This thread reminded me to publish some old code to read the serial output of the Command Base and dump it to the console with human read-able text appended to the three hex byte command. The human read-able part - lots of #defines and text strings - was the grunt work. The last time I compiled this was on Visual Studio 6 many years ago. The current Visual Studio doesn't play nicely with old and "untrustworthy" C/C++ code (and life is too short to fuss with it) so building the executable is left to you. See the README for a link to the multi-threaded TTY I/O code for the files you'll need to build a Windows EXE. Of course, the Arduino folks will have to adapt the code appropriately for their platform, compilers, and I/O. The source is .cpp files, the code style is mostly C, so devolving classes to C should not be difficult.
GitHub project: CmdBaseReader
Command Base Reader example code
I'm currently using C# for development of Legacy tools so I cannot provide a Legacy version of CmdBaseReader using a C/C++ codebase. I'll publish a Legacy command monitor once I'm satisfied with the code.
Regarding the Command Base serial channel, there is no problem multi-dropping multiple devices that read the output (which is the environment of multiple ICControls devices). Don't know about potential chaos when transmitting to the Command Base from multiple sources. I only have one Action Recorder so I haven't stressed writing to the port.
With the LCS devices, each device connects to its neighbors via the PDI cable which is NOT multi-dropped, and I assume that the LCS firmware deals with serial line contention issues. Accordingly, I would recommend using the SER2 to transmit serial commands into the Legacy Base rather than connecting directly to the Legacy base.
Cheers,
John