DecoderScript Overview
The DecoderScript™ Reference Manual and User Guide is delivered with each Frontline ComProbe® Protocol Analysis System installation package under Developer Tools. The manual is also available on-line at FTE.com.
The main purpose of this manual is to describe DecoderScript™, the language used in writing decoders. DecoderScript allows you to create new decoders or modify existing decoders to expand the functionality of your ComProbe protocol analyzer. DecoderScript displays protocol data, checks the values of fields, validates checksums, converts and combines field values for convenient presentation. Decoders can also be augmented with custom C++-coded functions, called "methods", to extend data formatting, validation, transformations, and so on.
A decoder defines field-by-field how a protocol message can be taken apart and displayed. The core of each "decoder" is a program that defines how the protocol data is broken up into fields and displayed in the Frame Display window of the analyzer software.
This manual provides instruction on how to create and use custom decoders. When reading the manual for the first time, we encourage you to read the chapters in sequence. The chapters are organized in such a way to introduce you to DecoderScript writing step- by- step.
Screenshots of the ComProbe protocol analyzer have been included in the manual to illustrate what you see on your own screen as you develop decoders. But you should be aware for various reasons, the examples may be slightly different from the ones that you create. The differences could be the result of configuration differences or because you are running a newer version of the program. Do not worry if an icon seems to be missing, a font is different, or even if the entire color scheme appears to have changed. The examples are still valid.
Examples of decoders, methods, and frame recognizers are included in this manual. You can cut and paste from these examples to create your own decoders.
A quick note here: Usually the pasted code appears the same as the original in your editor. Some editors, however, change the appearance of the text when it is pasted (something to do with whether it is ASCII or Unicode text). If you find that the pasted text does not appear the same as the original, you can transfer the code into a simple text editor like Notepad, save it as an ANSI (ASCII) file, then use it in your decoder.
These files are installed in the FTE directory of the system Common Files directory. The readme file in the root directory of the protocol analyzer installation contains a complete list of included files. Most files are located in My Decoders and My Methods.
We will be updating our web site with new and updated utilities, etc, on a regular basis and we urge decoder writers to check there occasionally.