Most POS problems in the first week are not software problems. They are a scanner that types into the wrong field, a cash drawer that never opens, or a printer that drops off the network every afternoon. A careful hardware setup prevents nearly all of them.
This checklist covers each device on a typical retail counter — what to buy, how it connects, how to test it — plus networking, power and a troubleshooting table you can keep behind the till.
In this guide
How POS hardware fits together
Think of the counter as a hub-and-spoke layout. The POS computer is the hub; everything else connects to it directly or through the network. One detail surprises many first-time buyers: the cash drawer usually connects to the receipt printer, not the computer.
The POS computer or tablet
This device runs the POS software and, in an offline-first setup, holds the database. Choose for reliability rather than raw power:
- An operating system supported by your POS software (check the vendor’s list — for example Windows 10/11, macOS or Android tablets).
- A solid-state drive (SSD) for speed and durability.
- Enough USB ports for scanner, printer and display, or a powered USB hub.
- A wired Ethernet port if the computer will host the database for other tills.
- A touchscreen if staff will tap product buttons; a mouse works for low-volume counters.
Dedicate the computer to the POS. Personal browsing, games and unknown downloads on the till computer are a common source of slowdowns and security problems.
Barcode scanners
Most retail scanners connect by USB and operate in keyboard (HID) mode: the scanner “types” the barcode digits followed by Enter, exactly as if a person had typed them. That is why they usually work without drivers — and why the cursor must be in the POS search or barcode field when you scan.
| Scanner type | Best for | Notes |
|---|---|---|
| Handheld 1D (laser/linear) | Standard product barcodes | Affordable; cannot read QR codes |
| Handheld 2D imager | Product barcodes + QR codes, phone screens | Good default choice today |
| Presentation / countertop | High-volume checkouts | Hands-free scanning |
| Wireless (Bluetooth/2.4 GHz) | Large or heavy items | Check range and charging cradle |
Test: open a text editor and scan a product — the digits should appear followed by a new line. Then scan in the POS and confirm the right product is added. If the suffix is wrong or characters are missing, most scanners can be reconfigured by scanning setup barcodes from their manual.
Receipt printers
Retail receipt printers are almost always thermal: no ink, just heat-sensitive paper. The two common paper widths are 80 mm (standard receipts, more columns) and 58 mm (compact counters). Most models use the ESC/POS command language, which the majority of POS software supports.
| Connection | Pros | Cons |
|---|---|---|
| USB | Simple, plug-and-play | Tied to one computer |
| Ethernet (LAN) | Shared by several tills, stable | Needs a fixed IP address |
| Wi-Fi / Bluetooth | No cables | Less reliable at busy times |
For a single till, USB is fine. For two or more tills, or a kitchen printer, Ethernet is usually the more reliable choice. Configure the printer in your POS settings, then print a test receipt and check the header, footer and paper cut.
Cash drawers
A standard cash drawer connects to the receipt printer with an RJ11/RJ12 (telephone-style) cable. When the POS completes a cash sale, it sends a “drawer kick” command to the printer, which sends an electrical pulse to open the drawer.
- Check that the drawer and printer use compatible connectors and voltage (most are 24 V).
- Enable “open drawer on cash payment” in the POS printer settings.
- Test with a cash sale. If the drawer does not open, try the drawer’s manual key and swap the cable before blaming the software.
Customer displays
A customer-facing display shows items and the total as they are scanned, which reduces disputes and speeds up payment. Options include a two-line pole display, a small second monitor, or a second screen built into an all-in-one terminal. Connect it, set it as the customer display in the POS, and check that it shows the basket during a test sale.
Some POS systems can also show promotions on the customer display between sales.
Label printers
If you sell loose, repackaged or imported goods without usable barcodes, a label printer pays for itself quickly. Direct-thermal label printers are the most common choice for shelf and product labels; thermal-transfer printers (with a ribbon) produce longer-lasting labels for items stored in heat or sunlight.
- Choose label sizes that match your shelf strips and product types before buying rolls in bulk.
- Print barcodes from the POS catalogue so the barcode on the shelf always matches the product record.
