Document Title Here
Document Title Here
Document Title Here
ACR33U-A1 SmartDuo Reference Manual
Version 1.00
Page 8 of 56
www.acs.com.hk
6.0. USB Interface
The ACR33U-A1 SmartDuo is connected to a computer through a USB following the USB standard.
6.1. Communication Parameters
The ACR33U-A1 SmartDuo is connected to a computer through USB as specified in the USB
Specification 2.0. The ACR33U-A1 SmartDuo is working in full speed mode, i.e. 12 Mbps.
Pin
Signal
Function
1
V
BUS
+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 1:
USB Interface Wiring
Note:
In order for the ACR33U-A1 SmartDuo 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 SmartDuo 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)
Table 2:
ACR33U-A1 SmartDuo Communication Endpoints
