I just uploaded some Python code from a project I was working on a few years ago with the ErosTek ET-312B. I figured someone on here might find it useful. Read the comments in estimlib.py for more information.
Uses Python 2.7 and PySerial
CAUTION: Changing the mode causes the volume level on both channels to go to maximum! If anyone has any ideas on how to fix this, that would be great!