Basic Sequences - Canon CANOSCAN N1220U Service Manual

CHAPTER 2
D. Basic Sequences
The basic sequences of the scanner are divided into power ON sequence, calibration
sequence, and document scanning sequence.
1. Power ON sequence
Sets analog power
Tests gate array
Gate array read/write
was tested normally?
Scanning unit is in home
2 - 4
COPYRIGHT 2000 CANON INC.
Power ON
Sets gate array
Checks PCB ID
Checks CIS
read/write
NO
YES
NO
position?
Returns scanning unit
YES
Scanning unit returned
to the home position?
Stops scanning unit
1
Figure 2-4-1
CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)
Sets error flag
NO
YES
Returned more
than 300 mm?
Sets error flag
NO
YES