Our experience with the development of the TEM project has shown the necessity for incorporating automation and intelligent algorithms into the data acquisition system. To effectively develop such a system requires a distributed hardware and software environment. The basic architecture of the Leginon system is illustrated in fig. 6. The components of the system are:
Instrument interface: To develop an instrument interface requires information from the manufacture and distributed control is needed for accessing the instrument over a network. This process is complicated by the lack of open systems and industry standards. Ideally the instrument should require minimal human interaction during an automated experiment. For example, the time between refilling cryogens on the TEM should be extended to support overnight runs.
Database: It has become clear in the course of the Leginon project that there is a critical need for a database to support the thousands of images that are acquired and the acquisition parameter data that is associated with each image. Incorporation of a database would provide improved data management as well as the ability to track acquisition, control, processing and modeling parameters.
Processing and analysis: Developing intelligent image acquisition systems requires that the instrument is closely integrated with processing and analysis software packages. There is a need for integration with commercial and community software packages and these need to support the interfaces for distributed access.
Control: A distributed control program must effectively synchronize all of the components of the distributed system and needs to be adaptable to each experiment. Ideally, the control program should be portable between systems and extensible by the end user.
User interface: The user interface must be flexible and suit the needs of the user. The system must be flexible enough to support new technologies like next generation web interfaces and virtual reality.
Additional features that would be desirable for use in the world wide laboratory include audio and video conferencing and real-time updates of the system status. These extra capabilities enhance the remote researcher's understanding of the current status of the instrument. We also believe that scheduling and security considerations are not only desirable but essential for turning this technology into a practical reality.