Write and read serial port simultaneously

[Parvathiiii]

how to read the same data that is written to the COMport.

[pincpanter]

Please open a new thread. Probably your question has nothing to do with this old post.

What you mean exactly? Please give details: do you want to read with what: another program? another computer? ...?

[Parvathiiii]

How to write data to the COM port? And also I want to read the same data from it.(which I write to the COM port)

[pincpanter]

---

@Parvathiiii  ha scritto:

And also I want to read the same data from it.(which I write to the COM port)

---

What's the point in doing this? This is nearly nonsensical. You already know what you wrote.

If you insist, you can put a loopback on the serial connector. If the serial port is a two wire RS-485, you even don't need the loopback.

[crossrulz]

As already stated, if using RS232 or RS422, you need a loopback on your port.  For RS323, this means you wire pin 2 to pin 3.  What I typically do for testing a serial port is to use 2 ports with a crossover cable between them.  Then when I write on one port, I can read on the other.

[Mancho00]

Or you can use a null modem emulator, such as com0com

[RTSLVU]

Start here:

How to Perform a Serial Loopback Test

Also watch this video before you begin ANY serial communications programming:

VIWeek 2020/Proper way to communicate over serial