ACR3901T-W1 – Reference Manual
Version 1.02
www.acs.com.hk
Page 10 of 100
5.3. USB Interface
The micro-USB port is used to connect the ACR3901T-W1 to the computer as battery charging port.
This port is also used in order for the ACR3901T-W1 to operate in PC-linked mode.
5.3.1.
Communication Parameters
ACR3901T-W1 is connected to a computer through USB as specified in the USB Specification 2.0.
ACR3901T-W1 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 ACR3901T-W1 and computer
3
D+
Differential signal transmits data between ACR3901T-W1 and computer
4
GND
Reference voltage level for power supply
Table 3
: USB Interface Wiring
5.3.2.
Endpoints
ACR3901T-W1 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 ACR3901T-W1
(data packet size is 64 bytes)
Bulk IN
For response to be sent from ACR3901T-W1 to host
(data packet size is 64 bytes)
Interrupt IN
For card status message to be sent from ACR3901T-W1 to host
(data packet size is 8 bytes)
