User Manual
UM0001-1B.00 June 17, 2002
User Manual for the CTS Tri-Reader 1-1
CHAPTER 1 CTS Tri-Reader
TM
1.1 Introduction
The Cubic Transportation Systems, Inc. (CTS) Tri-Reader will serve as a front end for a
remote ticketing device used for automatic fare collection (AFC) in public transportation
systems (e.g., bus, rail, subway, etc.). It can be used in ticket validators, ticket vending
machines, gates, and other AFC equipment. This equipment can be onboard vehicles or in
fixed ground locations. The Tri-Reader will be responsible for direct communication with
a Contactless Smart Card (CSC), which is a type of radio frequency (RF) tag. The
naming refers to the fact that the design caters for at least three types of CSC, namely
Type A, Type B, and
GO CARD
®
.
Interpretation of the information stored on the CSC, as well as the processing of the
revenue collection transaction, will not be done by the Tri-Reader itself, but rather by the
central processing unit (CPU) to which it is a slave. Unsolicited messages will only be
passed from the Tri-Reader to the CPU when the unit is told to search for and report any
CSCs found to be present. Beyond establishing the card's presence and performing
collision detection, the Tri-Reader will be a “dumb” data link between the CPU and the
card.
The firmware on the Tri-Reader is designed to be updated in-system using FLASH-based
technology. It will therefore be possible to cater, within limits, for different CSC types and
configurations — if so required for the future.
In broad terms, the communication task will therefore proceed as follows:
1. The Tri-Reader will power the CSC through radiation by an induced RF field.
2. By sequencing through the communication protocols for the different cards, it
will detect the card type by checking for the associated response.
3. Once the card type and therefore its communication mechanism is known, the
Tri-Reader will communicate the card type to the CPU.
4. The Tri-Reader will pass data to and from the CSC by using the appropriate
protocol for modulation and demodulation of the signal.