Unable to connect Grove RFID reader and Base Shield

Hi,
I’m trying to use the grove rfid reader.
I plugged the base shield on the arduino mega card, and plugged the reader to the UART slot.
To initialize it I’ve to use the command SoftwareSerial RFID(0, 1); // RX and TX but I don’t know what part are used by the base shield. I’ve made a script to try to find the correct pins but It don’t work, It never say he find the right combination of pins.

#include <SoftwareSerial.h>
SoftwareSerial RFID(0, 1); // RX and TX

int i;

void setup()
{
  RFID.begin(9600);    // start serial to RFID reader
  Serial.begin(9600);  // start serial to PC
  Serial.println("Started");
}

void loop()
{
  if (RFID.available() > 0)
  {
    Serial.println("Reading");
    i = RFID.read();
    Serial.print(i, DEC);
    Serial.print(" ");
  }
  else
  {
    for (int rx = 0; rx < 75; rx++) {
      for (int tx = 0; tx < 75; tx++) {

        SoftwareSerial RFID(rx, tx);
        RFID.begin(9600);

        if (RFID.available()>0)
        {
          Serial.print("Find !");
          Serial.print(rx);
          Serial.print(" ");
          Serial.println(tx);
          delay(10000);
        }
        else {
          Serial.print(rx);
          Serial.print(" ");
          Serial.println(tx);
        }
      }
    }
  }

}

Dont use pins 0,1 for softareserial. Those pin related to Serial (hardware).

Select other pins.. example: http://www.seeedstudio.com/wiki/Grove_-_125KHz_RFID_Reader

Even using the script in the example I get nothing …

..and you read this:

Uart Mode (Jumper set to the left two pins)

You would need to select the jumper to "U" to enter this mode, and the setting is: 9600bps, N, 8, 1, TTL output

The jumper is set to N, 9600 bps is set here : SoftSerial.begin(9600); But I don't know what the N, 8, 1 and TTl output means ...

I've tried

SoftwareSerial SoftSerial(1, 8);
and
SoftwareSerial SoftSerial(8, 1);

But always the same problem.

SoftwareSerial name(2,3); // name and pinnumbers then: name.begin(speed); // No parity, 8 databits, 1 stopbit is defalt and taken care of.. You have the example code - at least it compiles OK Only thing I can think of now, is connections Arduino pin2 (RX) to shields TX, pin3(TX) to RX, in addition to GND and 5V lines..

I4m using a base shield ANd there is only one UART port. It's connected to the Tx0 and Rx0 of the arduino mega board. I can't change that.