL and DLLBind directive?

    - by Shayan Abbas
    I want to use serial port in UDK, For that purpose i use a windows DLL and DLLBind directive. I have a thread in windows DLL for serial port data recieve event. My problem is: this thread doesn't work properly. Please Help me. below is my code SerialPortDLL Code: // SerialPortDLL.cpp : Defines the exported functions for the DLL application. // #include "stdafx.h" #include "Cport.h" extern "C" { // This is an example of an exported variable //SERIALPORTDLL_API int nSerialPortDLL=0; // This is an example of an exported function. //SERIALPORTDLL_API int fnSerialPortDLL(void) //{ // return 42; //} CPort *sp; __declspec(dllexport) void Open(wchar_t* portName) { sp = new CPort(portName); //MessageBox(0,L"ha ha!!!",L"ha ha",0); //MessageBox(0,portName,L"ha ha",0); } __declspec(dllexport) void Close() { sp->Close(); MessageBox(0,L"ha ha!!!",L"ha ha",0); } __declspec(dllexport) wchar_t *GetData() { return sp->GetData(); } __declspec(dllexport) unsigned int GetDSR() { return sp->getDSR(); } __declspec(dllexport) unsigned int GetCTS() { return sp->getCTS(); } __declspec(dllexport) unsigned int GetRing() { return sp->getRing(); } } CPort class code: #include "stdafx.h" #include "CPort.h" #include "Serial.h" CSerial serial; HANDLE HandleOfThread; LONG lLastError = ERROR_SUCCESS; bool fContinue = true; HANDLE hevtOverlapped; HANDLE hevtStop; OVERLAPPED ov = {0}; //char szBuffer[101] = ""; wchar_t *szBuffer = L""; wchar_t *data = L""; DWORD WINAPI ThreadHandler( LPVOID lpParam ) { // Keep reading data, until an EOF (CTRL-Z) has been received do { MessageBox(0,L"ga ga!!!",L"ga ga",0); //Sleep(10); // Wait for an event lLastError = serial.WaitEvent(&ov); if (lLastError != ERROR_SUCCESS) { //LOG( " Unable to wait for a COM-port event" ); } // Setup array of handles in which we are interested HANDLE ahWait[2]; ahWait[0] = hevtOverlapped; ahWait[1] = hevtStop; // Wait until something happens switch (::WaitForMultipleObjects(sizeof(ahWait)/sizeof(*ahWait),ahWait,FALSE,INFINITE)) { case WAIT_OBJECT_0: { // Save event const CSerial::EEvent eEvent = serial.GetEventType(); // Handle break event if (eEvent & CSerial::EEventBreak) { //LOG( " ### BREAK received ###" ); } // Handle CTS event if (eEvent & CSerial::EEventCTS) { //LOG( " ### Clear to send %s ###", serial.GetCTS() ? "on":"off" ); } // Handle DSR event if (eEvent & CSerial::EEventDSR) { //LOG( " ### Data set ready %s ###", serial.GetDSR() ? "on":"off" ); } // Handle error event if (eEvent & CSerial::EEventError) { switch (serial.GetError()) { case CSerial::EErrorBreak: /*LOG( " Break condition" );*/ break; case CSerial::EErrorFrame: /*LOG( " Framing error" );*/ break; case CSerial::EErrorIOE: /*LOG( " IO device error" );*/ break; case CSerial::EErrorMode: /*LOG( " Unsupported mode" );*/ break; case CSerial::EErrorOverrun: /*LOG( " Buffer overrun" );*/ break; case CSerial::EErrorRxOver: /*LOG( " Input buffer overflow" );*/ break; case CSerial::EErrorParity: /*LOG( " Input parity error" );*/ break; case CSerial::EErrorTxFull: /*LOG( " Output buffer full" );*/ break; default: /*LOG( " Unknown" );*/ break; } } // Handle ring event if (eEvent & CSerial::EEventRing) { //LOG( " ### RING ###" ); } // Handle RLSD/CD event if (eEvent & CSerial::EEventRLSD) { //LOG( " ### RLSD/CD %s ###", serial.GetRLSD() ? "on" : "off" ); } // Handle data receive event if (eEvent & CSerial::EEventRecv) { // Read data, until there is nothing left DWORD dwBytesRead = 0; do { // Read data from the COM-port lLastError = serial.Read(szBuffer,33,&dwBytesRead); if (lLastError != ERROR_SUCCESS) { //LOG( "Unable to read from COM-port" ); } if( dwBytesRead == 33 && szBuffer[0]=='$' ) { // Finalize the data, so it is a valid string szBuffer[dwBytesRead] = '\0'; ////LOG( "\n%s\n", szBuffer ); data = szBuffer; } } while (dwBytesRead > 0); } } break; case WAIT_OBJECT_0+1: { // Set the continue bit to false, so we'll exit fContinue = false; } break; default: { // Something went wrong //LOG( "Error while calling WaitForMultipleObjects" ); } break; } } while (fContinue); MessageBox(0,L"kka kk!!!",L"kka ga",0); return 0; } CPort::CPort(wchar_t *portName) { // Attempt to open the serial port (COM2) //lLastError = serial.Open(_T(portName),0,0,true); lLastError = serial.Open(portName,0,0,true); if (lLastError != ERROR_SUCCESS) { //LOG( "Unable to open COM-port" ); } // Setup the serial port (115200,8N1, which is the default setting) lLastError = serial.Setup(CSerial::EBaud115200,CSerial::EData8,CSerial::EParNone,CSerial::EStop1); if (lLastError != ERROR_SUCCESS) { //LOG( "Unable to set COM-port setting" ); } // Register only for the receive event lLastError = serial.SetMask(CSerial::EEventBreak | CSerial::EEventCTS | CSerial::EEventDSR | CSerial::EEventError | CSerial::EEventRing | CSerial::EEventRLSD | CSerial::EEventRecv); if (lLastError != ERROR_SUCCESS) { //LOG( "Unable to set COM-port event mask" ); } // Use 'non-blocking' reads, because we don't know how many bytes // will be received. This is normally the most convenient mode // (and also the default mode for reading data). lLastError = serial.SetupReadTimeouts(CSerial::EReadTimeoutNonblocking); if (lLastError != ERROR_SUCCESS) { //LOG( "Unable to set COM-port read timeout" ); } // Create a handle for the overlapped operations hevtOverlapped = ::CreateEvent(0,TRUE,FALSE,0);; if (hevtOverlapped == 0) { //LOG( "Unable to create manual-reset event for overlapped I/O" ); } // Setup the overlapped structure ov.hEvent = hevtOverlapped; // Open the "STOP" handle hevtStop = ::CreateEvent(0,TRUE,FALSE,_T("Overlapped_Stop_Event")); if (hevtStop == 0) { //LOG( "Unable to create manual-reset event for stop event" ); } HandleOfThread = CreateThread( NULL, 0, ThreadHandler, 0, 0, NULL); } CPort::~CPort() { //fContinue = false; //CloseHandle( HandleOfThread ); //serial.Close(); } void CPort::Close() { fContinue = false; CloseHandle( HandleOfThread ); serial.Close(); } wchar_t *CPort::GetData() { return data; } bool CPort::getCTS() { return serial.GetCTS(); } bool CPort::getDSR() { return serial.GetDSR(); } bool CPort::getRing() { return serial.GetRing(); } Unreal Script Code: class MyPlayerController extends GamePlayerController DLLBind(SerialPortDLL); dllimport final function Open(string portName); dllimport final function Close(); dllimport final function string GetData();

