EthercatDevice_XXX.getSlaveNo()

#include "Ethercat.h"

EthercatMaster master;
EthercatDevice_QECR11DF0S slave;

void setup(void) {
    int getSlaveNo;
    
    Serial.begin(115200);
    while (!Serial);
    
    master.begin();
    slave.attach(0, master);
    master.start();
    getSlaveNo = slave.getSlaveNo();
    Serial.println(getSlaveNo);
}

void loop() {}