Net Serial Port Overrun Error
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Libraries Question 0 Sign in to vote I am writing a Windows Forms application (Visual C++ 2005) to record data from a device via RS485. The connection runs at a baud rate of 2000000 with 8 data bits, c# serial port example 1 stop bit, and parity set to none. No handshaking is used. Each data message is 720 .net serial port library bytes long, and messages are transmitted at 200Hz. The ReadBufferSize is 4096, the ReadTimeout is -1, and the ReceivedBytesThreshold is 1.My problem is
C# Serial Port Readasync
that I get frequent overrun errors. This has the effect of dropping the end of some of the messages (around 5% of them). What causes overrun errors? BytesToRead never comes close to ReadBufferSize, so I don't see
C# Serial Port Asynchronous Read
where it has received too many bytes. System::Void Recorder_Form::Serial_Port_DataReceived(System::Object^ sender, System::IO::Ports::SerialDataReceivedEventArgs^ e){ unsigned int count = 0; try { count = this->TM_Serial_Port->Read(this->In_Buffer,0,this->TM_Serial_Port->BytesToRead); } catch(...) {} try { this->Out_Writer->Write(this->In_Buffer,0,count); } catch(...) {}}In_Buffer is an array
peripheral devices, I use serial data streams a lot. Mostly USB virtual serial posts from FTDI, but also the USB Communication Device Class and real 16550-compatible UARTs on the PCI
Ben Voigt Serial Port
bus. Since looking at data through an in-circuit emulator debug interface is generally c# serial port datareceived a miserable experience, getting serial data communication with a custom PC application is essential to analyzing data quality and providing feedback c# serial port alternative on hardware designs. C# and the .NET Framework provide a rapid application development that is ideal for early development that needs to track changing requirements as hardware designs evolve. Ideal in most respects, https://social.msdn.microsoft.com/Forums/vstudio/en-US/da50167c-cee5-440a-b4e1-5dcae3392ca5/serialport-overrun-errors?forum=netfxbcl I should say. The System.IO.Ports.SerialPort class which ships with .NET is a glaring exception. To put it mildly, it was designed by computer scientists operating far outside their area of core competence. They neither understood the characteristics of serial communication, nor common use cases, and it shows. Nor could it have been tested in any real world scenario prior to shipping, without finding flaws that litter both http://www.sparxeng.com/blog/software/must-use-net-system-io-ports-serialport the documented interface and the undocumented behavior and make reliable communication using System.IO.Ports.SerialPort (henceforth IOPSP) a real nightmare. (Plenty of evidence on StackOverflow attests to this, from devices that work in Hyperterminal but not .NET because IOPSP makes setting certain parameters mandatory, although they aren’t applicable to virtual ports, and closes the port on failure. There’s no way to bypass or ignore failure of these settings during IOPSP initialization.) What’s even more astonishing is that this level of failure occurred when the underlying kernel32.dll APIs are immensely better (I’ve used the WinAPI before working with .NET, and still do when I want to use a function that .NET doesn’t have a wrapper for, which notably includes device enumeration). The .NET engineers not only failed to devise a reasonable interface, they chose to disregard the WinAPI design which was very mature, nor did they learn from two decades of kernel team experience with serial ports. A future series of posts will present the design and implementation of a rational serial port interface built upon, and preserving the style of, the WinAPI serial port functions. It fits seamlessly into the .NET event dispatch model, and multiple coworkers have expressed that it’s
Федерация 中国 (China) 日本 (Japan) 대한민국 (Korea) 台灣 (Taiwan) See All Countries Toggle navigation INNOVATIONS SHOP SUPPORT COMMUNITY United States Serial http://www.ni.com/white-paper/4052/en/ Communications Hardware Concepts and Hardware Overrun Errors Publish Date: Feb 15, 2007 | 81 Ratings | 3.51 out of 5 | Print Overview You can use serial communication to transmit data between computers, instruments, etc. While serial is a commonly used protocol, other types include USB, parallel port, etc. For information about flow serial port control and basic serial terminology, see the Serial Communication General Concepts link below. Table of Contents A Brief Overview of the Serial Communications Process Universal Asynchronous Receiver Transmitter (UART) Hardware Overrun Errors Troubleshooting Steps to Prevent Hardware Overrun Errors National Instruments Serial Interfaces 1. A Brief Overview of the Serial Communications Process c# serial port Computer serial ports transmit and receive data bit by bit. During transmission, the serial device driver program on the computer CPU takes each byte from the main computer memory (typically 8 KB in size) and places it onto the data bus along with the serial port I/O address. The byte then travels through the data bus and is stored in the serial port hardware buffer. When the serial port is ready to transmit data, it fetches the data from this hardware buffer, places it in its shift register, and transmits each bit over the communication line. The following figure shows this process: The shift register is one byte long. From the shift register, the serial port transmits data bit by bit. When the last bit in the shift register is transmitted, the serial port must request the next byte from the CPU via an interrupt request (IRQ). However, the CPU is usuall