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  • VirtualBox appliance for the Oracle Communications Service Delivery Platform (SDP) Products

    - by chlander
    It's been quite awhile since we last blogged. This blog is written by Leif Lourie, a Curriculum Developer for the Oracle Communications Service Delivery Platform (SDP) products. For the last 8 years, Leif has worked as a Curriculum Developer for many of the telecom-oriented products that Oracle offers. He has been working in the telecom industry for about 25 years and has also worked as a software developer, project manager, and solutions architect. He is currently working on courseware for an upcoming release for one of the Service Delivery Platform products. Thanks to Leif not only for this blog, but for making the VM described in the blog available. Cheryl Lander, Oracle Communications InfoDev Senior Director To be able to download, install and test a product within a day is many times very important for people that are doing the primary evaluation of a software product. If it takes longer, it will require a bigger effort, like a proof-of-concept project with many people involved. Of course, if the product is chosen for a more thorough test, it will probably happen anyway, but then maybe with focus on integration instead of product features. We have a long tradition of creating complex software that is easy to install and test and we have often been praised for the ease of getting our products up and running. One key for this has been that there has always been an installer for Windows, as well as for the production environments that usually are Unix and Linux. And, the windows installer has, in most cases, been released for developing and testing purposes. Lately, this has changed. Our products are very seldom released for the Windows platform, at all. And even the Linux versions are almost always released for 64-bit systems. This is creating problems for many of the people that want to try out our products, since few have access to a 64-bit Linux system of the right platform. Most of us are using a laptop with Windows or Mac OS. Some of us are using Linux or Solaris, but probably a non certified distribution for the product you want to test. My job, among other things, is to develop hands-on practices for our products. For me, it is crucial to have access to environments for installing and using our products. For this reason I have been using virtual machines for many years.I have a ready-made base system, with the necessary tools installed for all the products I create hands-on practices for. Whenever I start working on hands-on practices for a new product or a new version, I just copy the base system and start working with a clean slate. This saves me a lot of time! Now, I would like to start saving time for my favorite student: You! If you are using our products and regularly test new versions you might benefit from the virtual machine that is now available on Oracle Technology Network: The Virtual Machine for the Oracle Communications Service Delivery Platform (SDP) Products. This virtual machine contains an installation of the 64-bit version of Oracle Enterprise Linux, version 6. It also has Oracle Database Express Edition (XE), Oracle Java and Oracle Enterprise Pack for Eclipse installed. By using Oracle VM VirtualBox you may use Windows, OS X, Linux or Solaris on your laptop. VirtualBox can be installed on top of any of these platforms and give you the ability to run virtual machines in your laptop. After downloading and starting the virtual machine you will also need to download the installation files for the product you want to test; for example Oracle Communications Services Gatekeeper or Oracle Communications Online Mediation Controller. In some cases there are lessons and practices available for the products. The freely available courses are listed in Oracle Learning Library as a Collection of Oracle Communications Service Delivery Platform Courses. As time goes by, we will make this list collection bigger. Also, the goal is to update the virtual machine about one to two times per year. So you will always be able to get a well maintained virtual machine for the Service Delivery Platform products from us. We Value Your Feedback If you would like to suggest improvements or report issues on any of the product documentation, curriculum, or training produced by the Oracle Communications Information Development team, you can use these channels: Email [email protected]. Post a comment on this blog. Thanks for reading!

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  • Serial Port Data Structure

    - by Seth Archer
    I need to send data to a hardware device over serial port. I'm using a program called serial port tool for os x. After I connect to the device there is a form box where I can type data to send. I have no idea how to format the data. Here is an excerpt from the manual for the device. "The Net Manager Command structure consists of one start byte, one command byte, five bytes of data, and a one byte checksum. Each message packet is formatted as follows:" an example command is: Byte0=30 Byte1=7 Byte2=5 Byte3=1 Byte4=2 Byte5=0 Byte6=245 How do I type that into the form box in serial port tool? Thanks, Seth

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  • Serial Mac OS X constantly freezes/locks/dissappears for USB to Arduino

    - by Niraj D
    I have a problem with my C++ code running in Xcode with both the AMSerial library as well as the generic C (ioctl, termios). After a fresh restart, my application works well but after I "kill" the program the Serial (I think) is not released. I have checked my open files under /dev and have killed the connection to serial USB from there, but my C++ still can't open the USB port. I have narrowed this down to being a low level Mac OS X issue, regarding blocking the port indefinitely, regardless of closing it using the aforementioned libraries. Just for context, I'm trying to send numbers through my USB port, serially to an Arduino Duemilanove at 9600 baud. Running Serial Monitor in Arduino is perfectly fine, however, running through a C++ application it freezes up my computer, occasionally, my mouse/keyboard freeze up: requiring a hard reset. How can this problem be fixed? It seems like Mac OS X is not USB friendly!

