Canon CANOSCAN FB330 series Service Manual page 67

When the scanner is ON, parallel port signals are directly sent to the printer, meanwhile the
scanner monitors the command sent from the host computer.
Host
computer
When the host computer sends the signal to start the communication with the scanner, the
scanner disconnects the control line from the host computer to the printer, meanwhile the
signal sent from the host computer to the printer is ignored.
Host
computer
When the host computer sends the signal to terminate the communication with the scanner,
the scanner stops the operation and disconnects the communication with the host computer.
The scanner reconnects the control line from the host computer to the printer and switches it
to the printer.
COPYRIGHT © 1999 CANON INC. CANOSCAN FB330/FB630 SERIES REV.0 OCT. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Scanner
Monitors
the command
Figure 2-31
Scanner
Disconnected
Figure 2-32
CHAPTER 2
Printer
Printer
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