R e m o t e c o n t r o l
more than one command at a time. On reception
of terminator <CR>, the equipment sends the
character 19 (<DC3> ASCII) to indicate that the
dialogue is suspended. As soon as it is possible to
resume dialogue, the instrument sends character
17 (<DC1> ASCII). The commands are divided into
fi ve groups:
Function commands
These commands are used for choosing another
magnitude to be measured and corresponding to
the choice of FUNCTION key on the front panel.
VO<CR> voltage measurement (VOLT)
AM<CR> current measurement (A)
MA<CR> current measurement (mA)
OH<CR> resistance measurement
DI<CR> diode test
TC<CR> temperature measurement in °C
TF<CR> temperature measurement in °F
DB<CR> measurement in dB.
For these commands, there is no error recovery
provided for because it is normally possible to put
the instrument in one of these states at any time.
Mode commands
Mode commands correspond to the "MODE" key
on the front panel.
DC<CR> switches the instrument to the
DC measuring mode.
AC<CR> switches the instrument to the
AC measuring mode.
AD<CR> switches the instrument to the
AC + DC measuring mode.
BY<CR> activates the continuity test beep.
BN<CR> deactivates the continuity test beep.
If the requested mode is not compatible with the
current function (e.g.: sending the AC command
while the instrument is measuring resistances),
the instrument will indicate this by a beep in
the same way as for the front panel control. In
addition, the control error indicator is set (see
command E?).
Range modifi cation commands
These correspond to the "RANGE" keys on the
front panel.
AY<CR> switches to automatic range change
AN<CR> switches to manual range change
30
Subject to change without notice
R+ <CR> switches to the next higher range
R– <CR> switches to the next lower range.
If it is impossible to activate or deactivate the au-
toranging the current function (e.g. following the
AM command to switch to current measurement
the AY command cannot be executed since the
measurement is made in a single range for this
function) or if it is impossible to change ranges,
the instrument will send a beep. In addition, the
command error indicator is then set (see com-
mand E?).
Display type commands
These correspond to the choice of the HOLD
OFFSET key on the front panel.
HD<CR> switches the instrument to HOLD
O1 <CR> switches the instrument to OFFSET
(Single)
O0<CR> switches the instrument to NORMAL
L0<CR> locks the front panel. In this case,
pressing a front panel key will cause
the "rtEOn" message to appear.
L1<CR> is a way of unlocking the front panel.
The NORMAL type corresponds to a display with-
out a reference (OFFSET) and without maintaining
(HOLD) the front panel state. In the same way as
for the manual control, it is impossible to switch to
the OFFSET mode without fi rst going to the HOLD
mode. Indeed, the maintained measurement is
used as a reference.
The possible steps are therefore:
NORMAL (HD) → HOLD (O1) → OFFSET (HD) →
OFFSET + HOLD (O0) → NORMAL
Unlike the manual command, it is possible to
return directly to the NORMAL mode at any time
during command O0.
Status commands
The status commands are used for recovering
the status of the instrument. The returned infor-
mation consists of ASCII character strings, each
terminating in a <CR>.
I? <CR> Request for equipment identifi cation
which returns:
HAMEG, HM8012, V1.03<CR>
I.e.: manufacturer, instrument