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  • System.UnauthorizedAccessException from Serial Port in VB.NET

    - by psuhas
    I am using VB.NET 2008 Express Edition to access Serial Port which is a USB to Serial port. Since this is removable, the app user can disconnect it at any time in app. I am getting an unhandled exception when I remove the USB Serial Port. After research, it seems like a known problem in .NET (even in 3.5) I am looking for some solution to get this done. I have already tried the app.config solution that was suggested and it does not work Here is the link for issue http://connect.microsoft.com/VisualStudio/feedback/Validation.aspx?FeedbackID=140018

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  • timing of reads from serial port on windows

    - by Marcin K
    I'm trying to implement a protocol over serial port on a windows(xp) machine. The problem is that message synchronization in the protocol is done via a gap in the messages, i.e., x millisecond gap between sent bytes signifies a new message. Now, I don't know if it is even possible to accurately detect this gap. I'm using win32/serport.h api to read in one of the many threads of our server. Data from the serial port gets buffered, so if there is enough (and there will be enough) latency in our software, I will get multiple messages from the port buffer in one sequence of reads. Is there a way of reading from the serial port, so that I would detect gaps in when particular bytes were received?

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  • controling individual pins on a serial port

    - by Faken
    I know that serial ports work by sending a single stream of bits in serial. I can write programs to send and receive data from that one pin. However, there are a lot more other pins on the serial port connection that normal aren't used but from documentation all seem to have some sort of function for signalling as opposed to data transfer. Is it possible in any way to cause the other pins that are not used for direct data transfer to be controlled individual? If so, how would i go about doing that?

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  • VB6 Serial port programming

    - by commodus86
    I'm not much experienced in VB6 serial port programming. I need to control another circuit through serial port. (I have heard that pin 4 and pin 7 are used for that purpose. If these pins are incorrect please tell me what pins are used for such purposes) My requirement is to set those pins to high or low and read their levels(high or low) through VB6 program. How to do the task?? Thanx,

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  • grep 5 seconds of input from the serial port inside a shell-script

    - by pica
    I've got a device that I'm operating next to my PC and as it runs it's spitting log lines out it's serial port. I have this wired to my PC and I can see the log lines fine if I'm using either minicom or something like: ttylog -b 115200 -d /dev/ttyS0 I want to write 5 seconds of the device serial output to a temp file (or assign it to a variable) and then later grep that file for keywords that will let me know how the device is operating. I've already tried redirecting the output to a file while running the command in the background, and then sleeping 5 seconds and killing the process, but the log lines never get written to my temp file. Example: touch tempFile ttylog -b 115200 -d /dev/ttyS0 >> tempFile & serialPID=$! sleep 5 #kill ${serialPID} #does not work, gets wrong PID killall ttylog cat tempFile The file gets created but never filled with any data. I can also replace the ttylog line with: ttylog -b 115200 -d /dev/ttyS0 |tee -a tempFile & In neither case do I ever see any log lines logged to stdout or the log file unless I have multiple versions of ttylog running by mistake (see commented out line, D'oh). I have no idea what's going on here. It seems to be a failure of redirection within my script. Am I on the right track? Is there a better way to sample 5 seconds of the serial port?

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  • error detection/correction/recovery in serial protocols

    - by Jason S
    I have some designing to do for a serial protocol and am running into some questions that I figure must have been considered elsewhere. So I'm wondering if there are some recommendations for best practices in designing serial protocols. (Please either state a fact that is easily verifiable, or cite a reputable source if you make a claim.) General recommendations for websites/books are also welcome. In particular I have to deal with issues like parsing a stream of bytes into packets verifying a packet is correct (easy with a CRC, for instance) identifying reasonable types of errors that can occur (e.g. in a point-to-point serial stream, sporadic single bit errors, and dropped series of bytes, are both likely, but extra phantom bytes are unlikely; whereas with a record stored in flash memory or on a disk drive the types of errors that predominate are different) error correction or recovery (if I detect an error in a packet, can I correct it? If not, can I resync to the boundary of the next packet?) how to make variable-length packets robust to error correction / recovery. Any suggestions?

