Canon LBP-1210 Service Manual page 120

CHAPTER 2
The CPU determines a failure or an error under the following conditions and notifies it to the
interface controller.
1) Scanner failure
If the /BDI signal is not detected within 1.5 seconds after the scanner motor is forcibly driv-
en, the CPU extends the time to 120 seconds. If the signal cycle does not reach its specified
value within these 120 seconds, the CPU determines a scanner failure.
2) BD failure
The CPU determines a BD failure if the /BDI signal is not detected within 0.1 second after
the scanner motor is forcibly driven. Or, if the detected cycle of the /BDI signal has not
reached the specified value within 2 seconds after the scanner motor reached its specified
rotation number.
3) BD error
While the CPU is outputting the /BD signal to the interface controller, if the detected cycle
of the /BDI signal has not reached its specified value, the CPU determines a BD error. Note
that if a door open is detected within 0.2 second after BD error detection, the CPU does not
notify the interface controller of the error. Also, the CPU cancels the BD error when a scan-
ner or BD failure is detected after the error.
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