Networking :: Serial Port : Not Able To Write Big Chunk Of Data?
Mar 10, 2010
I am trying to send text data from one PC to other using Serial cable. One of the PC is running linux and I am sending data from it using write(2) system call. The log size is approx 65K bytes but the write(2) system call returns some 4K bytes (i.e. this much amount of data is getting transferred). I tried breaking the data in chunks of 4K but write(2) returns -1.My question is that "Is there any buffer limit for writing data on serial port? or can I send data of any size?. Also do I need to continously read data from other PC as I write 4K chunk of data"Do I need to do any special configuration in termios structure for sending (huge) data?
trying read serial COM port and want to write that received data to file, now its writing only one sentence, but i want to write full file which coming on serial port, as i'm sending file from hyper terminal and reading on linux pc, If i put while loop its not writing anything,without while loop its writing only one line and if send big file then application terminates and then writes to file.But i need do write any size which coming on serial port.Finally i want write full file which is coming on hyper terminal, after writing the file it has wait for next data. This is my code,
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++ AppOpen the connection to serial port
I am using read() in c++ to get data from a serial port. However, if no data is available on the serial port the function blocks until dta arrives.Example code:
I need to read and write to a serial device. When I connect via gtkterm, I need to toggle DTR before I can communicate with the device . My problem is that I cannot emulate this in C++.
I want to write some code that can setup a comport, toggle the DTR, then read and write strings to the port. However all my attempts have been fruitless. My serial settings are B9600, No parity, no hardware control, 8 bt characters and 1 stop bit:
I have a minilinux that I being working on, the problem now is that the serial ports doesn't seem to work (I have 4 serial ports).They don't write or read.
I run the command setserial g /dev/ttySx and it says that his IRQ are 3 or 4 (3 for ttyS0 and ttyS2 , 4 for ttyS1 and ttyS4)�but when I run the command: dmesg | grep ttyS the IRQ�s are 0 for ALL my serial ports� could be this the reason why my serial ports aren�t working right??? And if it is how can I solve the problem??
I'm currently developping a C program to drive a Telit GM862-GPS module using the serial port of an embedded board (SBC9261).The communication with the module is based on AT commands : I just send my command to the module, through the RS232 line, and the module answers immediately.Here's an example with a basic command returning the GPS's acquired position, sent with Minicom :
I dont know if this is the right forum, But I try to find a solution, I want to intercept data from/to serial port without disrupting the software that manages the serial port, (I would like to save the data to a file or sent into a socket) I searched somes modules and programs (linspy, ttysniff, interceptty, maxty ...), A bit complicated (There are some diff. between kernel 2.4 and 2.6), So I'd like to change the serial port driver to intercept the "read" and "write " and do what I want with the data, I'd like to know what do you think about
I am not a profession programmer. I have to write a C code which send some command to attach display using C program. Can any one please help me in this regard.
I have got a problem while reading from the serial port. I'm working on iMX-31 board and Eclipse IDE. Whenever I'm trying to read any data through the serial port, it's displaying I/O Possible and the application is being terminated. After reading I'm trying to write this data on a file. Here are the excerpts from the code:
I have connected a device to my linux system with a serial cable (rs232). The settings are: port /dev/ttyS0, baud rate=38400, data bits=8, stop bits=1, no parity, no hardware or software handshaking. I wrote a linux program that sends 1 byte to the device, but the device doesn't receive it. I know the serial ports are working because when I use the CuteCOM application to send data, the device DOES receive it, so obviously it is a problem with my code..
i want to try with a small application in linu in that i want to read some data from controller using serial port and i wanna transfor that data to another meachin in the network for this i want serial port interfacing programming as well as socket programming.
I am doing work on serial port. I want to send/receive data to/from Microcontrolar through serial port. But I don't know how to initialize, receive and send data to Serial port. i am new in fedora so i hav'nt any deep concept of fedora.can anyone send me C code , which communicate through serial port in fedora (or atleast help me). I am using Fedora 11.
I am writing a C program which reads data over serial port. While reading data, if I send my data(which is a 13 byte structure) periodic with a period of 1 second for 10 times I read it without problem and I read the data 10 times as I sent and as I expectBut if I send data continuousuly(without any time interval between each sending) 10 times I can only read 1 of them(I can only read it once).