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  • Podcast: Oracle Introduces Oracle Communications Data Model

    - by kimberly.billings
    I recently sat down with Tony Velcich from Oracle's Communications Product Management team to learn more about the new Oracle Communications Data Model (OCDM). OCDM is a standards-based data model for Oracle Database that helps communications service providers jumpstart data warehouse and business intelligence initiatives to realize a fast return on investment by reducing implementation time and costs. Listen to the podcast. var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); try { var pageTracker = _gat._getTracker("UA-13185312-1"); pageTracker._trackPageview(); } catch(err) {}

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  • Communications: Customer Experience

    - by Michael Seback
    What might a new customer experience look like in Communications? Could a customer research comments from social networks, buy online and be geo directed to a nearby store to pick up the device?  Could the customer be contacted proactively that he is approaching a data threshold for a smart phone and be offered value added options to manage usage? Could the customer upgrade video features interactively and leverage loyalty points for payment? Watch this short Communications Customer Experience story to see a scenario that addresses these challenges and many more.   Learn about the Oracle Customer Experience and Oracle Communications.

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  • Serial port : Read data problem, not reading complete data

    - by Anuj Mehta
    Hi I have an application where I am sending data via serial port from PC1 (Java App) and reading that data in PC2 (C++ App). The problem that I am facing is that my PC2 (C++ App) is not able to read complete data sent by PC1 i.e. from my PC1 I am sending 190 bytes but PC2 is able to read close to 140 bytes though I am trying to read in a loop. Below is code snippet of my C++ App Open the connection to serial port serialfd = open( serialPortName.c_str(), O_RDWR | O_NOCTTY | O_NDELAY); if (serialfd == -1) { /* * Could not open the port. */ TRACE << "Unable to open port: " << serialPortName << endl; } else { TRACE << "Connected to serial port: " << serialPortName << endl; fcntl(serialfd, F_SETFL, 0); } Configure the Serial Port parameters struct termios options; /* * Get the current options for the port... */ tcgetattr(serialfd, &options); /* * Set the baud rates to 9600... */ cfsetispeed(&options, B38400); cfsetospeed(&options, B38400); /* * 8N1 * Data bits - 8 * Parity - None * Stop bits - 1 */ options.c_cflag &= ~PARENB; options.c_cflag &= ~CSTOPB; options.c_cflag &= ~CSIZE; options.c_cflag |= CS8; /* * Enable hardware flow control */ options.c_cflag |= CRTSCTS; /* * Enable the receiver and set local mode... */ options.c_cflag |= (CLOCAL | CREAD); // Flush the earlier data tcflush(serialfd, TCIFLUSH); /* * Set the new options for the port... */ tcsetattr(serialfd, TCSANOW, &options); Now I am reading data const int MAXDATASIZE = 512; std::vector<char> m_vRequestBuf; char buffer[MAXDATASIZE]; int totalBytes = 0; fcntl(serialfd, F_SETFL, FNDELAY); while(1) { bytesRead = read(serialfd, &buffer, MAXDATASIZE); if(bytesRead == -1) { //Sleep for some time and read again usleep(900000); } else { totalBytes += bytesRead; //Add data read to vector for(int i =0; i < bytesRead; i++) { m_vRequestBuf.push_back(buffer[i]); } int newBytesRead = 0; //Now keep trying to read more data while(newBytesRead != -1) { //clear contents of buffer memset((void*)&buffer, 0, sizeof(char) * MAXDATASIZE); newBytesRead = read(serialfd, &buffer, MAXDATASIZE); totalBytes += newBytesRead; for(int j = 0; j < newBytesRead; j++) { m_vRequestBuf.push_back(buffer[j]); } }//inner while break; } //while

