Heater/Cooler Software Control

If you have a NanoScope V Controller and NanoScope 7.30 or later software, the Thermal Applications Controller can be controlled using the NanoScope software, as described below. Earlier NanoScope or NanoDrive software requires front panel control, discussed in TAC Panel Control.

Configure the NanoScope Software

1. Launch the NanoScope software by clicking on the desktop microscope icon.
2. Set the microscope configuration by selecting Tools > Select Microscope... to open the Microscope Select window:

3. Click the Edit button to open the Equipment window, then click the Advanced button to show all the equipment options:

4. Select the TAC Controller in the Temp Controller field:

5. Click OK to apply this selection.
6. Configure the serial ports by clicking the Serial... button in the Microscope Select window. This will open the Serial Port Configuration window:

7. Highlight appropriate port and click the Edit button to open the Edit Port Setup window:

8. Use the drop-down menu to select TAC Temp Control in the Equipment Type field and click OK to close the Edit Port Setup window for that port.
9. Click Done to close the Serial Port Configuration window.
10. Click OK to close the Microscope Select window.

Software Control

Sample and tip heater temperatures can be controlled through the Temperature Control panel, available in either the Scan view:

Temp Panel Parameters:

• TAC Status:
  • Status of the TAC Controller; identifies stage type, errors.
  • Settings: Heat Stage/TE Stage
• Temp Stage Setpoint:
  • User choice
  • Range:
    • 0°C to 250°C (Heat Stage)
      
    • –40°C to 100°C (TE Stage)
  • Default Setting: 25°C
• Tip Heater Mode
  • Settings: Auto/Manual
  • Default Setting: Auto
• Tip Heater Voltage
  • Range: 0 V to 20 V
• PID Mode
  • Settings: Air/Fluid
  NOTE: The only heater/cooler element with fluid capability is the Heating and Cooling Elements (Bio Heater), which is only available for MultiMode SPMs. For all other SPMs, the PID Mode parameter will be automatically set to "Air" and grayed out.
• Temp Stage Power
  • Settings: Disabled/Enabled
  • Default Setting: Disabled
• Auto Z-Step
  • Specifies if auto z-stepping function is active (enable). If the NanoScope software detects that the z-scanner is nearly out of range (perhaps from thermal drift) and auto z-step is enabled, the step motor will reposition the scanner.
  • Settings: Disabled/Enabled
  • Default Setting: Disabled
• Stage Temperature
  • Reports the stage temperature measured by the thermocouple.
• Base Temperature
  • Reports the base temperature measured by the thermocouple.
• Temp Stage Current
  • Reports the output current of the TAC.
  • Range:
    • 0 mA to 650 mA Heater stage
    • 0 mA to 1350 mA Thermoelectric cooling stage

Auto Z-Stepper Motor Control

Z-drift can be a significant problem for heating (and cooling) due to thermal expansion. The purpose of the Auto Z-Step function is to keep the Z-center position from becoming extended or retracted, as a result of z-drift.

To activate Auto Z-Step:

1. Engage on the sample.
2. In the Temperature Control parameter list, change the Auto Z-Step parameter to Enabled. The Auto Step Motor window will appear.
3. Configure the Auto Step Motor and click the Start button.
4. To turn off the Auto Step Motor function, click the Stop button.

With Auto Z-Step enabled in the Temperature Control panel and started via the window, NanoScope software automatically steps the z-stage up or down whenever the z-center voltage drifts too far towards the fully retracted or fully extended position. These two z-positions are user defined by Retracted Threshold and Extended Threshold, shown in Figure 1. When the z-center voltage is less than Retracted Threshold, then the z-stage is stepped "up" (by the Motor Step Size) until the z-center is at the Target Z-Center.

The Withdraw Threshold, for the retracted side only, protects against feedback errors, which cause the Z piezo to fully retract. If the Z-center is less than the Retracted Threshold, the probe is automatically withdrawn.

Figure 1: Auto Step Motor window

Auto Z-Step logic is shown in Figure 2 with the Auto Step Motor functions and symbols defined below.

Figure 2: Auto Z-Step logic

Table 1: Parameters and Setting Ranges and Defaults for the Auto Step Motor Window

Short Withdraw

The purpose of the short withdraw function is to provide you with a safe means to change temperature, adjust the detector and feedback settings, tune the cantilever tune, etc. in close proximity to the surface so that the temperature of the tip and sample remain stable and the gas seal is maintained.

The Short Withdraw function is available only when the tip is engaged on the sample surface. To execute a Short Withdraw, select Microscope > Short Withdraw from the NanoScope menu.

To change the short withdraw distance (the factory default is 20 μm):

1. Click Microscope > Engage Settings to open the Engage Parameters window:

Figure 3: Engage Parameters window

2. Modify the Short withdraw distance (range is 0 to 999 μm). The distance should be large enough to get off the sample surface but close enough to maintain a consistent temperature. Values between 20 and 50 μm are suggested.
3. Click OK.

Gain Reset

Due to the additional mass of the Heater/Cooler TappingMode Probe Holder, some systems may oscillate following engage. In this situation, the software will automatically reset the x and y integral gain values to protect the scanner. An error log dialog window will appear to inform the user. See Closed Loop XY Calibration for more information.

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