User's Manual

33
The following layout illustrates the operating sequence for the remote control:
Request
Require
Computer
Server
Execute
Command
(1)
(2)
(3)
(
4
)
WI Client WI Server
A)
B)
C)
Synchronize
Read
Write + Data
Command
R
e
s
p
o
n
s
e
A
)
B
)
C
)
S
y
n
c
h
r
o
n
i
z
e
n
u
m
b
e
r
R
e
a
d
d
a
t
a
N
u
m
b
e
r
w
r
i
t
t
e
n
d
a
t
a
Figure 5.6 –Challenge/Response Sequence for remote control
1. In the first phase the client sends a request to the server.
2. The server answers the request by generating a response containing the request for a command in the shape of
an encrypted string; these are some possible commands:
a. Synchronize enables synchronizing the server with the progressive number of the remote token
b. Read enables carrying out reading operations from the token memory
c. Write enables carrying out writing operations on the token; together with the command also the
writable data is transmitted
3. The client decrypts and interprets the string transmitted by the server and executes the command requested.
4. The client stores the result of the command into an encrypted string and sends it to the server, which can
control the execution of the command; the response depends on the type of requested command and is
described by the following list:
a. The response to the Synchronize command is the progressive number stored by the token.
b. The response to the Read command is the information requested by the token memory.
c. The response to the Write command is the operation status.