Epson Printer Integration Guide

This POS system integrates with Epson thermal receipt printers via the ePOS SDK.

Architecture

Files

• resources/js/epos-2.20.0.js - Epson ePOS SDK library (253KB)
• resources/js/store/modules/printing.js - Vuex module for print management
• resources/js/store/modules/epos.js - Device connection management
• resources/js/printing.js - Legacy printing utilities

Connection Details

• IP Address: 192.168.200.80
• Port: 8008
• Protocol: ePOS Device Service

Vuex Store Structure

State

state: {
    ePosDev: null,           // ePOS device instance
    printer: null,           // Printer object
    printingNotification: false,
    printingAttempts: 0,
    printing: {
        order: null,         // Current order being printed
        invoice: null,       // Current invoice being printed
    },
    printingHistory: []
}

Key Actions

// Connect to printer
this.$store.dispatch('setEpsonDevice')

// Print an order (kitchen ticket)
this.$store.dispatch('setPrintingOrder', order)

// Print an invoice (receipt)
this.$store.dispatch('setPrintingInvoice', invoice)

Connection Flow

// In printing.js store module

setEpsonDevice({ commit, state }) {
    const ePosDev = new epson.ePOSDevice();

    ePosDev.connect('192.168.200.80', 8008, (result) => {
        if (result === 'OK' || result === 'SSL_CONNECT_OK') {
            ePosDev.createDevice('local_printer',
                ePosDev.DEVICE_TYPE_PRINTER,
                { crypto: false, buffer: false },
                (printer, code) => {
                    if (code === 'OK') {
                        printer.timeout = 60000;
                        commit('setEpsonDevice', { ePosDev, printer });
                    }
                }
            );
        }
    });
}

Receipt Formatting

Order Ticket (Kitchen)

// Header
printer.addTextAlign(printer.ALIGN_CENTER);
printer.addTextSize(1, 2);
printer.addTextStyle(false, false, true, printer.COLOR_1);
printer.addText('TABLE NAME\n\n');

// Time
printer.addTextSize(1, 1);
printer.addText(` Vreme: ${time}\n`);

// Items
printer.addTextSize(1, 2);
printer.addText(' —————————————————\n');
items.forEach(item => {
    printer.addText(` ${item.qty} x ${item.name}\n`);
});

// Cut
printer.addFeedLine(1);
printer.addCut(printer.CUT_FEED);

Invoice Receipt

// Header
printer.addText('PREDRAČUN\n');  // "Bill" in Serbian

// Items with prices
items.forEach(item => {
    printer.addText(formatLine(item.name, item.total));
});

// Totals
printer.addText('—————————————————\n');
printer.addText(formatLine('UKUPNO:', total));
printer.addText(formatLine('PDV (20%):', tax));

// Receipt number
printer.addText(`\nBroj: ${receiptNumber}\n`);

// Cut
printer.addCut(printer.CUT_FEED);

Helper Functions

// Right-align text with spacing
function printerTextBetween(left, right, width = 48) {
    const spaces = width - left.length - right.length;
    return left + ' '.repeat(spaces) + right;
}

// Format price
function formatPrice(price) {
    return new Intl.NumberFormat('de-DE').format(price);
}

Error Handling

// Sentry integration for error tracking
import * as Sentry from '@sentry/vue';

printer.onreceive = (response) => {
    if (!response.success) {
        Sentry.captureException(new Error('Print failed'));
        commit('setPrintingNotification', true);
    }
};

// Retry logic
if (state.printingAttempts < 3) {
    commit('incrementPrintingAttempts');
    dispatch('setEpsonDevice');
}

Printer Commands Reference

// Text formatting
printer.addTextAlign(printer.ALIGN_LEFT | ALIGN_CENTER | ALIGN_RIGHT);
printer.addTextSize(width, height);  // 1-8 each
printer.addTextStyle(reverse, underline, bold, color);

// Line spacing
printer.addTextLineSpace(pixels);  // Default ~30
printer.addFeedLine(lines);

// Paper cutting
printer.addCut(printer.CUT_FEED);     // Feed then cut
printer.addCut(printer.CUT_NO_FEED);  // Cut without feed

// Send to printer
printer.send();

Troubleshooting

1. Printer not connecting: Check IP/port, ensure printer is on network
2. Print jobs stuck: Call disconnect() and reconnect
3. Garbled text: Ensure UTF-8 encoding for Serbian characters
4. Slow printing: Check buffer: false setting

Real-time Notifications

The printing module shows a notification when:

• Print job is in progress
• Print job fails (with retry option)
• Timeout after 30 seconds