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  • Issues writing to serial port on MAC OSX using unistd.h in c

    - by Schuyler
    I am trying to write to a bluetooth device on MAC OSX using the unistd.h Linux functions in c. I am connecting fine and writing the first few bytes with success. When I try to write other commands to it (there are bytes added to the write buffer every 15ms), I don't see any results even though the write() function returns 1 (write success). If you start a write and it doesn't finish by the time you try to start another write (since it is non-blocking), could that possibly screw up the initial write? (If so, is there any way to check if a write has completed?) That is the only thing I can think of since the writes are occurring fairly frequently and the first two are successfully sent. qwbyte() simply adds a byte to the output array and increments its length The open port function: BAMid = -1; struct termios options; struct termios originalTTYAttrs; // Open the serial port read/write, nonblocking, with no controlling terminal, and don't wait for a connection. BAMid = open(strPath, O_RDWR | O_NOCTTY | O_NONBLOCK); if (BAMid == -1) { printf("Error opening serial port %s - %s(%d).\n", strPath, strerror(errno), errno); goto error; } // Issue TIOCEXCL ioctl to prevent additional opens except by root-owned processes. if (ioctl(BAMid, TIOCEXCL) == -1) { printf("Error setting TIOCEXCL on %s - %s(%d).\n", strPath, strerror(errno), errno); goto error; } // Get the current options and save them so we can restore the default settings later. if (tcgetattr(BAMid, &originalTTYAttrs) == -1) { printf("Error getting tty attributes %s - %s(%d).\n", strPath, strerror(errno), errno); goto error; } // The serial port attributes such as timeouts and baud rate are set by modifying the termios // structure and then calling tcsetattr() to cause the changes to take effect. Note that the // changes will not become effective without the tcsetattr() call. options = originalTTYAttrs; // Set raw input (non-canonical) mode, with reads blocking until either a single character // has been received or a one second timeout expires. [should be moot since we are leaving it as nonblocking] cfmakeraw(&options); options.c_cc[VMIN] = 1; options.c_cc[VTIME] = 10; cfsetspeed(&options, B57600); // Set 57600 baud options.c_cflag |= CS8; // Use 8 bit words // Cause the new options to take effect immediately. if (tcsetattr(BAMid, TCSANOW, &options) == -1) { printf("Error setting tty attributes %s - %s(%d).\n", strPath, strerror(errno), errno); goto error; } //flush old transmissions if (tcflush(BAMid,TCIOFLUSH) == -1) { printf("Error flushing BAM serial port - %s(%d).\n", strerror(errno), errno); } oBufLength = 0; // Ask it to start if (! qwbyte(CmdStart) ) { goto error; } if (! qwbyte(CmdFull) ) { goto error; } //this transmit works txbytes(); printf("success opening port!"); return -1; // Failure path error: if (BAMid != -1) { close(BAMid); } printf("returning an error--%d",errno); return errno; } The write function (txbytes): int i, bufSize, numBytes; if(oBufLength != 0) { //if the output array isn't empty //duplicating the output array and its size so it can //be overwritten while this write is occuring printf("about to transmit: "); for(i = 0; i < oBufLength; i++) { printf(" %u",oBuf[i]); tempBuf[i] = oBuf[i]; } printf("\n"); bufSize = oBufLength; oBufLength = 0; numBytes = write(BAMid, &tempBuf, bufSize); printf("bytes written = %d\n",numBytes); if (numBytes == -1) { printf("Error writing to port - %s(%d).\n", strerror(errno), errno); } return (numBytes 0); } else { return 0; }

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  • Linux - serial port read returning EAGAIN...

