How to Set Up a POS Counter — Small Business Hardware Checklist

A POS counter looks simple from the customer's side — a screen, a scanner beep, a receipt. Behind that counter, five or more hardware devices need to be connected correctly and talking to each other before the first transaction can process. Getting this wrong means a cash drawer that will not open, a printer that jams, or a scanner that reads barcodes the software cannot recognize. This guide walks through every piece of hardware on a small business POS counter, how they connect, and the setup mistakes that cause problems on day one.

What Hardware Goes on a POS Counter

A complete POS counter has a core set of hardware components. Each serves a specific function, and skipping one usually means a workaround that slows down every transaction.

POS terminal — The main unit with a touchscreen display, processor, storage, and I/O ports. This is the hub that every other device connects to. For a fixed counter, a 15-inch all-in-one desktop terminal with an aluminum alloy enclosure is the standard choice — fanless, durable, and built for 12–16 hours of continuous daily operation.

Receipt printer — A thermal printer that produces paper receipts. It also serves a second function: triggering the cash drawer to open via an RJ11 pass-through cable. Most commercial receipt printers connect to the terminal via USB or a serial (COM) port. Thermal printers use heat instead of ink, so there are no cartridges to replace — only paper rolls.

Barcode scanner — Reads product barcodes and sends the data to the POS terminal. For a fixed counter, a wired USB scanner is more reliable than wireless — no battery to charge, no Bluetooth pairing issues, and instant response. Handheld models work for most retail; presentation (hands-free) scanners are faster for high-volume grocery or convenience store counters.

Cash drawer — Stores cash, coins, and sometimes checks. The drawer connects to the receipt printer (not the terminal) via an RJ11 cable. When a transaction completes, the POS software sends a print command, and the printer simultaneously sends an electrical pulse to pop the drawer open. No separate power supply needed.

Network connection — An Ethernet cable from the terminal's RJ45 port to your router or switch. This carries transaction data to your POS software's server or cloud backend. Wired Ethernet is more stable than Wi-Fi for a fixed counter — no dropped connections during peak hours, no interference from kitchen equipment.

Optional Hardware (Add Based on Your Business Type)

Customer-facing display — A second small screen (7–10 inches) or a simple VFD pole display that shows the transaction total to the customer. Useful for transparency and checkout speed, but not essential for every business. A VFD pole display costs $10–$15 and connects via COM port; a full LCD screen costs $30–$80 and uses a video output (VGA or HDMI).

Payment terminal — A card reader for credit/debit cards and contactless payments. This device is typically provided by your payment processor (not by the POS terminal manufacturer) and connects to the terminal via USB or sits on its own network connection. Your POS software needs to support the specific payment terminal model your processor provides.

Kitchen display or kitchen printer — For restaurants and cafes, orders need to reach the kitchen. A kitchen display system (KDS) shows orders on a screen; a kitchen printer produces paper tickets. Both connect via your local network. The KDS is the modern approach — no paper waste, orders can be bumped and prioritized on screen.

Self-service kiosk — For quick-service restaurants or retail stores with high foot traffic, a self-service kiosk lets customers place orders or check out independently. This is a separate hardware unit with its own screen, payment reader, and receipt printer — not connected to the counter terminal.

How Everything Connects

The POS terminal is the center of the setup. Every peripheral connects to it (except the cash drawer, which connects through the printer). Here is the standard wiring for a typical small business counter:

The key detail most setup guides skip: the cash drawer connects to the receipt printer, not to the POS terminal. If your terminal does not have a direct RJ11 port, that is normal — the drawer gets its signal from the printer. If your terminal does have an RJ11 port, that port is also designed to trigger the drawer directly; check your POS software documentation for which method it supports.

Five Setup Mistakes That Cause Problems on Day One

1. Not running an end-to-end test before opening. Each device may power on fine individually, but the real test is a complete transaction cycle: scan a barcode, process a sale, print a receipt, verify the cash drawer opens. Run this test at least five times. If any step fails, you will find out during your first rush instead of during a calm setup window.

2. Plugging the cash drawer RJ11 into the wrong port. Some receipt printers have two RJ11 ports — one input (from the terminal, rarely used) and one output (to the cash drawer). Plugging the drawer cable into the input port means the drawer will never receive the open signal. Check the printer manual for which RJ11 port is the drawer trigger.

3. Using Wi-Fi for a fixed counter. Wi-Fi seems simpler because there is no cable to run, but it introduces connection drops, latency spikes, and interference — especially in restaurants where microwaves and metal equipment disrupt the signal. A single Ethernet cable from the terminal to your router eliminates all of these issues.

4. Not installing peripheral drivers before connecting devices. Most POS terminals running Windows require drivers for receipt printers and sometimes for scanners. Plugging in a printer before installing its driver can result in the OS assigning a generic driver that does not support the printer's cash drawer trigger function. Install the manufacturer's driver first, then connect the hardware.

5. Forgetting to set the barcode scanner's keyboard mode. Many USB barcode scanners default to "keyboard wedge" mode, which types the barcode digits as if someone is typing on a keyboard. Most POS software expects this mode, but some require the scanner to be set to serial emulation or a specific data format. If scanned barcodes appear in the wrong field or with extra characters, the scanner's communication mode needs to be reconfigured — usually by scanning a setup barcode from the scanner's manual.

Minimum Port Requirements for Your Terminal

Before purchasing a POS terminal, count the peripherals you plan to connect and verify the terminal has enough ports. Here is the minimum for a standard small business counter:

USB ports: 3 minimum — one for the barcode scanner, one for the receipt printer (if USB), one for the payment terminal or a spare. Four to six USB ports give you room to add peripherals later without a hub.

COM (serial) port: 1 minimum — for legacy printers, VFD customer displays, or specialized peripherals. Even if you plan to use all USB devices now, having one COM port available prevents compatibility issues later.

RJ45 Ethernet: 1 — for wired network connectivity.

Video output (VGA or HDMI): 1 — only needed if you plan to use a customer-facing LCD display. Skip this if you are using a VFD pole display (which uses COM) or no customer display at all.

For a detailed breakdown of how port count, enclosure material, and other specs affect terminal pricing, see the budget POS terminal buying guide. When sourcing terminals from a manufacturer, always request the full I/O specification sheet before confirming your order.

Frequently Asked Questions