Windows Serial Port Maximum Baud Rate

Under "Bits per second" lists values you can enter in the proprieties field for your com port. If you want higher than what your hardware allows you need other hardware or use something other than a serial port to transfer between the two devices.

windows serial port maximum baud rate

1st, the serial port hardware needs to support the datarate. 2nd, the driver needs to let you choose the desired baudrate. Some drivers or chips may require tweaking to let you select non-standard (or higher than 115200) baudrates. The max baudrate of a few USB to serial chips I've come across:

Is there a particular reason you're choosing to use a serial port? While still used, it's widely deprecated in favor of more modern approaches. If you're transferring between processes on one machine, a named pipe or just using the filesystem might be better. If you're transferring between two computers, consider using TCP/IP networking.

The following example demonstrates the use of the SerialPort class to allow two users to chat from two separate computers connected by a null modem cable. In this example, the users are prompted for the port settings and a username before chatting. This code example is part of a larger code example provided for the SerialPort class.

I want to send and receive data at 230Kbps or higher. Is there any limitation on the serial port / SW on higher baudrates ? I am sending the data from microcontroller. I see lot of blogs which mention that 115.2kbps is maximum on serial port. Is it correct ?

As far as I know, It also depends of the USART installed on your motherboard.Normally 230.4 kbps is the maximum speed supported, but older PCs may have a lower maximum limit.Check all above, if possible.

you have good answer from Kristin. Simply all depends for first to your HW, try find relevant infos what is your HW COM port speed limit. Simply you can also use external USB-serial adapter with other characteristic. Other hint can be then look to .NET library about SerialPort what type is Speed defined. Via this info you can also know what maximum value you can set, but of course with your true HW option.

What is the maximum baud rate for serial communications? I need to send a lot of data at a high speed over USB. I'm going to use the built in USB or FTDI serial to USB converter chips. I did some experimenting and it seems like the maximum baud rate that the mBed supports is 115200 (v24 of library).

OK, I see an example using 921600 baud. I tried that and it works. However, many baud rates between 115200 and 921600 don't work. So, I;d like to revise my question to..... What are all of the valid baud rates for Serial?

Hmmm, I did an update to the libraries in May ( ) which is supposed to support the non-standard baud rates. Could you tell me which baud rates you have tried, which are not working? I know it handled the 1,000,000 baud rate the stepper motors used in the Etch-a-Sketch demo.

I will talk to our resident expert, and try and get a definitive list of supported baud rates. I believe that 921600 is the fastest it will go, however, and some people have had difficulties at that speed.

XM: Historic starting near teletype age. 110baud is very early modems, rest came as multiples of 300baud later. I've seen 150 but not 200. No reason can't have 200, someone would just need to modify the code with that definition, but if you check things like Win8 Com Port settings you won't see 200 as it isn't a standard. While most MCU these days allow setting any baud rate, many UART chips had a register for selecting only specific baud rates.

Jivitesh: Hope you resolved this. Define problems: no connect, no data, totally garbage data, occasional errors...Some possibilities: too much frequency error on those other baud rates causing glitches (May Depend on CPU crystal divisible frequencies), does your MCU divide the clock before sending to UART module thus reducing resolution/options, what UART baud rates are supported in your hardware?

FYI: Max baud rate for UART depends on frequency error between crystals and chosen baud rates at both ends. If the MCU crystal at either end isn't an exact multiple of the selected baud rate then some baudrates will have more error than others and just fail, that's just math. Check: CrystalFrequency/baudrate give an integer that MCU can program as a divider, or is there a significant remainder? Do for both ends. If you have an oscilloscope then measure the actual baudrate transmitted by either end to compare your requested baudrate versus actual. To be compatible with other people's hardware don't push it.

The max baud rate of the most serial ports and usb to serial ports is 115200.230400, 460800 and 921600 is not availlable at the most usb to serial ports.Older serial ports goes up to 57600 baud

But for long cables the max baud rates is lower.Then it depends on the voltage level. Valid signals detected > +3V and The common voltage is +15V and -15V but some serial ports are only driven by +-8V or some driven at +-5VSo you must check the cable length, cable quality and the voltage level to define the max baud rate.

After running F2807x "usb_dev_serial" example codes and installing driver in controlSUITE, as below picture, the maximum baud rate of virtual serial port is 128000, would you please kindly suggest how to increase it to 921600 or above (eg. 1843200)? Thanks!

You do need a terminal which can open COM port at custom baudrate. The list of available baudrates shown on your screenshots is not written in stone. You can open a COM port on FTDI at any baudrate, but the FDTI will open it at the closes frequency it can.

I have an Arduino Pro 5V 16MHz with an USB2serial light adapter connected to my PC using Windows 7. There is an WS2812B Adalight sketch running on the Arduino which works just fine.The problem is that the highest baud rate that is working for me is 230400 baud. Baud rates above that (i tried 250000, 256000, 500000), though theoretically possible with the ATmega328P, simply do not work at all. What could the problem? I could post my sketch code if need be...

I have got my Uno to work at 500,000 and 1,000,000 baud so I don't know why your device won't work. Are you sure the limitation is not at the other end. Remember the baud rate is set by the PC the device is connected to.

Robin2:I have got my Uno to work at 500,000 and 1,000,000 baud so I don't know why your device won't work. Are you sure the limitation is not at the other end. Remember the baud rate is set by the PC the device is connected to.

In computing, a serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time.[1] This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. Throughout most of the history of personal computers, data has been transferred through serial ports to devices such as modems, terminals, various peripherals, and directly between computers.

While interfaces such as Ethernet, FireWire, and USB also send data as a serial stream, the term serial port usually denotes hardware compliant with RS-232 or a related standard, such as RS-485 or RS-422.

Modern consumer personal computers (PCs) have largely replaced serial ports with higher-speed standards, primarily USB. However, serial ports are still frequently used in applications demanding simple, low-speed interfaces, such as industrial automation systems, scientific instruments, point of sale systems and some industrial and consumer products.

Server computers may use a serial port as a control console for diagnostics, while networking hardware (such as routers and switches) commonly use serial console ports for configuration, diagnostics, and emergency maintenance access. To interface with these and other devices, USB-to-serial converters can quickly and easily add a serial port to a modern PC.

Modern devices use an integrated circuit called a UART to implement a serial port. This IC converts characters to and from asynchronous serial form, implementing the timing and framing of data specified by the serial protocol in hardware. The IBM PC implements its serial ports, when present, with one or more UARTs.

Very low-cost systems, such as some early home computers, would instead use the CPU to send the data through an output pin, using the bit banging technique. These early home computers often had proprietary serial ports with pinouts and voltage levels incompatible with RS-232.

Before large-scale integration (LSI) made UARTs common, serial ports were commonly used in mainframes and minicomputers, which would have multiple small-scale integrated circuits to implement shift registers, logic gates, counters, and all the other logic needed. As PCs evolved serial ports were included in the Super I/O chip and then in the chipset.

The individual signals on a serial port are unidirectional and when connecting two devices, the outputs of one device must be connected to the inputs of the other. Devices are divided into two categories: data terminal equipment (DTE) and data circuit-terminating equipment (DCE). A line that is an output on a DTE device is an input on a DCE device and vice versa, so a DCE device can be connected to a DTE device with a straight wired cable, in which each pin on one end goes to the same numbered pin on the other end.