Communication with scale via rs232

Question

I need help with an Arduino project. I want to read values from a TCS150 scale using the serial port. The hardware I have is an UNO R3 board and a MAX3232 level converter.

I have connected:

MAX3232 power supply - 5V from UNO R3 TX -> D10 When checking the voltage on the TX cable connected to UNO, it varies between 3.5V and 4.2V, so there shouldn't be any connection problem. I tried to upload a simple program as shown in the picture, but I can't receive any values So far, I haven't found a solution. The incoming data when I plugged in scale to computer via Putty is correct. Do you know where I might have made a mistake in connecting or programming the Arduino?

Program:

#include <SoftwareSerial.h>
SoftwareSerial mySerial(10,-1);  // -1 if not using TX to save a pin

void setup()
{
   Serial.begin(9600);
   Serial.println("<Arduino is ready>");
   mySerial.begin(9600);
}

void loop()
{
  if(Serial.available()) {
    Serial.println("serial available");
  } else {
    Serial.println("serial not available");
  }

  if(mySerial.available()) {
    Serial.println("myserial available");
  } else {
    Serial.println("myserial not available");
  }
  string x = mySerial.readString();
  Serial.println(x);
  delay(1000);
}

The output is:
-> serial not available
-> myserial not available
-> ? (question mark in rhombus)