Owner manual

ACR33U-A1 – Reference Manual [e-mail]
Version 1.02
www.acs.com.hk
Page 9 of 60
6.0. USB Interface
6.1. Communication Parameters
The ACR33U-A1 is connected to a computer through USB as specified in the USB Specification 2.0.
The ACR33U-A1 is working in full speed mode, i.e. 12 Mbps.
Pin Signal Function
1 VBUS +5 V power supply for the reader
2 D- Differential signal transmits data between ACR33U-A1 and PC
3 D+ Differential signal transmits data between ACR33U-A1 and PC
4 GND Reference voltage level for power supply
Table 2: USB Interface Wiring
Note: In order for the ACR33U-A1 to function properly through USB interface, either ACS proprietary
device driver or ACS PC/SC device driver has to be installed.
6.2. Endpoints
The ACR33U-A1 uses the following endpoints to communicate with the host computer:
Control Endpoint
For setup and control purpose
Bulk OUT
For command to be sent from host to ACR33U-A1
(data packet size is 64 bytes)
Bulk IN
For response to be sent from ACR33U-A1 to host
(data packet size is 64 bytes)
Interrupt IN
For card status message to sent from ACR33U-A1 to host
(data packet size is 8 bytes)