Hameg R&S HM8118 Benutzerhandbuch Seite 69

you can use the NAVG command to select the number of
measurement values to be used for the calculation of the
average. The AVGM? query queries the status of the calcu-
lation of the average.
NAVG(?) {i}
If you use the AVGM command to set the calculation of
the average to i=1, you can use the NAVG command to set
the number of measurement values to be used for the cal-
culation of the average anywhere between 2 and 99.
The NAVG? query queries the number of measurement va-
lues to be used for the calculation of the average.
The constant voltage (CST V function) must be switched on for
measurements with bias current or external preload.
VBIA(?) {x}
The VBIA command sets one internal DC preload any-
where between 0V and 5V. This command returns an error
message (ERROR) if the HM8118 is not set to a measure-
ment mode C-D, C-R, R-X or Z-Θ which would be suitable
for a preload. Use the BIAS 1 (= internal) command to ac-
tivate the preload which was previously activated via VBIA
and to show it on the display. The VBIA? query queries the
current value of the applied DC preload.
IBIA(?) {x}
The IBIA command defines the DC bias current between
0.001A and 0.200A. This command returns an error mes-
sage (ERROR) if the HM8118 is not set to perform an in-
ductance measurement or a transformer measurement (L-
Q, L-R, N-Θ or M). Use the BIAS 1 (= internal) command
to activate the bias current which was previously activa-
ted via IBIA and to show it on the display. The IBIA? query
queries the current DC bias current.
The error message "DCR too high" indicates that the resistance
of the connected DUT is too high for the selected bias current. In
this case, the bias current cannot be activated.
BIAS(?) {i}
The BIAS command activates or deactivates the DC pre-
load or DC bias current defined in the HM8118. Use i=0
to deactivate the DC preload that is selected via VBIA, or
deactivate the DC bias current that is selected via IBIA.
Use i=1 to activate the internal BIAS and to show the va-
lue that was previously selected via VBIA or IBIA on the
display. Use i=2 to select the external BIAS which is only
possible with a DC preload. The internal BIAS preload can
only be selected if the instrument is set to the appropri-
ate measurement function (see VBIA command). The in-
ternal BIAS bias current can only be selected if the instru-
ment is set to the appropriate measurement function (see
IBIA command). The external BIAS function behaves cor-
respondingly. The BIAS? query queries the current BIAS
status.
CIRC(?) {i}
Use the CIRC command to select the circuit type of the
equivalent circuit diagram (measurement circuit). By de-
fault, the automatic circuit type (i=2) is selected. Use i=0
to set the series circuit, use i=1 to set the parallel circuit
of the equivalent circuit diagram. The CIRC? query queries
the current status of the equivalent circuit diagram setting.
CONV(?) {i}
The CONV command activates (i=1) or deactivates (i=0)
the constant voltage (function CST V). The CONV? query
queries the current status of the constant voltage.
FREQ(?) {x}
Use the FREQ command to select the measurement fre-
quency in Hz. The 69 available measurement frequency in-
tervals are as follows:
Measurement Frequencies
20Hz 90Hz 500Hz
24Hz 100Hz 600Hz
25Hz 120Hz 720Hz
30Hz 150Hz 750Hz
36Hz 180Hz 800Hz
40Hz 200Hz 900Hz
45Hz 240Hz 1.0kHz
50Hz 250Hz 1.2kHz
60Hz 300Hz 1.5kHz
72Hz 360Hz 1.8kHz
75Hz 400Hz 2.0kHz
80Hz 450Hz 2.4kHz
The FREQ? query queries the set measurement frequency
in Hz.
MMOD(?) {i}
Use the MMOD command to select the trigger type. Use
i=0 to select the continuous trigger, i.e. a new measure-
ment will automatically be performed upon completion of
the previous measurement. Use i=1 to select the manual
trigger (TGM). In this case, a measurement will be perfor-
med only after the *TRG command was sent. Use i=2 to
select the external trigger (TGE). A measurement is perfor-
med when a rising slope is applied to the external trigger
input (TTL level +5V). The MMOD? query queries the cur-
rent status of the triggering.
If the measuring instrument shows a blank screen (i.e. lines "- -
-") without measurement values, no trigger event / measurement
has been triggered or the selected measurement function has
been selected incorrectly.
*TRG / STRT
Use the *TRG or STRT command to start a measurement
if the manual trigger mode was previously selected (see
MMOD).
RATE(?) {i}
Use the RATE command to set the measurement speed
(SPD function) in the increments FAST (i=0), MED (i=1)
or SLOW (i=2). The number of measurements for a con-
Command Reference
2.5kHz 12kHz 72kHz
3.0kHz 15kHz 75kHz
3.6kHz 18kHz 80kHz
4.0kHz 20kHz 90kHz
4.5kHz 24kHz 100kHz
5.0kHz 25kHz 120kHz
6.0kHz 30kHz 150kHz
7.2kHz 36kHz 180kHz
7.5kHz 40kHz 200kHz
8.0kHz 45kHz
9.0kHz 50kHz
10kHz 60kHz
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