Table of Contents
Advertisement
Scanning timing
The CPU turns ports P50, P51, P52, and P53 Low in this order. When not Low, those
ports are High or in high impedance. When a particular port out of them is Low, the CPU
reads the status of port P20.
The CPU scans those key contacts every 10 ms. If the CPU reads the ON state on an
input port two successive times, then it interprets it as the key being pressed; if the CPU
reads the OFF state six successive times, it interprets it as the key being released.
The input mode of this keying system is 2-key roll-over and 3-key lockout.
Figure 3.2-5 Key Scan Timing Scheme and Scanning Pulse Outputs
Solder points
The CPU reads the solder point status once in the powering-in sequence to recognize the
customization.
Solder points 1 through 5 customize the machine for the destination (shipping country).
06 Netherlands (Holland)
05 Belgium
04 Switzerland
03 France
01 Germany
Spec
Destination
No.
10 U.S.A./Canada
Spec
Destination
No.
H: Solder point opened
L: Solder point closed
Solder points A through C are reserved for the future use for the thermal head ranking.
According to the soldered status, the CPU determines the ON-time length of the thermal
print head.
H
H
H
H
L
H
H
H
L
H
H
H
L
H
H
L
H
H
H
H
H
L
H
H
H
1
2
3
4
5
Solder Points
H
H
H
H
H
1
2
3
4
5
Solder Points
III - 5
08 Spain
07 Italy
02 England/Ireland
Spec
Destination
No.
12 Sweden
11 Norway
09 Denmark
Spec
Destination
No.
H
L
H
H
H
L
H
H
H
H
H
H
H
H
H
1
2
3
4
5
Solder Points
H
H
L
H
H
H
L
H
H
H
L
H
H
H
H
1
2
3
4
5
Solder Points
Hide quick links:
Advertisement
Chapters
Table of Contents
Troubleshooting
