the bluetooth is a virtual serial, pin 1234, 9600 baud, 8 data bits, 1 stop bit
the following list of commands work
*Query commands are post-fixed with a "?"
*For queries regarding the secondary display, append @2 to the command (e.g. CONF? @2)
*IDN? - Identification
SYST:BATT? - Request batter status. Not sure what units are returned.
CONF? - Request confirguration (e.g. "VOLT:AC +5.00000000E+00,+1.00000000E-04")
STAT? - Request unit status. I have not decoded the meaning of the return value for this. (e.g. "000000I00302L00004001")
FETC? - Request current reading (and FETC? @2 returns current reading on secondary display)
*RST - Meter reset
SYST:VERS? - Unknown, my meter returns 1990.0
SYST:ERR? - Unknown, probably returns the last error
READ? - Request current reading. I don't believe that the @2 option works for this command.
If your meter supports logging (manual or auto) then the following commands can be used:
LOG:AUTO xx - Request value of auto-log position xx
LOG:HAND xx - Request value of manual log position xx