NetworkReceiptPrinter

This is an library that allows you to print to a network receipt printer using Node network sockets.

What does this library do?

In order to print a receipt on a receipt printer you need to build the receipt and encode it as in the ESC/POS or StarPRNT language. You can use the ReceiptPrinterEncoder library for this. You end up with an array of raw bytes that needs to be send to the printer. One way to do that is using a network connection.

Installation

If you want to use this libary, first install the package using npm:

npm install @point-of-sale/network-receipt-printer --save

In your project you can then import it, if you use ES6 modules:

import NetworkReceiptPrinter from '@point-of-sale/network-receipt-printer';

let receiptPrinter = new NetworkReceiptPrinter();

Or require it, if you are using CommonJS:

let NetworkReceiptPrinter = require('@point-of-sale/network-receipt-printer');

let receiptPrinter = new NetworkReceiptPrinter();

Configuration

When you create the NetworkReceiptPrinter object you can specify a number of options to help with the library with connecting to the device.

Network settings

When a network printer is connected to the network it will get assigned a IP address. Consult the manual of your printer for a method to get the network settings of your printer. Once you have the IP address of your printer, provide them as properties when you instantiate the NetworkReceiptPrinter object:

• host: The IP address of the printer.
• port: The port number of the printer, by default this is 9100.

For example, to connect to 192.168.1.133 using the default port:

const receiptPrinter = new NetworkReceiptPrinter({ 
    host:   '192.168.1.133'
});

Connect to a receipt printer

The actually connect to the printer you need to call the connect() function. To find out when a receipt printer is connected you can listen for the connected event using the addEventListener() function.

receiptPrinter.addEventListener('connected', device => {
    console.log(`Connected to printer`);
});

The callback of the connected event is passed an object with the following properties:

• type Type of the connection that is used, in this case it is always network.

Commands

Once connected you can use the following command to print receipts.

Printing receipts

When you want to print a receipt, you can call the print() function with an array, or a typed array with bytes. The data must be properly encoded for the printer.

For example:

/* Encode the receipt */

let encoder = new ReceiptPrinterEncoder({
    language:  'esc-pos',
    codepageMapping: 'epson'
});

let data = encoder
    .initialize()
    .text('The quick brown fox jumps over the lazy dog')
    .newline()
    .qrcode('https://nielsleenheer.com')
    .encode();

/* Print the receipt */

receiptPrinter.print(data);

Disconnect from the printer

When you are done with printing, you can call the disconnect() function. This will terminate the connection to the printer. If the connection to the printer is closed, the library will emit a disconnected event.

receiptPrinter.addEventListener('disconnected', () => {
    console.log(`Disconnected from the printer`);
});

receiptPrinter.disconnect();

License

MIT