RFID Card Readers for Time & Attendance Systems

The problem: getting a clean ID into the attendance record

Paper sign-in sheets and typed employee numbers produce the same errors: wrong IDs, missing punches and queues at shift change or the start of class. Every one of them has to be corrected by hand before payroll or a school report can run.

Attendance software vendors and integrators also have a hardware problem. Their customers run the software on front-desk PCs, Android tablets, older terminals with a serial port, or wall terminals with a Wiegand input. Nobody wants to install drivers or write device code at every site, and a school or small office may have no one on hand to do it.

How RFID reading solves it

A staff or student badge carries a fixed ID number. The reader reads it in under 200 ms when the badge is presented and passes it to the host in one of three ways:

• USB keyboard emulation types the number at the cursor, as if someone had keyed it in. Any attendance screen, web form or spreadsheet with an ID field can receive it, with no driver and no SDK.
• RS232 sends the number as a framed serial string to software or a terminal that listens on a COM port.
• Wiegand 26/34 sends it to an attendance terminal or controller that accepts an external reader; our Wiegand access control readers fit an entrance clock-in point.

The software matches the ID to a person and records the time. Our 125 kHz and 13.56 MHz readers are read-only and use the ID that is already on the chip, so existing badges work as they are.

One limit is worth stating plainly: a badge identifies a card, not a person. If badge sharing is a concern, have the software ask for a PIN after the card read. The L310-U 125kHz keypad reader and H310-U 13.56MHz keypad reader combine a numeric keypad and a card reader in one USB device, which suits this card-plus-PIN step.

Choosing the right reader

Pick the badge first; the reader follows from it. Readers that type into software are grouped on the keyboard-emulation reader page, and serial models on the RS232 / RS485 reader page.

Integration notes

Keyboard mode. The number goes wherever the cursor is, so the attendance screen must keep focus on the ID field. Test by opening Notepad or Excel and presenting a badge. Keep the host’s input language on English (US) so digits are not remapped. The guide to keyboard-wedge RFID readers covers focus and layout pitfalls, and reading card numbers into Excel covers a no-software setup for small sites.

Number format. The USB desktop and USB-C models on this page output the 10-digit decimal of the 32-bit ID by default. If your existing badges or payroll records use another number, such as a facility code plus card number, the desktop pads, RS232 pads and USB-C readers can be supplied with a custom output format. Check one badge with the Wiegand 26/34 calculator before you order.

Enter after the number. The keypad readers end each card read with Enter, so a form can submit without a click. If your software needs Enter or Tab after the number on another model, say so in your RFQ and we confirm it against the output format.

RS232 models. The L120-R and H110-R connect by DB9 at 9600 bps by default, with 19200 and 115200 selectable; the H110-R uses 8-N-1. Each read is framed between STX (0x02) and ETX (0x03), so your software or terminal must open the COM port and parse the frame.

Android tablets. The H220-C and L220-C, from our USB-C OTG readers for Android, need a tablet with USB OTG support. They read at 0–30 mm from the front or back and type into any app field, including a browser page.

Operating systems. The USB desktop models work as a standard USB keyboard. Listed OS support covers Windows (XP to 10) and Linux; if you need Windows 11 or macOS, ask us to confirm it on a sample before you order.

What to send us for a quote

1. A badge sample or photo, and the chip type if known (EM4100, TK4100, MIFARE Classic).
2. The host at each clock-in point: Windows or Linux PC, Android tablet (model and OTG support), serial terminal, or a terminal with a Wiegand input.
3. The ID format your software or payroll system stores, with one example number.
4. Input details: any suffix after the number (Enter, Tab) and whether staff also key in a PIN or job code.
5. Quantities per site and the number of sites.
6. OEM requirements, such as your branding or a fixed output format for your software. See private-label and custom-output options.

Software vendors that bundle readers with an attendance product can have them supplied with the output their software expects, so customers plug in and start. Price, MOQ and lead time are confirmed in your quotation. Request samples to test with your software, or contact us with the details above.