GP20 Proximity reader

The GP20 reader is an RFID reader that detects proximity cards and tags of 125 kHz, especially usable in all types of  access control systems, both people and vehicles, to allow access to a facility or part thereof, thanks to its small size and low cost.

Technical specifications


  • Power Requirements: 5 ~ 13.5 Volts regulated @ 65 mA typical with a 12V supply. A linear regulator is recommended.
  • Output Interface: Wiegand, Magstripe 9.6K Baud Serial ASCII(RS232)
  • Typical Maximum Read: Range 20cm with ISO card
  • Frequency: 125KHz standard
  • Broadcast Power: Less than 0.5mW
  • Dimensions: 7.8 x 4.3 x 1.5cm
  • Temperature Range: -10 to 60 Deg C

Data structure

Serial ASCII(RS-232) Baud Rate: 9600, No parity (8 data bits) 1stop bit


  • STX (02 HEX)
  • CR LF ETX (03 HEX)


Magstripe Emulation: (ABA Track 2)

  • Speed: Simulated to 40 IPS (Inch per Second)
  • 10 LEADING ZEROS SS DATA (14 DIGITS) ES LRC 10 TRAILING ZEROS Wiegand : (Format-16 Bit)

Output assignment

  • Red: Power + VDC
  • Black: Ground
  • White: Magstripe clock & Wiegand1, with internal 4K7 pull up
  • Green: RS232 data, Magstripe data & Wiegand0, with internal 4K7 pull up (pull up only for Wiegand and Magstripe)
  • Orange: Card Present Output with internal 4K7 pull up
  • Yellow: Program Input
  • Blue: No Connection
  • Brown: No Connection

Output format

  • The output format can be customer programmed. The available formats are Wiegand, Magstripe and Serial ASCII (RS232)


  • Red Power + V
  • Black Ground
  • Green Data0
  • White Data1
  • Yellow Connect to White
  • Orange No Connection


  • Red Power + V
  • Black Ground
  • Green Data
  • White Clock (Strobe)
  • Orange Card Present
  • Yellow Connect to Orange


  • Red Power + V
  • Black Ground
  • Green TX Data
  • Yellow No Connection
  • White No Connection
  • Orange No Connection

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