## Frequency Switch section

This section is enabled and filled in the CLASS observation header if the FITS card OBS_MODE contains the string FSwitch and if a non-null LO throw value is found in the FITS data.

Table: Look-up table between the CLASS Frequency Switch section and the Herschel-HIFI FITS. Depending on the FITS structure (pipeline level), some elements found in a FITS header or in a FITS binary table. FITS names are case sensitive. Some values are not read from the FITS but explicitly set.
CLASS | Type | Value | Default
nphas | I*4 | 2 |
swmod | I*4 | Metacard isFolded (T/F), translated to CLASS internal code | code for False
decal[1] | R*8 | 0.d0 |
duree[1] | R*4 | 1.0 |
poids[1] | R*4 | +0.5 |
decal[2] | R*8 | Column LoThrow else lothrow (level 2.0), or |
|  | Metacard LoThrow else loThrow (level 2.5) |
duree[2] | R*4 | 1.0 |
poids[2] | R*4 | -0.5 |