title: How to read data from serial port and write to serial port?
body: <p>Hi I'm writing an application in c# to connect to a device via rs232(com) port. I need to send a "read" command to read data from it and a "write" command to send some data to it.</p>
  
  <p>I read some articles in here and some other sites and I know there are some methods when I'm defining a serial port in c#.</p>
  
  <p>but my question is ,should I be concerned about DTR ,RTS ,... ?
  what are they for? How do I use them? </p>