I am implementing a simple serial protocol where my ARM9 board, running Linux is communicating to a slave peripheral board. The Master sends a 12 byte data stream and the peripheral board returns status in a 23 byte response. The serial port is opened in raw mode. It works perfectly on 44 reads; however, on the 45 read the data returned from the read() is incorrect. I've framed what's being sent on an oscope and it is correct.The coincidence is that 23 x 44 = 1012. It's as though the receive buffer is 1K and when I go past the boundary I get bad data. The read following the bad one is good again.I've tried flushing the buffer before reading but get the same result.Here's the port initialization code:
I am trying to get two way serial communications going between a Windows XP system and a Linux system (RHEL 5).I have /sbin/agetty -L 9600 ttyS0
in /etc/inittab. I am using a generic USB to serial adaptor on Windows (Unitek) and a null modem cable. I have putty configured for 9600 baud, 8 bits, no parity, one stop bit, no flow control.I get the login prompt from agetty in the putty window but input does not work; I see weird characters in the putty screen. I can echo output into the device from windows and see it, but
cat < /dev/ttyS0. just prints out weird characters from what I type.
I want to implement the following scenario :-[workstation1] <--ETHERNET-->[device 1]<--SERIAL-->[device 2]<--ETHERNET-->[workstation2]In short, a LAN over Serial link (RS-232 for instance).If there is a utility that offers such functionality, kindly give me the name, i've googled a bit, and found ser2net, but that only works with TELNETing.. i want it work like a normal LAN like file-sharing n all but over Serial.If there is no such software, then obv i have to program myself. regarding which i have more questions
I would like to be able to ssh to a TCP port on my server and be directly connected to the serial port @ 115200 Null modem config. Does any body know how one can do this?
We have a new machine with RedHat enterprise 5 on it. I need to connect a serial cable to the serial port and talk to another system (old alpha system) instead of using a VT connected to the alpha.Does RedHat come with anything like Keaterm/hyperterm/etc etc?
Hello. I want to use my Debian box as an internet connection for a Win95 laptop. The laptop is old enough that the only port I have available to connect to the internet from is the serial port. I have heard that a serial port redirector will allow it to access the internet through my debian box, but I have no clue how to set one up. Any advice. Thanks
I am new to linux terminal programming and all but i want to set up a simple serial communication from my desktop through USB port. The actual idea to to write some data in the terminal and build a terminal program that sends the data to the usb port with a fixed baud rate. are there ready made terminal programs available for this simple communication?or atleast any Graphical tools which could help me build and design such a terminal in ubuntu 9.04?
I'm trying to set rxtxSerial to work so a Java app has access to a serial port (via SiLabs CP210x driver, port /dev/ttyUSB0). When I use update-alternatives --config java, there are 3 alternatives which provide `java'. I have tried openJDK and Sun. Both fail but with completely different messages.
Is possible to detect port scanning just by using utilities included in linux (netstat, iptables...), Yes there is utility called psad but I would write some scripts for my own and learn something new
I am not a C++ geeg, so first thing that comes to my mind is that i will use simple BASH SCRIPT that will interact with iptables and monitor user activity, network activity etc. (but I thing that would not be good solution due to performance and capabilities, and also I am not familliar with memory in linux at all). I was reading aboud SNORT HIDS, NIDS... AFAIK some information can be obtainet from /proc but I have no idea which values should be monitored.
I am writing some application in C, which will access a serial port device (RS232). My application is working good. But if any other application is already opened the port, I couldn't able to identify that. In windows VB program, while accessing comport through mscomm control, i am receiving an error as "Port Already Opened". But in Linux environment, through C program how can i get that? I am accessing comport 1 as follows
I'm working on testing some software, and I have a question. We have several files of binary data that we need to push through our application to test. It communicates via simple TCP sockets. Is there a way I can send this data to the socket from the command line? I tried doing something like this, but telnet never picked up the data.
About 7 years ago I setup a Redhat system with 8 serial terminals and 8 serial printers, this is still running but I need to get another system running so the original can be taken down for maintenance. The printers are ancient Newbury data dot matrix wide carriage with 7 data bits receive 8 data bits transmit Xon/Xoff flow control. Now I remember setting the transmit and receive data bits as above but after 7 years can't remember where.
Can anyone one give me some pointers please, for talking to a serial port, if I use cutecom it always returns "could not open /dev /tty0 or 1 or 3 or 4, even tried ttys0 etc
