The PScan2T SPM Controller

Our unique system combines the convenience of a WindowsT user interface with real-time control of microscope operations through an Ethernet connection. No more expensive DSP boards that may become obsolete tomorrow!

Because of its unique design, the PScan2T controller is ideally suited for developing advanced probe microscope instrumentation including atomic force, scanning tunneling and near field optical microscopes.
The PScan2T controller is appropriate for use by instrument companies that want to create their own scanning probe microscope products or as an add-on feature to an existing product.

The hardware in the PScan2T is designed for maximum speed and flexibility. All high voltage signals are isolated from digital signals for optimal low noise performance. Functions supported by the PScan2T controller include:

X-Y Raster:
Support is provided for tripod scanners with or without external linearization. Tube scanners can be controlled with the optional high voltage board.

Z Feedback:
A digitally controlled high speed analog PID controller optimizes the control of the Z feedback loop in all scanning probe instruments. Force/distance curves are also possible by disabling the Z feedback control.

Modulation:
An internal 32-bit sinusoidal function generator and amplitude detector are available for techniques such as non-contact FM and shear force NSOM measurements.

Sensor inputs:
Support is provided for 4 quadrant photo-detectors used in most AFM heads. Additionally, the sensor output from STM and NSOM heads can be directly input into the PScan2T controller.

Motor Controls:
For Z approach, both DC and stepper motor controllers are available. Additionally, seven stepper motor controllers are available for sample stages and other control functions.

Head Support:
Flags and control lines are available for turning lasers on and off in AFM heads and monitoring feedback signals.

Digitally Programmed Analog Output:
For creating new applications such as electrochemistry, two additional 12 bit analog outputs are provided.

Additional I/O Support:
Additional I/O support is available through a 16 bit TTL bus. This bus can be used for additional ADC or DAC's to the PScan2T controller.

From the ground up, the PScan2T controller was designed for maximum flexibility. Because of its unique design, the PScan2T controller offers high performance combined with high value. A few of the advanced features of the PScan2T controller are:

Master-Slave Design:
Communication between the master computer and the slave controller is through an industry standard Ethernet communications protocol and incorporates a Data-Command Exchange (DCExT) protocol for information transfer. Thus, the master computer may be PC, MAC or UNIX based. A PC WindowsT XP version of the master software is shipped with every unit. Furthermore, a single master unit can be used with many slaves. Proprietary Pacific Nanotechnology software permits real time control of parameters, including PID settings, scan range and scan speed.

Microprocessor Based Controller:
The sophisticated PScan2T electronic controller is based on a Pentium CPU and operates independently of the master computer. The controller has its own RAM, and a 2+ gigabyte hard drive for storing a high quantity of data. The high speed communications protocol allows the simultaneous X-Y positioning and acquisition of up to three high resolution images (1024 x 1024) at 20 kHz or four images at 16 kHz.

Flexibility:
Many types of Probe Microscope heads are easily controlled by the PScan2T. As an example, support is provided for tripod and tube scanners having external linearizers. Probe approach is achieved by stepping and DC motors. The controller comes standard with three high voltage amplifiers and with the high voltage upgrade board. Another five high voltage amplifiers can be added.

Expandable:
The PScan2T is the first ever control system designed for the direct control of more than one SPM head using a single master computer. Using the Ethernet connection, multiple heads may be controlled simultaneously. Many new types of scientific and inspection applications are possible for the first time with the PScan2T controller. For example, this architecture enables arrayed SPM design which is needed for next generation of quality control tools in semiconductor manufacturing.

The PScan2™ Controller communicates with the "master" computer through standard Ethernet protocols. An extensive software library is available for execution of the standard scan functions such as tip approach, scan, rotate, and zoom. A developer software package, SPMCockpit™, written in industry standard Visual Basic, is included with each PScan2™ controller. It provides basic SPM control features and the code can be used as a template for developing software for particular applications.