We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Jedrek R21 RFID reader, rectangular black plastic, RS232 port

Jedrek

Jedrek R21 125 kHz RFID EM4100 TK4100 Reader RS232

SKU CH-XKH6-E65NC

A 125 kHz RFID reader reads EM4100 and TK4100 cards up to 80 mm and sends data over RS232 at 9600 bps

  • TypeKeyless Entry System
  • Reads EM4100 TK4100 cards up to 80 mm
  • RS232 serial link at 9600 bps for simple integration
  • USB port supplies power only no data
  • Buzzer and red-to-green LED show read status
  • Works with access control parking ID systems

RFID Card Reader for Access Control

The Jedrek R21 reads 125 kHz EM4100 and TK4100 cards at up to 80 mm. It connects to a host via an RS232 serial link and draws power from a USB port. The unit is intended for automated parking, personal identification and production access-control projects. Buzzer and LED signals confirm standby and successful reads.

Suits installers adding simple badge entry

The reader only outputs card numbers over RS232 at 9600 bps and cannot send data through its USB connection. It does not support other card formats, Wiegand output or network interfaces. Projects needing encrypted credentials, multi-format reading or Ethernet integration should consider different hardware.

Fixed RS232 interface at 9600 bps

Communication uses 8 data bits, no parity and 1 stop bit with a defined STX/ETX packet structure. The USB port supplies power only and carries no data. Verify that the host system can accept this serial format before deployment.

Highlights

  • Reads EM4100 TK4100 cards up to 80 mm
  • RS232 serial link at 9600 bps for simple integration
  • USB port supplies power only no data
  • Buzzer and red-to-green LED show read status
  • Works with access control parking ID systems

Specifications

TypeKeyless Entry System

Questions about this item

What serial-port cable and power source does the Jedrek R21 reader require?

Connect the reader to a computer with a standard RS232 serial cable; the USB port supplies power only and carries no data.

Which communication settings must be configured in the terminal software before the first read?

Set the port to 9600 bps, no parity, 8 data bits, 1 stop bit; the reader then sends card data in the STX-Length-CardType-SNR-BCC-ETX frame.

Which card types will the reader still accept after years of daily use?

Only EM4100 and TK4100 cards are supported; no other formats will be recognised even if the hardware remains functional.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.