Serial.read and serial.print through rs232 connection+Ektapro slide projector.

Hello,

I am using a serial port to send 8 bit packets of hex numbers to an ektapro kodak slide projector. This projector sends me three hex numbers back of which the last one indicates its position.
It works with cutecom and a usb rs232 port (see image, the projector is on position hex 12 (= decimal 18))

When try to do the same with my arduino (+ rs232 shield) I am able to send the hex command (FD 00 00) but I am not able to read it back through serial.read() and serial.print(). The only thing I get is -1 or FFFFFFFF or 11111111 depending on the kind of data I specify.

Pretty sure I am doing something wrong with the code.
I need the third hex number of the data package converted to a decimal number.

#include <SoftwareSerial.h>
SoftwareSerial projector1(3, 2); // RX, TX


int gettrayposition ()
{
  byte hex[] = {0xFF,0xA0,0x00};
  projector1.write(hex,sizeof(hex));
  Serial.print(Serial.read(), HEX);
}

void setup() {
  projector1.begin(9600);
  Serial.begin(9600);
}

void loop() {
  gettrayposition();
  delay(5000);
}

You’re not waiting to see if any serial data is available before you try reading it.

{
  byte hex[] = {0xFF,0xA0,0x00};
  projector1.write(hex,sizeof(hex));
while (serial.available()<2){
// wait for data
}
// 3 byte ready now
  Serial.print(Serial.read(), HEX); // 1st byte
Serial.print(Serial.read(), HEX); // 2nd byte
Serial.print(Serial.read(), HEX); // 3rd byte
}