Both axes are microprocessor-controlled and due to this remote operation ability over the serial port is possible.The CCD cameras used during the experimental phase is a Quickcam.
It accepts commands from the end user through a Web browser and returns an HTML document based on the end user's input. A Web browser calls this CGI application through the HTTP server that is running on the server computer with the TCP/IP (Transmission Control Protocol/Internet Protocol) address 131.2. The parameter string is decoded and the command : Mn# (move north) is sent to the telescope over the serial port.CGIs have a standard API (Application Programming Interface) for receiving a response from a remote user and taking action such as checking an end-user name and password against a valid user list, returning a different HTML (Hyper Text Markup Language) page to the user, making a computation and returning the results, or dynamically building an HTML page based on the data passed.On the World Wide Web (WWW), when a client sends a request whose URL (Universal Resource Locator) specifies a CGI application, the server decodes the request, loads the application, and executes the application.In figure 4 an example is shown where Lab VIEW HTTP server using the TCP/IP port 80 and Webcam HTTP server using TCP/IP port 81 are both running on the server computer.The number of server software packages running on the server (the complexity of the system) can be hidden to the end user.The server computer is a standard PC: in our case a Pentium-II 233 MHz with a T1/Ethernet Internet connection at Portland State University.
The telescope is connected to the server computer over the serial port (RS-232).
Several other languages are available and they might be used instead.
In Lab VIEW, applications called virtual instruments (VI) can be written which provides signal processing to control your hardware.
This software package (Webcam) uses different methods of controlling and requesting images over the WWW. The location of the image is implemented in the response from the telescope CGI application and the latest image gets loaded to the Web browser.
Second the software is setup as an additional HTTP server on the server computer.
The application generates data and returns it to the server.