如何打开连接电脑的现金抽屉

Question

I recently created a java program which prints a receipt and open up the cash drawer that is connected to the printer.

Now I need to open the cash drawer which will be directly connected to the computer via an RJ11.

Since I will not connect the cash drawer to the printer my feedPrinter will be useless. So how can I call and send the cash drawer the commands ?

Here's my code

public String openDrawer()
{
    final byte[] openCD={27,112,0,60,120};
    String s=new String(openCD);
    commandSet+=s;
    return s;
}


public static void main(String args[])
{
    PrinterOptions p=new PrinterOptions();
    p.openDrawer();
    feedPrinter(p.finalCommandSet().getBytes());
}


 private static boolean feedPrinter(byte[] b)
{
    try
    {

        AttributeSet attrSet = new HashPrintServiceAttributeSet(new PrinterName("PRINTERNAME", null));
//what should I change PRINTERNAME to connect directly to cash drawer
        DocPrintJob job = PrintServiceLookup.lookupPrintServices(null, attrSet)[0].createPrintJob();
        DocFlavor flavor = DocFlavor.BYTE_ARRAY.AUTOSENSE;
        Doc doc = new SimpleDoc(b, flavor, null);
        PrintJobWatcher pjDone = new PrintJobWatcher(job);

        job.print(doc, null);
        pjDone.waitForDone();
        System.out.println("Done !");
    }
    catch(javax.print.PrintException pex)
    {

        System.out.println("Printer Error " + pex.getMessage());
        return false;
    }
    catch(Exception e)
    {
    e.printStackTrace();
    return false;
    }
    return true;
}

public String finalCommandSet()
{
    return commandSet;
}

Answer 1

First and foremost, get the drawer/cutter code for your printer from http://keyhut.com/popopen4.htm

Drawer code for my printer is = 27,112,0,100,250

Then, use the code below to open your cash drawer.

public void openCashDrawer() {

        byte[] open = {27,112,0,100,(byte) 250};
//      byte[] cutter = {29, 86,49};
        PrintService pservice = 
        PrintServiceLookup.lookupDefaultPrintService(); 
        DocPrintJob job = pservice.createPrintJob();
        DocFlavor flavor = DocFlavor.BYTE_ARRAY.AUTOSENSE;
        Doc doc = new SimpleDoc(open,flavor,null);
        PrintRequestAttributeSet aset = new 
        HashPrintRequestAttributeSet();
        try {
            job.print(doc, aset);
        } catch (PrintException ex) {
            System.out.println(ex.getMessage());
        }
    }

This should work.

Thank you.

Answer 2

Not sure about the technicalities, but as code comment:

String s = new String(openCD, StandardCharsets.ISO_8859_1);

    feedPrinter(p.finalCommandSet().getBytes(StandardCharsets.ISO_8859_1));

Without specifying the encoding, the default platform encoding is used. Which is a non-portable way of programming. And on a Unicode, machine, say Linux with UTF-8 this would go wrong: the openCD is not a valid UTF-8 byte sequence.

But better of course:

ByteArrayOuputStream commandSet;

public void openDrawer()
{
    final byte[] openCD={27,112,0,60,120};
    commandSet.write(openCD);
}


public static void main(String args[])
{
    PrinterOptions p=new PrinterOptions();
    p.openDrawer();
    feedPrinter(p.commandSet.toByteArray());
}

Answer 3

Since the printer obviously is controlled by Esc sequences, it will work as is. For the printer, a sequence received via serial interface (or whatever) has exactly the same meaning as the same sequence received via a Centronics interface (or whatever).

You simply need to make sure that the new connect transports data correctly, which it has to anyways.

Update:

Be aware, however, that I possibly got you wrong: I thought you refer to connecting the printer via Centronics vs. connecting differently.

You are talking about connecting the cash drawer directly to the computer without using the printer. Then, of course, it will not work without further effort because then the Esc sequence won't be interpreted by the printer, or at least will not open the drawer.

If you provide details about the drawer interface, we all knew more.

Answer 4

The best is to connect the cash drawer to the receipt printer instead of directly to the computer, and sending and ESC command for open should work. If however you cannot do that, I got it to work on some computers by using jnpout32pkg.dll to write directly to the RJ11-port. However, the adress of the RJ11 seems to be different for different hardware, so you have to find out which address to write to. But this approach might also enable you to read if the cash drawer is open or not (which is a new requirement here in norway as of now..)