Controlling a stirrer with RS232

Ok, I implemented the code:

//Copy from: https://forum.arduino.cc/t/rs232-to-ttl-converter-for-weighing-scale-not-working-solved/567570/114

#include <SoftwareSerial.h>

SoftwareSerial mySerial(0, 1); // RX, TX <------< Use the pins you want

void setup()
{
  // Open serial communications and wait for port to open
  Serial.begin(1200);
  // set the data rate for the SoftwareSerial port
  mySerial.begin(1200);
  // asks for Read Type Information of unit
  Serial.write("1RTY1"); Serial.write(13);
}

void loop()
{
    while (mySerial.available())
    {
     
      Serial.write(mySerial.read());   // You can also use: Serial.print((char)mySerial.read());
      delayMicroseconds(200);
    }
}

And I'm getting nothing back:

I tried the format as suggested in the manual (1,RTY,1) but also nothing back. Although I tried as well with the stirrer in operation (in case that would get it to talk), still got no response.

Btw I will download CoolTerm because it's indeed pretty annoying having to compile/upload every change to Arduino.