Im WSCST ist die Papiergröße für ein Fach anzugeben und dann dieses Fach anzusteuern:

Drawer Page Size
The DWRPAGSIZ (drawer page size) tag defines the size of the paper present in a
specific source paper drawer.
In raster mode, this paper size is used to allocate the raster page buffer. The SCS
to ASCII transform uses this paper size to determine if COR mode is required.
If the drawer size is not defined, the host print transform uses the page size that is
specified in the AS/400 print job.
You can define a drawer size for one or more of the source drawers. You begin
support for the drawer page size with the DWRPAGSIZ tag and end the support
with the EDWRPAGSIZE tag. The DWRPAGSIZE tags fall between, defining a
drawer and its size.
Using the drawer page size tags, your source could look something like this for a
printer supporting two different source drawers.
:DWRPAGSIZ.
:DWRPAGSIZE...
:DWRPAGSIZE...
:EDWRPAGSIZ.
The following sections describes the tags used to support different drawer sizes.
Drawer Page Size (DWRPAGSIZ) Tag
The DWRPAGSIZ tag defines the page size for a source drawer. This tag must be
followed by one or more DWRPAGSIZE tags that contain the drawer size. There
are no parameters on this tag. The syntax is:
:DWRPAGSIZ.
Drawer Page Size Entry (DWRPAGSIZE) Tag
The DWRPAGSIZE tag defines the page size for a particular source drawer. The
DWRPAGSIZ tag must be follows by one or more DWRPAGSIZE tags. The
EDWRPAGSIZE tag must follow a group of DWRPAGSIZE tags. The syntax is:
:DWRPAGSIZE
DRAWER = 0-255
PAGWTH = Page width
PAGLEN = Page length.
DRAWER
This is a required parameter. This parameter defines the source drawer.
0 The envelope drawer is specified.
1-255 The drawer 1-255 is specified.
PAGWTH
This is a required parameter. This parameter specifies the drawer page width in
1/1440 inch increments. This value must be an integer. The width is the
left-to-right dimension of a piece of paper.
PAGLEN
This is a required parameter. This parameter specifies the drawer page length
1/1440 inch increments. This value must be an integer. The width is the
top-to-bottom dimension of a piece of paper.
End Drawer Page Size (EDWRPAGSIZ) Tag
The EDWRPAGSIZ tag is used to end a group of drawer page size entries in the
customizing source. There are no parameters on this tag. The syntax is:
:EDWRPAGSIZ.