CLOUD
47
X
0
F
R
EFERENCE
M
ANUAL
16
3.6.
Contactless communication principles and CLOUD
47x0 F usage recommendations
CLOUD 47x0 F is a dual interface reader capable of reading both contact smart cards and
contactless user tokens. The following paragraph focuses on a few specifics of contactless
communication to outline usage recommendations in order to ensure best user experience.
CLOUD 47x0 F is a contactless reader
1
designed
to
communicate
with
user
credentials.
User credentials
2
are made of a contactless
integrated circuit chip connected to an
antenna
User credentials can take several form
factors:
Credit card sized smart card
Key fob
USB token
NFC mobile phone etc…
Communication between CLOUD 47x0 F and user credentials uses magnetic field inductive
coupling.
The magnetic field generated by CLOUD 47x0 F has a carrier frequency of 13.56MHz.
3.6.1. Power supply
When the user credential is put in the magnetic field of the reader, its antenna couples with the
reader and an induction current appears in the antenna thus providing power to the integrated
circuit. The generated current is proportional to the magnetic flux going through the antenna of
the user credential.
3.6.2. Data exchange
The carrier frequency of the magnetic field is used as a fundamental clock signal for the
communication between the reader and the credential. It is also used as a fundamental clock
input for the integrated circuit microprocessor to function.
To send data to the user credential the reader modulates the amplitude of the field. There are
several amplitude modulation and data encoding rules defined in ISO/IEC 14443. The reader
should refer to the standard for further details.
To answer the reader, the integrated circuit card of the user credential modulates its way of
loading (impedance) the field generated by the reader. Here also further details can be found in
ISO/IEC 14443.
1
In the ISO/IEC 14443 standard, the reader is called the proximity coupling device (PCD)
2
In the ISO/IEC 14443 standard, the user credential is called proximity integrated chip card (PICC)
C
L
O
U
D
4
7
x0
F
User tokens
CLOUD 47x0 F
