Brief Description Of The Chip Card Module; Introduction; Chip Card Contact; Power Supply - Seca 664 Service Manual

Brief Description of the Chip Card Module

Introduction

The chip card module belongs to the family of seca electronic modules and is used to write data to and
to read data from chip cards. It works together with the extended display module which contains the
operating functions for chip card handling.
The following block diagram shows the most important function blocks of the module:
SeSAM Bus

Chip card contact

Lowering contacts are used for the card allowing 200 000 insertion cycles. It can communicate with all
memory cards with an extended I²C bus which have been configured according to the memory
structure defined by seca.

Power supply

The required voltage of 3V is supplied via the SeSAM bus.
SeSAM bus
The SeSAM bus connects the module to the other modules. On this bus the stabilized and non-
stabilized supply voltages are available. All relevant data is exchanged via a data and a clock pulse
line. The scale can be switched on or the module can signal that it wishes to send data via a special
start line.

Signal transmitter

The chip card module is equipped with a signal transmitter. It can be activated via software if the
display module used does not have a signal transmitter. A piezo diaphragm is used which is controlled
with a 4 kHz square-wave signal.

Reset circuit

If the supply voltage is applied or the start key is pressed for longer than 10 seconds, a reset signal for
the micro controller is generated.
Fault handling
If faults occur, the SeSAM bus initiates a fault message with the relevant fault code. Furthermore, each
fault message includes the number of the module type on which the fault has occurred and a code
which indicates how long the message is to stay on display and which displays are to be suppressed.
The module type for the chip card module is 5.
The module can generate the following faults:
30-34-00-685
chipcard contact
µC
signal transmitter
1
crystal
oscillator
reset-
circuit
05.02.2002
EE/Jensen