How to get MAC address info from embedded c?

Code:
void SystemInfo(){ RFID_HANDLE32 readerManagementHandle; RFID_STATUS rfidStatus = RFID_API_SUCCESS; LOGIN_INFO loginInfo; READER_TYPE readerType = FX; BOOLEAN secureMode=0; READER_SYSTEM_INFO SystemInfo;
wcscpy(loginInfo.userName, L"admin"); wcscpy(loginInfo.password, L"change"); wcscpy(loginInfo.hostName, L"localhost");
loginInfo.forceLogin = true; loginInfo.version = RFID_API3_5_1;
if(RFID_API_SUCCESS == RFID_Login(&readerManagementHandle, &loginInfo, readerType, secureMode, NULL)) {  rfidStatus = RFID_GetSystemInfo(readerManagementHandle, &SystemInfo);
  wprintf(L"\nFirmware: %ls",SystemInfo.radioFirmwareVersion);  wprintf(L"\nSN: %ls",SystemInfo.serialNumber);  wprintf(L"\nMAC: %ls",SystemInfo.networkInfo->MACAddress);
  RFID_Logout(readerManagementHandle); // Logout so that Dll is cleaned up }}

resule:
Firmware: 2.7.19
SN: XXXXXXXXXXX(mark)
MAC: false