The Cascade TextLogger is normally used with a configuration file called, for example, textlog/tl.cfg. A sample configuration file appears in the Example section at the end of this chapter.

A configuration file is useful for sending initial start-up commands or specifying global defaults. These might include time, timestamp, and usegmt that control the expression of time; or collect and tolerance that control how data is associated.

The syntax for configuration commands is based on Lisp syntax. It consists of the name of the command, followed by a space-separated list of arguments, all enclosed in parentheses, like this:

(command arg1 arg2 arg3 ...)

These commands are commonly written one per line for clarity, but it is not necessary to do so. Any number of commands can be written on a line. Also, if a command becomes very long, it is possible to break it up into several shorter lines with line breaks to make the configuration file more readable. In either case, the parentheses are what delimit the command.

Comments are denoted by a semicolon (;) at the beginning of each comment line. For example:

; This line is a comment.
; The following command will not be executed:
; (usegmt t)
; The following command will be executed:
(collect fill)