Feedback Parameter List

By changing the Deflection setpointOperator-selected threshold used as the target of the feedback control loop., you can adjust the cantilever deflection voltage maintained by the feedback loop in Contact AFMImage mode. This parameter defines the center of the range of Cantilever Deflection Voltages that can be collected.

If the Data Center = 0, then the setpoint is at the center line of the force plot. Changing the setpoint shifts the force calibration curve on the graph. For example, if the setpoint is set to –3.0 V and the data center is 0, the cantilever deflection axis of the graph centers around –3.0 V. Raising the setpoint to –2.0 V shifts the force calibration curve down by one volt so the graph centers at –2.0 V. Changing the value of this parameter also changes it in Image mode.

The RMS value of the cantilever deflection voltage maintained by the feedback loop in Image Mode can be adjusted by changing Amplitude setpointOperator-selected threshold used as the target of the feedback control loop.. In a TappingMode AFM force plot mode, the setpoint defines the centerline of the vertical, “Amplitude” axis of the amplitude calibration plot (the Data Center must be 0 for that Channel). Changing the Amplitude Setpoint shifts the amplitude curve on the graph. For example, if the setpoint is at 3.0 V, the RMS amplitude axis of the graph will be centered around 3.0 V; raising the setpoint to 4.0 V will shift the amplitude curve down by one volt, so the graph will be centered at 4.0 V. Changing the value of this parameter in the Amplitude Calibration mode also changes the setpoint parameter in Image mode.

This parameter changes the gain applied to the input signal. You can reduce the input signal to see more of the Force Calibration plot deflection or amplitude. This parameter also affects Image Mode and the resolution of the system; therefore, change the value back to the Image value before returning to imaging.

This parameter defines the frequency at which the cantilever is vibrated. This frequency should be close to the resonant frequency of the cantilever. Changing the value of this parameter in the Force Plot menu also changes the Drive Frequency parameter in the Image Mode.

This parameter defines the amplitude of the voltage applied to the piezo system which drives the cantilever vibration. Changing the value of this parameter in Force Plot mode also changes the Drive Amplitude parameter in the Image Mode.