SCH2 Technical Manual TSP016.doc Issue 3.0 – January 2005
Money Controls 2005. All rights reserved.
Page 10 of 61
8. Why
Serial
?
Coin hoppers traditionally have a simple parallel interface. Common methods for paying out
coins include ‘logic motor control’ whereby a low voltage control signal can be used to turn the
motor on and off, and ‘pulse counting’ whereby a stream of pulses is used to dispense the coins
( one coin per pulse ). In the ‘logic motor control’ method it is up to the host software to monitor
and count coins travelling past the payout optos.
Security for the parallel interface method is poor for a determined hacker. Simply drilling a hole
in the cabinet and applying suitable voltages to the interface connector or cables can be used to
empty the hopper of coins. A hopper with a serial interface is usually resistant to this means of
attack due to the sheer complexity of the ‘dispense coins’ instruction.
Another benefit of ‘multi-drop’ serial is the ability to connect several coin hoppers to the same
wiring harness or ‘bus’. This greatly simplifies the cabling within a machine as multiple hoppers
can be daisy-chained together rather than having to branch out from a central star point. The
number of control signals is usually much less with serial than with parallel. The only control
signal in the ccTalk protocol is a single bi-directional ‘data’ line. It is also possible with serial to
connect in other money transaction peripherals such as coin acceptors, bill validators and card
readers.
The inherent ‘expandability’ of serial allows for a much better level of diagnostics and error
reporting than is available on parallel, if it is available at all. Rather than a general alarm
condition, the difference between a coin jam and a deliberate attempt to fraud the hopper can
be reported externally.
Please Note:-
A version of Serial Compact Hopper 2 is available WITHOUT Encryption.
Please refer to cctalk.org for further information.
Summary of Contents for SCH2
Page 8: ......
