ACS ACK30 Smart Keyboard - Manual (Page 8)

ACR30 Reference Manual
Version 3.3 January 2009 Page 8 of 44
ACR30
4.0. Smart Card Interface
The interface between the ACR30 and the inserted smart card follows the specifications of ISO7816-3
with certain restrictions or enhancements to increase the practical functionality of the ACR30.
4.1. Smart Card Power Supply VCC (C1)
The current consumption of the inserted card must not be higher than 50mA.
4.2. Programming Voltage VPP (C6)
According to ISO 7816-3, the smart card contact C6 (VPP) supplies the programming voltage to the
smart card. Since all common smart cards in the market are EEPROM based and do not require the
provision of an external programming voltage, the contact C6 (VPP) has been implemented as a
normal control signal in the ACR30. The electrical specifications of this contact are identical to those
of the signal RST (at contact C2).
4.3. Card Type Selection
The controlling PC has to always select the card type through the proper command sent to the ACR30
prior to activating the inserted card. This includes both the memory cards 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 an 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.
4.4. Interface for Microcontroller-based Cards
For microcontroller-based smart cards only the contacts C1 (VCC), C2 (RST), C3 (CLK), C5 (GND)
and C7 (I/O) are used. A frequency of 3.6864 / 4 MHz is applied to the CLK signal (C3).
4.5. Card Tearing Protection
The ACR30 provides a mechanism to protect the inserted card when it is suddenly withdrawn while it
is powered up. The power supply to the card and the signal lines between the ACR30 and the card
are immediately deactivated when the card is being removed. As a general rule, however, to avoid
any electrical damage, a card should only be removed from the reader while it is powered down.
NOTE - The ACR30 does never by itself switch on the power supply to the inserted card. This must explicitly be done by the
controlling computer through the proper command sent to the reader.