title: JavaPOS printing text throws JposException
body: <p>I had a lot trouble to setup a applet to work with an Epson TM-T88V pos printer. Now I can send the command for the cutter and it works. But printing any other text is not possible. </p>
  
  <p>The following jpos.JposException occurs:</p>
  
  <pre><code>jpos.JposException: UnicodeDLL:-10An undefined parameter value was set.  
    at jp.co.epson.upos.T88V.pntr.T88VService.createNormalData(Unknown Source)  
    at jp.co.epson.upos.core.v1_13_0001.pntr.CommonPrinterService.executeNormalPrint(Unknown Source)  
    at jp.co.epson.upos.T88V.pntr.T88VService.printNormal(Unknown Source)  
    at jpos.POSPrinter.printNormal(Unknown Source)  
    at de.develman.pos.printer.Printer.printReceipt(Printer.java:58)  
    at de.develman.pos.ui.action.PrintAction.actionPerformed(PrintAction.java:22)  
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)  
    ...
  </code></pre>
  
  <p>My code looks as follows:</p>
  
  <pre><code>private void initPrinter() throws JposException {
      ptr.open("POSPrinter");
      ptr.claim(1000);
      ptr.setDeviceEnabled(true);
      ptr.setMapMode(POSPrinterConst.PTR_MM_METRIC);
  }
  
  private boolean printerUseable() throws JposException {
      // check if the cover is open
  if (ptr.getCoverOpen() == true) {
      // cover open so do not attempt printing
      System.out.println("printer.getCoverOpen() == true");
      return false;
  }
  
  // check if the printer is out of paper
  if (ptr.getRecEmpty() == true) {
      // the printer is out of paper so do not attempt printing
      System.out.println("printer.getRecEmpty() == true");
      return false;
  }
  
      return true;
  }
  
  public void printReceipt() {
      try {
          initPrinter();
          if (printerUseable()) {
              ptr.printNormal(POSPrinterConst.PTR_S_RECEIPT, "1\n");
              ptr.printNormal(POSPrinterConst.PTR_S_RECEIPT, PAPERCUT);
          }
      } catch (JposException e) {
          // display any errors that come up
          e.printStackTrace();
      } finally {
          // close the printer object
          try {
              ptr.setDeviceEnabled(false);
              ptr.release();
              ptr.close();
          } catch (Exception e) {
      }
  }
  </code></pre>
  
  <p>The exceptions points to the line:</p>
  
  <pre><code>ptr.printNormal(POSPrinterConst.PTR_S_RECEIPT, "1\n");
  </code></pre>
  
  <p>If I run the code from eclipse everything works fine. If I remove the line, the cutter works fine. But if I want to print any text, the given exception is thrown.<br>
  What is my problem here?</p>