src/PhpSerial.php
public function confBaudRate($rate)
    {
        if ($this->_dState !== SERIAL_DEVICE_SET) {
            trigger_error("Unable to set the baud rate : the device is " .
                          "either not set or opened", E_USER_WARNING);

            return false;
        }

        $validBauds = array (
            110    => 11,
            150    => 15,
            300    => 30,
            600    => 60,
            1200   => 12,
            2400   => 24,
            4800   => 48,
            9600   => 96,
            19200  => 19,
            38400  => 38400,
            57600  => 57600,
            115200 => 115200
        );

        if (isset($validBauds[$rate])) {
            if ($this->_os === "linux") {
                $ret = $this->_exec(
                    "stty -F " . $this->_device . " " . (int) $rate,
                    $out
                );
            } elseif ($this->_os === "osx") {
                $ret = $this->_exec(
                    "stty -f " . $this->_device . " " . (int) $rate,
                    $out
                );
            } elseif ($this->_os === "windows") {
                $ret = $this->_exec(
                    "mode " . $this->_winDevice . " BAUD=" . $validBauds[$rate],
                    $out
                );
            } else {
                return false;
            }

            if ($ret !== 0) {
                trigger_error(
                    "Unable to set baud rate: " . $out[1],
                    E_USER_WARNING
                );

                return false;
            }

            return true;
        } else {
            return false;
        }
    }
public function confBaudRate($rate)
    {
        if ($this->_dState !== SERIAL_DEVICE_SET) {
            trigger_error("Unable to set the baud rate : the device is " .
                          "either not set or opened", E_USER_WARNING);

            return false;
        }

        $validBauds = array (
            110    => 11,
            150    => 15,
            300    => 30,
            600    => 60,
            1200   => 12,
            2400   => 24,
            4800   => 48,
            9600   => 96,
            19200  => 19,
            38400  => 38400,
            57600  => 57600,
            115200 => 115200
        );

        if (isset($validBauds[$rate])) {
            if ($this->_os === "linux") {
                $ret = $this->_exec(
                    "stty -F " . $this->_device . " " . (int) $rate,
                    $out
                );
            } elseif ($this->_os === "osx") {
                $ret = $this->_exec(
                    "stty -f " . $this->_device . " " . (int) $rate,
                    $out
                );
            } elseif ($this->_os === "windows") {
                $ret = $this->_exec(
                    "mode " . $this->_winDevice . " BAUD=" . $validBauds[$rate],
                    $out
                );
            } else {
                return false;
            }

            if ($ret !== 0) {
                trigger_error(
                    "Unable to set baud rate: " . $out[1],
                    E_USER_WARNING
                );

                return false;
            }

            return true;
        } else {
            return false;
        }
    }
Configure the Baud Rate
Possible rates : 110, 150, 300, 600, 1200, 2400, 4800, 9600, 38400,
57600 and 115200.

@param  int  $rate the rate to set the port in
@return bool