Canon imageRUNNER ADVANCE 4551i Service Manual page 135

Width Length
LDR 279.4 431.8
Also, the cassette presence is detected when the size switch is pushed.
(If no switch is pushed, it is determined as no cassette.)
Setting method when the size detection patterns are overlapped
ASize should be found manually on the check screen for the combination of A5-Rand STMT-R or the combination of B5-R and
EXEC.
Specify the ecognition method for the special paper with user setting.
Paper level sensor
Paper level in a cassette is detected with the sensor indicated below.
Name
Cassette paper level sensor A
Cassette paper level sensor B
Cassette paper sensor
Cassette paper
level sensor B (S4/S34)
Paper sensor flag
Width detection(S28/S35)
① ②
OFF ON
S4/S32
S3/S34
S2/S31
Cassette paper
sensor (S2/S31)
Cassette paper
level sensor A (S3/S32)
Lifter gear
③ ④ ①
ON OFF OFF
Symbol
Flag
Tray
122
2. Technology
Length detection(S29/S30)
② ③
OFF ON
④
ON