- Scan a freshly printed label at the till to confirm it reads first time.
See how labels are generated from your product list on the barcode labels page, and why consistent product identification matters in our retail inventory management guide.
Card terminals
Card terminals are supplied or approved by your payment provider. From a security standpoint, the safest arrangement for a small shop is a standalone, provider-approved terminal so that card numbers never pass through the POS computer. The PCI Security Standards Council lists approved payment devices, and your provider will tell you which self-assessment questionnaire applies to your setup.
- Place the terminal where customers can reach it comfortably and where the cashier cannot see PIN entry.
- Connect it to a stable network — wired if possible — and keep it away from guest Wi-Fi.
- Learn its offline behaviour before you need it: some terminals can store payments during an outage, with limits and risk on the merchant.
- Record the payment method in the POS for every card sale so cash and card totals reconcile.
Counter layout and ergonomics
A good layout shaves seconds off every sale. Place the scanner on the cashier’s dominant-hand side, keep the receipt printer within reach without stretching, and position the cash drawer so it can open fully without hitting knees or shelving. Turn the customer display towards the queue, and route cables under the counter with cable ties so nothing gets unplugged by accident. Finally, leave space for bagging — a crowded counter slows everyone down.
Networking and power
Even a single till benefits from a tidy network. With several tills, it becomes critical.
- Use wired Ethernet for the main computer, fixed tills and network printers.
- Give the main computer and network printers fixed (reserved) IP addresses in the router.
- Keep POS devices on a separate network from guest Wi-Fi.
- Put the main computer, router and switch on a UPS so a short power cut does not interrupt sales.
- Label every cable at both ends.
- Keep a 4G/5G hotspot available for card terminals and updates during an outage.
For setups with more than one till, follow the multi-terminal POS setup guide.
Troubleshooting common hardware problems
| Symptom | Likely cause | Fix |
|---|---|---|
| Scan does nothing | Cursor not in the search field | Click the POS search/barcode field and rescan |
| Wrong product or extra characters | Scanner suffix or keyboard layout | Reconfigure the scanner suffix (Enter) and keyboard language |
| Receipt prints garbled text | Wrong printer driver or code page | Select the correct printer model/ESC/POS mode in the POS |
| Printer offline after a while | IP address changed (DHCP) | Reserve a fixed IP for the printer in the router |
| Cash drawer does not open | Cable, voltage, or kick disabled | Check the RJ11 cable, enable drawer kick, test manually |
| Customer display blank | Display not selected in settings | Choose the second screen in the POS display settings |
| Other tills cannot connect | Firewall or changed host IP | Allow the POS through the firewall; reserve the host IP |
Complete POS hardware setup checklist
- Computer meets the POS requirements; SSD; dedicated to the POS.
- POS software installed and tested with demo data.
- Scanner tested in a text editor and in the POS.
- Receipt printer configured; test receipt prints with correct header/footer.
- Cash drawer opens on a cash sale.
- Customer display shows the basket.
- Fixed IPs reserved for the main computer and network printers.
- UPS installed for computer, router and switch.
- Label printer configured if you print barcode or price labels.
- Backups scheduled and one restore tested.
- Five test sales completed, including a cancellation and a reprint.
Need help deciding what to buy in the first place? Start with what a POS system is and how to choose one. To print your own barcodes, see barcode labels.
Test your scanner, printer and cash drawer before you commit: the free edition includes printer configuration tools and demo data.
Frequently asked questions
Do barcode scanners need drivers?
Usually not. Most USB scanners work in keyboard (HID) mode and appear to the computer as a keyboard. They type the barcode into whichever field is active.
How does the cash drawer open?
Most cash drawers connect to the receipt printer with an RJ11/RJ12 cable. The POS sends a drawer-kick command to the printer, which triggers the drawer.
Should I choose an 80 mm or 58 mm receipt printer?
80 mm printers are the retail standard and fit more columns per line. 58 mm printers suit very small counters or mobile setups.
Is Wi-Fi good enough for POS devices?
Wi-Fi works for tablets and handheld devices, but fixed tills, the main computer and network printers are more reliable on wired Ethernet.