Soft dB SPM PLL User Guide - Manual (Page 13)

SPM - PLL User’s Manual 13
Select the desired bandwidth and click ok. Then, the interface will automatically set the LP filter (for the
phase/frequency), the PI gains and the time constant of the phase/amplitude detector to reach the
desired bandwidth.
For the amplitude controller, the following dialog box allows specifying the desired bandwidth:
To be able to determine the proper PI gains, the auto-adjustment function must know the gain at the
resonance and the Q factor of the resonator. These values can be measured with the Resonator
Sweep function. The interface will automatically set the LP filter (for the amplitude signals), the PI gains
and the time constant of the phase/amplitude detector to reach the desired bandwidth.
4.7 Loop-Response-Test Controls
Theses controls allow the testing of the loop response of both controllers. These controls can be used
only if the corresponding controller is engaged. The test function measures the step response of the
controller. An adjustable step is applied on the set-point and the resonator phase or output amplitude is
recorded during the test. The Amp. step and Phase step are used to define the amplitude of the step.
For instance, if the Phase step control is set to +3, the controller set-point will be stepped up by +3 deg
for the test. The set-point step is returned to zero after the test. The Test button launches the following
interface (phase controller case):