    - by Andre
    Hello all! I am having some trouble reading some data from a serial port I opened the following way. I've used this instance of code plenty of times and all worked fine, but now, for some reason that I cant figure out, I am completely unable to read anything from the serial port. I am able to write and all is correctly received on the other end, but the replies (which are correctly sent) are never received (No, the cables are all ok ;) ) The code I used to open the serial port is the following: fd = open("/dev/ttyUSB0", O_RDWR | O_NONBLOCK | O_NOCTTY); if (fd == -1) { Aviso("Unable to open port"); return (fd); } else { //Get the current options for the port... bzero(&options, sizeof(options)); /* clear struct for new port settings */ tcgetattr(fd, &options); /*-- Set baud rate -------------------------------------------------------*/ if (cfsetispeed(&options, SerialBaudInterp(BaudRate))==-1) perror("On cfsetispeed:"); if (cfsetospeed(&options, SerialBaudInterp(BaudRate))==-1) perror("On cfsetospeed:"); //Enable the receiver and set local mode... options.c_cflag |= (CLOCAL | CREAD); options.c_cflag &= ~PARENB; /* Parity disabled */ options.c_cflag &= ~CSTOPB; options.c_cflag &= ~CSIZE; /* Mask the character size bits */ options.c_cflag |= SerialDataBitsInterp(8); /* CS8 - Selects 8 data bits */ options.c_cflag &= ~CRTSCTS; // disable hardware flow control options.c_iflag &= ~(IXON | IXOFF | IXANY); // disable XON XOFF (for transmit and receive) options.c_cflag |= CRTSCTS; /* enable hardware flow control */ options.c_cc[VMIN] = 0; //min carachters to be read options.c_cc[VTIME] = 0; //Time to wait for data (tenths of seconds) //Set the new options for the port... tcflush(fd, TCIFLUSH); if (tcsetattr(fd, TCSANOW, &options)==-1) { perror("On tcsetattr:"); } PortOpen[ComPort] = fd; } return PortOpen[ComPort]; After the port is initializeed I write some stuff to it through simple write command... int nc = write(hCom, txchar, n); where hCom is the file descriptor (and it's ok), and (as I said) this works. But... when I do a read afterwards, I get a "Resource Temporarily Unavailable" error from errno. I tested select to see when the file descriptor had something t read... but it always times out! I read data like this: ret = read(hCom, rxchar, n); and I always get an EAGAIN and I have no idea why. All help would be appreciated. Cheers

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  • threaded serial port IOException when writing

