1.3.2 Network installation

Here at Northwestern, Cogsys is run in a networked environment. This allows a clean separation between the data host and the Cogsys client system. The data host is the computer that is used to store both the teslists and outfile, and that is probably used to both create those teslists and analyze the data files. Such a machine is probably a workstation running some variant of the Unix operating system. By contrast, the Cogsys client system need only be a very low end DOS box which is probably used for nothing other than running testlists.

The idea behind a networked installation is to have several (here, we have 9) client machines that are all connected to one data host. A control program runs on the client system. The control program asks for testlist and outfile names; it then retrieves the testlist from the data host, runs Cogsys, and then uploads the outfile to the data host, and starts over.

There are some important things to remember when using a networked installation:

• Cogsys does does not, and should not, know about the control program. Cogsys will simply run whatever file it was told to run. When a networked installation has a problem, the first thing to determine is whether the fault is with Cogsys or the control program.
• Similarly, Cogsys writes its data to the output file that was specified. It is the control program's responsibility to properly archive or upload the contents of this file. Particularly if Cogsys is run in succession without explicit outfile specifications, it will simply overwrite the old data.
• If possible, all of the client systems should be identical. This greatly reduces problems that are caused by oddball hardware (say, a strange video card or BIOS).

1.3.2.1 Serial Connection
1.3.2.2 Ethernet Connection