Introduction

The ACR122U is a PC-linked contactless smart card reader/writer used for accessing ISO 14443-4 Type A and Type B, MIFARE®, ISO 18092, and FeliCa tags. The ACR122U is PC/SC compliant making it compatible with existing PC/SC applications. The ACR122U serves as the intermediary device between the computer and the contactless tag via the USB interface. The reader carries out the command from the computer whether the command is used to communicate with a contactless tag, or control the device peripherals (LED or buzzer). This API document will discuss in detail how the PC/SC commands were implemented for the contactless interface and device peripherals of the ACR122U.

• Built-in antenna for contactless tag access, with card reading distance of up to 50 mm (depending on tag type)
• Support for ISO 14443 Part 4 Type A and B cards, MIFARE, FeliCa, and all four types of NFC (ISO/IEC 18092 tags)
• Built-in anti-collision feature (only one tag is accessed at any time)
• Application Programming Interface:
• Supports PC/SC o Supports CT-API (through wrapper on top of PC/SC)
• Built-in Peripherals: o User-controllable bi-color LED
• User-controllable buzzer o Supports Android™ 3.1 and above
• Compliant with the following standards:
• IEC/EN 60950
• ISO 18092
• ISO 14443
•  CE
• FCC
• KC
• VCCI
• MIC
• PC/SC
• CCID
• Microsoft® WHQL
• RoHS 2