Hardware design, Communication parameters, Endpoints – ACS ACR1283L User Manual
Page 8: Contact smart card interface, Smart card power supply vcc (c1), Card type selection, Interface for microcontroller-based cards, Table 1 : usb interface wiring
ACR1283L – Reference Manual
Version 1.00
www.acs.com.hk
Page 8 of 55
4.0. Hardware Design
4.1. USB
The ACR1283L is connected to a computer through a USB following the USB standard.
4.1.1. Communication Parameters
The ACR1283L is connected to a computer through USB as specified in the USB Specification 2.0.
The ACR1283L 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 ACR1283L and PC.
3
D+
Differential signal transmits data between ACR1283L and PC.
4
GND
Reference voltage level for power supply.
Table 1: USB Interface Wiring
Note: In order for ACR1283L to function properly through USB interface, the driver should be
installed.
4.1.2. Endpoints
The ACR1283L uses the following endpoints to communicate with the host computer:
Control Endpoint For setup and control purpose
Bulk OUT
For command to sent from host to ACR1283L (data packet size is 64 bytes)
Bulk IN
For response to sent from ACR1283L to host (data packet size is 64 bytes)
Interrupt IN
For card status message to sent from ACR1283L to host (data packet size is 8
bytes)
4.2. Contact Smart Card Interface
The interface between the ACR1283L and the inserted smart card follows the specifications of ISO
7816-3 with certain restrictions or enhancements to increase the practical functionality of the
ACR1283L.
4.2.1. Smart Card Power Supply VCC (C1)
The current consumption of the inserted card must not be higher than 50 mA.
4.2.2. Card Type Selection
Before activating the inserted card, the controlling PC always needs to select the card type through
the proper command sent to the ACR1283L. This includes both memory card and MCU-based cards.
For MCU-based cards the reader allows to select the preferred protocol, T=0 or T=1. However, this
selection is only accepted and carried out by the reader through the PPS when the card inserted in
the reader supports both protocol types. Whenever a MCU-based card supports only one protocol
type, T=0 or T=1, the reader automatically uses that protocol type, regardless of the protocol type
selected by the application.
4.2.3. Interface for Microcontroller-based Cards
For microcontroller-based smart cards only the contacts C1 (VCC), C2 (RST), C3 (CLK), C5 (GND)