REVISTA ROMÂNĂ DE AUTOMATICĂ - IPA SA

REVISTA ROMÂNĂ DE AUTOMATICĂ
41
These readers make use of a ACG proprietary
protocol named “Ratatosk”.
For implementation of the vehicle validation
system for the travel cards, the ARC1007
validators were used, which are connected to the
PC through an adaptor RS-485/RS-232. The
adaptor powers on from the serial ports, and
ensures an automatic bidirectional
communication, without software control.
Figure 2 ARC 1007 Validator
For communications between the master console
and the Arcontia validator it is used a low level
protocol, corresponding to the OSI model 2–4,
named Gleipner, which was created by the
validator's manufacturer - Arcontia. The protocol
it is used to send/read simple commands, to the
keyboard and display.
The serial bus can support up to 8 validators
but the ASCII protocol allows the dialog with
one validator at a time (non-bus architecture).
Consequently, the control applications from
the master console implements an internal
multi-tasking in order to communicate in real
time with all the validators.
The default data transfer speed is 57.6 kbit/s
and can reach up to 460.8 kbit/s.
For passenger information regarding the card
validation it was established visual and
audible secquences on the validator.
The validation transactions are stored on the
computer board application in a Microsoft
SQL Server 2005 Compact Edition database
and transmitted to the dispatcher using RDA
(Remote Data Access) sinchronization
operations with the central Microsoft SQL
Server 2005 database.
Microsoft SQL Server 2005 Compact Edition
(SQL Server CE) is the present compact
edition which evolved from Microsoft SQL
Server 2005 Mobile Edition having no
restrictions regarding its use on the desktop
computers.
Microsoft SQL Server 2005 Compact Edition
it is a small database engine with a footprint
of 1.8 MB; it can store single-file databases
up to 4 GB; it supports 128-bits SSL for
security, including the firewalls; it supports
128-bits RSA encryption for devices; it
provides a password encrypted format.
The data propagation from an SQL Server
database to a local SQL Server Compact
Edition database it is called data pull. The
reverse propagation from an SQL Server
Compact Edition database to an SQL Server
it is called data push.
The synchronization process between the two
databases follows the data modifications in
the local database which are then send.
The download of the validation transactions
to the dispatcher it is performed in welldefined
moments, when the vehicles arrive at
the depot. The drivers are authorized by
presenting their card at the service start.
In order to implement the travel card mobile
inspection system it was used a mobile device
PocketPC compatible and a contactless reader
for CompactFlash interface – ARC 1006.
The control transactions are also stored in a local
Microsoft SQL Server 2005 Compact Edition
database. The inspectors are authorized by
presenting their card at vehicle boarding.
The communication between the dispatcher and
and PDA is similar to the communication
between the dispatcher and the vehicle, having
the role to parameterize the PDA. The data
transmission can take place at vehicle departure
or arrival, in this case, simultaneously with the
validation transactions download.
Figure 2 ARC 1006 contactless reader