This enum type describes the receiver’s scanning line time. Possible values are:
SLN_NOCHANGE Does not change settings.
Other values in SLN_<Num1>N<Num2>F format, where ‘N’ means normal resolution,
‘F’ means fine resolution, Num1 and Num2 are in milliseconds:
SLN_0N0F,SLN_5N5F,SLN_10N5F,SLN_10N10F,SLN_20N10F,
SLN_20N20F,SLN_40N20F,SLN_40N40F.