Returns eTrue if the device is in energy saving sleep
mode, otherwise returns eFalse. Setting SLEEP-MODE to
eFalse causes the device to wake up, if it is in sleep
mode. Setting SLEEP-MODE to eTrue causes the device to
go into sleep mode.
Additional information:
Setting this object to eTrue while the printer
is awake will not change the printer's current state
and will return <genErr>
status.
Setting to eTrue while printer is already in
the Sleep Mode will not change the printer's
current state and will return <noError> status.
Setting to eFalse while printer is already awake
will not change the printer's current state and will
return <noError> status.