EXP Computer C4077-90960 - Manual (Page 123)

Printer Input Sources
Paper Size Switches
The paper guides in Trays 2 and 3 operate four levers at the back of the
trays which activate the size sensing switches (SW1601 through SW1604)
mounted in the printer chassis. Table 5-8 compares paper sizes to switch
conditions.
Printing from Trays 2 and 3
The Pickup, Feed, and Separation rollers start rotating when the DC
Controller receives the /PRNT signal from the Formatter PCA. Then, the
DC Controller activates the Pickup Solenoid (SL1) and starts feeding paper
through the Paper Input Unit (PIU), triggering photosensors PS2, and then
PS1. These sensors inform the DC Controller that paper has passed
through the PIU and is present at the Registration Assembly.
When the Laser/Scanner and Fuser are ready, the DC Controller sends the
/VSREQ signal to the Formatter. When the Formatter has processed the
print data, it sends the /VSYNC and /VDO signals to the DC Controller.
The paper is then released from the Registration Assembly (by CL1), and
fed to the photosensitive drum, starting the image transfer and fusing
processes. After the paper passes through the Fuser, it triggers PS1403,
and PS1402 to the specified type, size, and destination of the paper being
fed through the printer.
Paper Size SW1601 SW1602 SW1603 SW1604
Ledger (portrait) OFF OFF OFF OFF
A3 (portrait) OFF ON OFF OFF
B4 (portrait) ON OFF OFF OFF
Legal (portrait) ON ON OFF OFF
Letter (landscape) OFF OFF OFF ON
A4 (landscape) OFF OFF ON OFF
Table 5-8 Paper Size Switches
5-38 Functional Overview