Accelerate fwrite in serial port communication

Hi,

I need to use fwrite to send a trigger to a program. I am looking for the fastest way in matlab (no java) to send a packet, when the packet size doesn't matter. Currently fwrite performs in ~0.1 sec. To test speed I send a packet from one computer to another computer and then send a packet back and measure the time. I exclude the run time of the fwrite in computer 2 and get my final times. My code is:

port = serial('COM1','BaudRate',9600);
port.Timeout = 1e3; 
port.DataBits = 8;
fopen(port);
numIter = 100;
time = zeros(numIter,1);
for n = 1:numIter
  timer = tic;
  fwrite(port,1,'uint8');
  fread(port,1);
  time(n) = toc(timer);
end

end

Answer 1

[Walter Roberson]

My prediction: you are not using true serial ports, and are instead using USB (at least on the MATLAB side)

[Noam]

You are right. I am using a usb2RS232 converter. Ill try to connect it to a real COM port.