Money Controls SCH2, Техническое руководство

Страница: 29 / 61

SCH2 Technical Manual TSP016.doc Issue 3.0 – January 2005

Money Controls 2005. All rights reserved.
Page 29 of 61
Product Configuration
Modify variable set Ö set current limit
set motor stop delay
set payout timeout
set single coin payout mode
Default values can be used if so desired in which case this command can be skipped. Single
coin payout mode is more secure though because once in this mode an external bus attack can
at best only pay out a single coin at a time rather than emptying the contents of the hopper. This
assumes all the other security mechanisms have been defeated. However, single coin payout
mode is much slower.
Remove Payout Inhibit
Enable hopper Ö prepare for payout by allowing the dispense command
Check for Residual Payout from a Power Fail
Test hopper Ö check for NV Memory write fail or checksum error
If { counter error } then
Write data block Ö if good host copy exists then correct counter
else
Request hopper status Ö check to see if there are residual coins after last
payout. If so then take the decision to pay out the balance.
Optional… Request hopper dispense count Ö check with last known host
copy to see if an illegal payout has been made
Errors in the hopper memory should not occur under normal operating conditions. If one of the
counters become corrupted however it would be possible to restore their contents if the host
machine has a backup copy.
Dispense Coin
Test hopper Ö check error flags are clear
If { error flags } then
< take appropriate action on possible fraud attempt >
Reset device
Ö
clear error flags
Enter PIN number Ö if enabled
Modify variable set Ö set current limit, stop delay, timeout, single coin mode
Enable hopper Ö re-enable hopper after reset
Pump RNG Ö send some random numbers to the hopper
Request cipher key Ö ready for encryption algorithm
Dispense hopper coins Ö pay out one or more coins
If { Dispense NAK } then
Something went wrong - find out why ?
Continued…