#Java Command And Telemetry (JCAT) JCAT is a Java program created at the NASA Goddard Space Flight Center to aid in App development for the CFS (Core Flight System), a flight software product line used by multiple NASA centers. The CFS provides mission-independent, reusable, core flight software services and applications (Apps). Five of these Apps are contained in the cFE (Core Flight Executive).

Versions of the CFS are open-source and can run on platforms such as RTEMS virtual machines, embedded ColdFire processors, and, in the future, Raspberry Pi processors. Until now, however, there was not a ground system to allow a community of CFS developers to form. This is where JCAT comes in.

##What is JCAT? JCAT is the first open-source ground system for CFS App development. It is designed to be a lightweight, rapid-application prototype development program. JCAT accomplishes three tasks to aid in CFS App development: command-sending, telemetry-displaying, and event message-displaying. To test an App, developers simply need to connect JCAT to the CFS containing their App via Ethernet cable, router, or virtual machine, and load its App Profile into JCAT at run-time. JCAT can test any App in the CFS, whether or not it is in the cFE.

##What is an App Profile? An App Profile is an XML file that describes all the information JCAT needs to send commands to, and display telemetry from, an App running in the CFS. You must create or obtain an App Profile in order to use an App in JCAT. Examples of App Profiles are available in JCAT/App-Profiles/cFE-6.1/. To create an App Profile, you must first know its telemetry housekeeping packet and all its commands. Then, open the JCAT wiki's App Profile Creation Guide for further instructions.

##What JRE's does JCAT support? JCAT can run on Windows, Linux, and Macintosh on 32 and 64-bit JRE's of Java 6 or later, though it has been designed graphically for Windows.

##How do I get started using JCAT?

1. Determine your Java JRE, and select its corresponding JCAT release in JCAT/Executables/. Click 'View Raw', and save the resulting file to your hard drive.
2. Navigate to JCAT/App-Profiles/, open the folder for your cFE version, and download the files.
3. Navigate to JCAT/Constant-Definition-Files/, open the folder for your cFE version, and download the desired file.
4. Double-click the JCAT executable you downloaded in Step 1, and follow the in-program instructions. (for 64-bit Mac users to open JCAT, you must open Terminal, navigate to the location of JCAT, and type "java -XstartOnFirstThread -jar JCAT_osx64.jar").
5. To share your App and App Profile for community use, email [email protected] for instructions.

##How do I get started developing for JCAT?

1. Follow the directions in the JCAT wiki's Adding JCAT to Eclipse for JCAT Development.
2. To push changes to JCAT for community use, email [email protected] for permission to be added as a collaborator.

##What do I do if I need help? ######If you encounter a problem with JCAT, consult the following

1. JCAT in-program Help pages
2. JCAT repository wiki tab
3. JCAT repository Issues tab

#####If your problem is still not solved, you can add a New Issue to the JCAT repository Issues tab describing the problem or email our developers at [email protected].
######If you have questions, comments, or suggestions, don't hesitate to contact our developers at [email protected].