How a price checker connects to store systems: serial, USB and network
A price checker hands the barcode to the application in three ways: serial (RJ11 to DB9), USB (keyboard emulation or virtual COM) and network (HTTP / TCP interfaces). Which one to use depends on how the store system already connects: POS software usually expects serial, web apps go over the network, and USB keyboard emulation is the quickest way to validate.
Comparison and fit
| Connection | Physical port | Data format | Fit | Watch out for |
|---|---|---|---|---|
| Serial | RJ11 COM (RJ11-DB9 adapter included) | Serial byte stream, parsed by the application protocol | Stores that already run POS or price lookup software and use serial peripherals | Set baud rate, data bits and terminator; pinout follows the adapter |
| USB keyboard emulation | USB 2.0 / 3.0 | Barcode characters are typed at the cursor | Quick validation, light web apps | The input field must have focus; cannot read composite codes with control characters |
| USB virtual COM | USB 2.0 / 3.0 | Serial byte stream (CDC) | Needs USB convenience with protocol control | The OS needs a driver or built-in CDC support |
| Network | RJ45 / WiFi | HTTP requests, a persistent TCP connection or MQTT, depending on the application | Fleet management, cloud price tables | Plan IPs and ports, and keep the internal network separated from the internet |
What happens to the data after one scan
- The engine decodes the barcode into a string and passes it to the local application over serial or USB.
- The application identifies the code type (in-store code, national standard code or manufacturer code) and applies any prefix handling.
- The application checks a local cache (price table) or calls the store system (POS, ERP, product middleware).
- It receives name, specification, price and stock, renders them on screen and writes the query to a log when needed.
- Logs flow back to the back-end system on demand, showing which products are looked up most and which positions are underused.
Four questions integrators ask
Can we get the scan data?
Yes. Serial and virtual COM deliver a raw byte stream, USB keyboard emulation delivers keystrokes, and the network option pushes data over an agreed protocol. The protocol is fixed at project start.
Can it be locked to a single app?
Yes. On Android we use a dedicated launcher and kiosk mode; on Windows, a restricted account plus a unified write filter boots straight into your application.
Can it be updated remotely?
Yes. Application updates can be automated; push system images only when necessary and keep a rollback path. Multiple units can be managed from one device management platform.
Can you preload our certificates?
Enterprise certificates, WiFi profiles and proxy settings can be preloaded per project to cut on-site setup work.
Integration FAQ
We use our own POS system. Can it integrate?
Yes. The usual pattern is for the price checker to send the barcode to your server over serial or the network, and the server returns the product data. We provide interface documentation and debugging support; the protocol follows your system.
Do we need drivers?
USB keyboard emulation needs no driver, since the system sees a keyboard. USB virtual COM may need a driver on Windows; Linux and Android usually include CDC support. Serial needs wiring matched to the adapter pinout.
How do we manage multiple units?
On Android, use MDM or your own management console to push apps and settings. On Windows, use domain policy, remote desktop or a third-party endpoint management tool. Assign fixed IPs or DHCP reservations so units are easy to locate.
Can the price checker connect to a printer directly?
Yes. The 802 series has a USB port for a receipt printer; the XTCM320 has a built-in 80mm printer with cutter. The application controls what is printed.
Can customers see or take the data?
The screen shows only the fields you choose. Query logs stay on the device or go back to the back-end system and are not exposed publicly. Mask personal data such as member phone numbers.
Request interface docs and debugging support
Tell us what your system is (web, desktop client or cloud platform) and we will set out the integration method in writing.