    - by John McDonald
    Hi, I'm trying to write a small application that simply reads data from a socket, extracts some information (two integers) from the data and sends the extracted information off on a serial port. The idea is that it should start and just keep going. In short, it works, but not for long. After a consistently short period I start to receive IOExceptions and socket receive buffer is swamped. The thread framework has been taken from the MSDN serial port example. The delay in send(), readThread.Join(), is an effort to delay read() in order to allow serial port interrupt processing a chance to occur, but I think I've misinterpreted the join function. I either need to sync the processes more effectively or throw some data away as it comes in off the socket, which would be fine. The integer data is controlling a pan tilt unit and I'm sure four times a second would be acceptable, but not sure on how to best acheive either, any ideas would be greatly appreciated, cheers. using System; using System.Collections.Generic; using System.Text; using System.IO.Ports; using System.Threading; using System.Net; using System.Net.Sockets; using System.IO; namespace ConsoleApplication1 { class Program { static bool _continue; static SerialPort _serialPort; static Thread readThread; static Thread sendThread; static String sendString; static Socket s; static int byteCount; static Byte[] bytesReceived; // synchronise send and receive threads static bool dataReceived; const int FIONREAD = 0x4004667F; static void Main(string[] args) { dataReceived = false; readThread = new Thread(Read); sendThread = new Thread(Send); bytesReceived = new Byte[16384]; // Create a new SerialPort object with default settings. _serialPort = new SerialPort("COM4", 38400, Parity.None, 8, StopBits.One); // Set the read/write timeouts _serialPort.WriteTimeout = 500; _serialPort.Open(); string moveMode = "CV "; _serialPort.WriteLine(moveMode); s = null; IPHostEntry hostEntry = Dns.GetHostEntry("localhost"); foreach (IPAddress address in hostEntry.AddressList) { IPEndPoint ipe = new IPEndPoint(address, 10001); Socket tempSocket = new Socket(ipe.AddressFamily, SocketType.Stream, ProtocolType.Tcp); tempSocket.Connect(ipe); if (tempSocket.Connected) { s = tempSocket; s.ReceiveBufferSize = 16384; break; } else { continue; } } readThread.Start(); sendThread.Start(); while (_continue) { Thread.Sleep(10); ;// Console.WriteLine("main..."); } readThread.Join(); _serialPort.Close(); s.Close(); } public static void Read() { while (_continue) { try { //Console.WriteLine("Read"); if (!dataReceived) { byte[] outValue = BitConverter.GetBytes(0); // Check how many bytes have been received. s.IOControl(FIONREAD, null, outValue); uint bytesAvailable = BitConverter.ToUInt32(outValue, 0); if (bytesAvailable > 0) { Console.WriteLine("Read thread..." + bytesAvailable); byteCount = s.Receive(bytesReceived); string str = Encoding.ASCII.GetString(bytesReceived); //str = Encoding::UTF8->GetString( bytesReceived ); string[] split = str.Split(new Char[] { '\t', '\r', '\n' }); string filteredX = (split.GetValue(7)).ToString(); string filteredY = (split.GetValue(8)).ToString(); string[] AzSplit = filteredX.Split(new Char[] { '.' }); filteredX = (AzSplit.GetValue(0)).ToString(); string[] ElSplit = filteredY.Split(new Char[] { '.' }); filteredY = (ElSplit.GetValue(0)).ToString(); // scale values int x = (int)(Convert.ToInt32(filteredX) * 1.9); string scaledAz = x.ToString(); int y = (int)(Convert.ToInt32(filteredY) * 1.9); string scaledEl = y.ToString(); String moveAz = "PS" + scaledAz + " "; String moveEl = "TS" + scaledEl + " "; sendString = moveAz + moveEl; dataReceived = true; } } } catch (TimeoutException) {Console.WriteLine("timeout exception");} catch (NullReferenceException) {Console.WriteLine("Read NULL reference exception");} } } public static void Send() { while (_continue) { try { if (dataReceived) { // sleep Read() thread to allow serial port interrupt processing readThread.Join(100); // send command to PTU dataReceived = false; Console.WriteLine(sendString); _serialPort.WriteLine(sendString); } } catch (TimeoutException) { Console.WriteLine("Timeout exception"); } catch (IOException) { Console.WriteLine("IOException exception"); } catch (NullReferenceException) { Console.WriteLine("Send NULL reference exception"); } } } } }

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  • weird characters displayed during serial communication OSX

    - by nemo
    I have tried communicating via serial (OSX w/ prolific drivers - USB RS232 adapter - Tx,Rx and GND pins on device serial ttl port) to a device and done so successfully using screen /dev/tty.usbserial 115200 8N1 I get to log in and use it as if I was SSH or TelNetted in... However whenever I try to go into system recovery mode (holding CTRL+1) while the device is powering on, it starts displaying weird characters and until I close the screen session it will continue showing weird characters: Of course when we tried doing the same thing on my boss' macbook running windows and PuTTY and everything worked fine, even in system recovery mode; characters were displayed properly. What gives? Id like to learn the intuition to use because up till now I concluded that since I can bot into the system and see characters normally everything about the connection should be fine and its must have been the recovery partition that was broken. This was wrong of course... Niko

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  • Reading Binary data from a Serial Port.

    - by rross
    I previously have been reading NMEA data from a GPS via a serial port using C#. Now I'm doing something similar, but instead of GPS from a serial. I'm attempting to read a KISS Statement from a TNC. I'm using this event handler. comport.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived); Here is port_DataReceived. private void port_DataReceived(object sender, SerialDataReceivedEventArgs e) { string data = comport.ReadExisting(); sBuffer = data; try { this.Invoke(new EventHandler(delegate { ProcessBuffer(sBuffer); })); } catch { } } The problem I'm having is that the method is being called several times per statement. So the ProcessBuffer method is being called with only a partial statment. How can I read the whole statement?

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