Multiple RFID readers on Mega + Ethernet Shield

Projects Networking, Protocols, and Devices
7

So I need use this "SoftwareSerial"?
How I could connect it?

I tried it already, but I don't know that it was good connected.

I tried this way:

RFID SDA - pin 12
RFID MISO - pin 13
Other pins were not changed.

#include <SoftwareSerial.h>

SoftwareSerial mySerial(12, 13); // RX, TX

void setup() {
  // Open serial communications and wait for port to open:
  Serial.begin(57600);
  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.begin(4800);
  mySerial.println("Hello, world?");
}

void loop() { // run over and over
  if (mySerial.available()) {
    Serial.write(mySerial.read());
  }
}

It was only for test and I din't have any reply, probably i didn't add any libraries?
How can I write this program?

Thank you very much for reply!