# Frontend operations¶

## General rules¶

To change the frontend Local Oscillator frequency, use the following command:

> setLO=[freq1];[freq2];…;[freqN]


Notice the semicolon. Ideally, different values could be assigned to different IFs, thus tuning each section to a different sub-band. For the present hardware, though, this is not possible, so a single value must be specified:

e.g. > setLO=22000

Remember that the actually observed band begins at a frequency which is usually different from the LO one (see Initial setup)

The temperature of the calibration mark in use is recorded in the logfile whenever a Tsys is measured. It is also stored in the FITS output files. The calibration mark can be manually switched on and off respectively with:

> calOn
> calOff


If the user wants to perform the setup for the frontend only (without affecting the mount, the minor servo or the backend), the command is:

> receiversSetup=[code]   (CCC, CCL, CHC, CHCL, XXP, KKC)