rs 232 / TTL coverter not working

i have an rs232 / ttl converter and i cannot get it to output the rs232 data to the arduino

the rs232 data is being send from a tracking device

i can connect the rs232 port to the usb / serial adaptor and i am able to output the data being transmitted to screen. I am using a third party serial monitor software to read the rsa232 data So this proves the tracking device is outputting the data correctly

when i unplug the d9 connector from the serial / usb adaptor and connect it to the d9 of the rs232 / ttl connector the data does not appear on the arduino monitor

below is my sketch i am trying

any advise would be appreciated i have been working on this for days and i cannot get it working

Software serial multple serial test

Receives from the hardware serial, sends to software serial.
Receives from software serial, sends to hardware serial.

The circuit:

  • RX is digital pin 10 (connect to TX of other device)
  • TX is digital pin 11 (connect to RX of other device)

Not all pins on the Mega and Mega 2560 support change interrupts,
so only the following can be used for RX:
10, 11, 12, 13, 50, 51, 52, 53, 62, 63, 64, 65, 66, 67, 68, 69

Not all pins on the Leonardo and Micro support change interrupts,
so only the following can be used for RX:
8, 9, 10, 11, 14 (MISO), 15 (SCK), 16 (MOSI).

created back in the mists of time
modified 25 May 2012
by Tom Igoe
based on Mikal Hart’s example

This example code is in the public domain.

#include <SoftwareSerial.h>

SoftwareSerial mySerial(10, 11); // RX, TX

void setup() {
// Open serial communications and wait for port to open:
while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only

Serial.println(“Goodnight moon!”);

// set the data rate for the SoftwareSerial port
mySerial.println(“Hello, world?”);

void loop() { // run over and over
if (mySerial.available()) {
if (Serial.available()) {

You may need to swap pins 2 & 3 between the DB9 on the RS232/TTL converter and the RS232 cable.

Unfortunately with SoftwareSerial it is not possible to do a loopback test on the RS232/TTL converter to verify if those connections are correct, SoftwareSerial has problems with receiving its own send data.