Hello, I force the zpl language at the beginning of my function, here is the procedure I use. Thanks

public static String sendPrint(String MacAddress, String filePath) {
	Connection connection = new BluetoothConnection(MacAddress);
	String sTrace = "";
	String pageDescriptionLanguage = "pdf";
	String Language = "";
	try {

		connection.open();
		ZebraPrinter printer = ZebraPrinterFactory.getInstance(connection);
		

		boolean isReady = checkPrinterStatus(printer, filePath);
		SGD.SET("device.languages","zpl",connection);
		
		SGD.SET("media.type", "journal", connection);
		
		Language = SGD.GET("apl.enable", connection);
		if (!Language.contains(pageDescriptionLanguage))
		{
			SGD.SET("apl.enable", "pdf", connection);
		}
		else  {
			
			SGD.SET("apl.settings", "dither" ,connection);
			String scale = scalePrint(connection, 9);
			SGD.SET("apl.settings",scale,connection);
			
			SGD.SET("apl.settings", "scale-to-fit no-varlen orient = N" ,connection);
			SGD.SET("apl.settings", "scale-to-fit no-varlen no-text-smooth mct = 0x94",connection);
			
			if (isReady) {
				if (filePath != null) {
					
					printer.sendFileContents(filePath);
				} else {
					sTrace+= "no_pdf_selected";
				}
			} else {
				
				sTrace+= showPrinterStatus(printer);
			}
			
		}
		
		
	} catch (ConnectionException e) {
		e.printStackTrace();
		sTrace+= "no_printer";
	} catch (ZebraPrinterLanguageUnknownException e) {
		e.printStackTrace();
	} finally {
		try {
			connection.close();
		} catch (ConnectionException e) {
			e.printStackTrace();
		}
	}
	return sTrace;
}