SCH2 Technical Manual TSP016.doc Issue 3.0 – January 2005
Money Controls 2005. All rights reserved.
Page 23 of 61
12.1 Power Fail in Detail
The sequence of saving the coin counters to NV Memory is triggered by the following
conditions…
¾
Sudden loss of power with the motor running
¾
Receipt of an ‘Emergency stop’ command
If power is suddenly lost with the motor running then the hopper will stop the motor
immediately and update the NV Memory while it has power to do so. SCH2 does not have a
‘battery back-up’ but uses a capacitor reservoir.
If power is lost after a payout sequence has completed ( hopper in idle ) then the
[ Last payout : coins unpaid ] counter is cleared, regardless of the value it was holding. This
is because it is assumed the host machine has dealt with the last payout sequence and
taken appropriate action. It is not desirable to flag unpaid coins during the next power-up
initialisation.
Note:- This means a slow rise time or switch bounce on the power supply could
inadvertently clear the unpaid counter.
If the host machine has early notification of a power fail it can send an ‘Emergency stop’
command to the hopper. This command stops the motor dead and returns the number of
unpaid coins back to the host. This value
should be stored by the host machine
prior to
power being lost.
Examples…
a) Power lost during payout sequence
Counter
Initial value
Pay 3 from 10
then lose power
Last payout : coins paid
0
3
Last payout : coins unpaid
0
Î
7
Í
Hopper dispense count
0
3
Hopper life dispense count
N
N + 3
Coins remaining = 7
Continued…
Summary of Contents for SCH2
Page 8: ......
