There are three separate-but-joined pieces involved in communicating with this machine:

Network

Configured by the Lantronix telnet or web interface; admittedly, you have to find it, first.

Baud Rate

Everybody has to agree on baud rate or bad things happen. Moreover, the SAS board is sufficiently opinionated that it will only speak 115200, so that means that everybody else has to fall in line!

Power

Ah, my favorite. Telnet in, send Ctrl-^, and P will toggle the power of the SAS board and disks.

Console

The enclosure command will tell you about the box itself, including the internal PSU, fan, and temperature sensors, which might be fun to scrape for logging and alerting.