GO sets the values of the switching_signals_master, cal_state, sig_ref_state, blanking_time, number_of_phases, switch_period, and phase_start YGOR parameters in the Scan Coordinator manager. The AdvanceTime, AdvanceSig1, and AdvanceSig2 YGOR parameters only exist in the DCR manager and are set within the DCR manager by GO. The switchDeltas YGOR parameter only exists within the LO1 manager and is set within the LO1 manager by GO using the settings of the switchDeltas, num_fsw_offsets, ref_freq_1 and ref_freq_2 GO Keywords. The xferState YGOR parameters currently exists only in the 2 cm and 1 cm receivers and is set within the receiver managers using the GO Keyword beam_ctrl. The calState YGOR parameter currently exists only in the 2 cm and the 1 cm receivers and is set within the receiver managers using the GO Keyword cal_ctrl.
When a switching signal parameter is set in the Scan Coordinator manager, the value is passed down to each device which also uses these parameters. GO reads back the value from the device. This forms a requested value - actual value cycle between GO, the Scan Coordinator manager and the Device manager. This allows the observer to know what the switching signals are in each device for their observations.
N.B. The request value - actual value cycle is not used to update the switch_mode GO Keyword. The switch_mode GO Keyword is intended to aid the observer in the overall setup of the GBT and is not guaranteed to reflect the actual state of the system. The switch_mode GO Keyword is used to derive the SWSTATE and SWTCHSIG GO FITS Keywords.
When one of the ``User Defined'' modes of switch_mode is selected then the observer will be allowed to set all of the switching signal GO keywords. However, when switch_mode is selected to be one of the non-''User Defined'' modes GO will disable the setting of most of the switching signal GO Keywords from the GO GUIs.