@Override
    public int read(final byte[] dest, final int timeout) throws IOException {
        if(dest.length == 0) {
            throw new IllegalArgumentException("Read buffer too small");
        }
        return read(dest, dest.length, timeout);
    }
use simple USB request supported by all devices to test if connection is still valid
usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/driver/CommonUsbSerialPort.java