© ICSPI Corp. 2007-2021
nGauge AFM User Manual 2.0
59
PGAs
Programmable Gain Amplifiers (PGAs) are able to scale the voltages
output by the DACs. The PGAs are used to adjust the XY scan size,
the range of the Coarse and Fine Z, the amplitude of the AC driving
signal on the Z actuator, and the amount of leveling that is added to
each scan. PGA values can range from 0-140%.
The Z Fine PGA is the only setting that users may need to change. The
default value is 20.
Note
: do not change the
Z Fine DAC
. It is a
separate control from the
Z Fine PGA
.
ADCs
Analog to Digital Converters (ADCs) read analog voltages. Clicking
Read All
will display the current voltage level of the current sensing
circuits for X, Y, and Z, as well as the voltage levels of the amplitude
and phase measurement circuits. The ADCs range from 0-3.3V.
Resistances
Measured resistances of the MEMS actuators. Click the
Resistances
button to refresh measurements.
DDS
DDS (direct digital synthesis) section controls the drive signal
frequency. To set a new frequency, change both start and end
frequencies to the desired frequency.
Safety
Configurations
Encapsulates various safety features. Safety thresholds and features
may be modified or disabled in this section.
Approach Low Limit
specifies the low signal threshold that constitutes
a safe situation for auto-approach. If the measured signal at the
beginning of auto-approach is lower than the specified value, the
approach will be aborted. It is recommended to leave the setting at its
default value of 0.7 V.
Check Resistances
refers to the safety routine that is executed prior
to every
Sweep
,
Approach
, and
Scan
command. If enabled, the
software will measure resistances and check for any anomalies.
Limit Switch
refers to the end-stop mechanism to prevent motor from
driving the stage too low. In the unlikely circumstance that the switch is
damaged, and you cannot retract properly, you can uncheck the limit
switch feature to override the mechanism.
Updates
If an internet connection is available, this section shows if the software
and firmware used are up to date. If updates are available, please go
to
