HP PCL/PJL reference (PCL 5 Printer Language) - Technical Reference Manual Part I

4-12 PCL Job Control Commands EN
Output Bin Selection Command
The Output Bin Selection command selects either of the two output
paper bins (upper or lower [rear]) for paper output.
? & l # G
# = 1 - Upper Output Bin
2 - Lower (Rear) Output Bin
Default = Upper Output Bin
Range = 1, 2
Note If this command is received by a printer which does not contain the
dual output bin feature, it is ignored.