Bit 1 = SET→PPM selected, CLEAR→MG/M3
Bit 0 = reserved (LSB)
DSPAN
Function: Commands the instrument to enter span mode.
Format: DSPAN, {<DEVICE I.D.>} {TERMINATOR}
Device response: <ACK> if the instrument is able to perform the command, <NAK> if not.
DZERO
Function: Commands the instrument to enter the zero mode.
Format: DZERO, {<DEVICE I.D.>} {TERMINATOR}
Device response: <ACK> if the instrument is able to perform the command, <NAK> if not.
ABORT
Function: Commands the instrument to abort the current span/zero mode and
return to measure mode.
Format: ABORT, {<DEVICE I.D.>} {TERMINATOR}
Device response: <ACK> if the instrument is able to perform the command, <NAK> if not.
RESET
Function: Reboots the instrument (software reset).
Format: RESET, {<DEVICE I.D.>} {TERMINATOR}
Device response: <ACK>.