Hi, yout post is quit old but I changed your code a bit. Now it sends the status of both relays:

long double last_heartbeat_time = millis();
long double HEARTBEAT_TIME = 30000;

int oldValue = 0;
bool state;

MyMessage msg1a(1, V_STATUS);
MyMessage msg1b;

MyMessage msg2a(2, V_STATUS);
MyMessage msg2b;

void before() {
  for (int sensor = 1, pin = RELAY_1; sensor <= NUMBER_OF_RELAYS; sensor++, pin++) {
    // Then set relay pins in output mode
    pinMode(pin, OUTPUT);
    // Set relay to last known state (using eeprom storage)
    digitalWrite(pin, loadState(sensor) ? RELAY_ON : RELAY_OFF);
  }
}

void setup() {

}

void presentation()
{
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("Relay", "1.0");

  for (int sensor = 1, pin = RELAY_1; sensor <= NUMBER_OF_RELAYS; sensor++, pin++) {
    // Register all sensors to gw (they will be created as child devices)
    present(sensor, S_BINARY);
  }
}


void loop()
{
  long double temp = (millis() - last_heartbeat_time);
  if (temp > HEARTBEAT_TIME) {
    // If it exceeds the heartbeat time then send a heartbeat
    sendHeartbeat();
    send(msg1a.set(msg1b.getBool() ? 1 : 0));
    send(msg2a.set(msg2b.getBool() ? 1 : 0));
    last_heartbeat_time = millis();
    Serial.println("Sent heartbeat" );
  }
}

void receive(const MyMessage &message) {

  // We only expect one type of message from controller. But we better check anyway.
  if (message.type == V_STATUS) {
    // Change relay state
    digitalWrite(message.sensor - 1 + RELAY_1, message.getBool() ? RELAY_ON : RELAY_OFF);
    // Store state in eeprom
    saveState(message.sensor, message.getBool());
    // Write some debug info
    Serial.print("Incoming change for sensor:");
    Serial.print(message.sensor);
    Serial.print(", New status: ");
    Serial.println(message.getBool());

    if (message.sensor == 1) {
      msg1b = message;
    }

    if (message.sensor == 2) {
      msg2b = message;
    }

  }
}

rg Denis