Lexmark X422 User Reference Manual page 207

Standard USB
Network/USB – Standard USB
Menu item
PCL SmartSwitch
PS SmartSwitch
NPA Mode
Using the MFP control panel and menus
Purpose
To configure the MFP so it
automatically switches to
PCL emulation when a print
job received through the USB
port requires it, regardless of
the default printer emulation.
To configure the MFP so it
automatically switches to
PostScript emulation when a
print job received through the
USB port requires it,
regardless of the default
printer emulation.
To specify whether the MFP
performs the special
processing required for
bidirectional communication,
following the conventions
defined in the Network
Printing Alliance (NPA)
Protocol.
Values and descriptions
On*
Off
On*
Off
On
Off
Auto*
Menus
207
MFP examines the data on the
USB interface and selects
PCL emulation if the data
indicates that is the required
printer emulation.
MFP does not examine the
incoming data. The MFP uses
PostScript emulation to process
the job if PS SmartSwitch is On,
or uses the default printer
emulation specified in the Setup
Menu if PS SmartSwitch is Off.
MFP examines data on the USB
interface and selects
PostScript emulation if the data
indicates that is the required
printer emulation.
MFP does not examine the
incoming data. The MFP uses
PCL emulation to process the
job if PCL SmartSwitch is On, or
uses the default printer
emulation specified in the Setup
Menu if PCL SmartSwitch is Off.
MFP performs NPA processing.
If data is not in NPA format, it is
rejected as bad data.
MFP does not perform NPA
processing.
MFP examines the data to
determine the format and then
processes it appropriately.