BNC 645 - Manual (Page 168)

168
load). If you specify an invalid voltage level, the waveform generator will adjust
it automatically to the highest allowed value and “Data out of range” error is
generated.
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The high voltage level should always be greater than the low level. If not,
a “Setting conflict” error is generated and the waveform generator
automatically set the high level to 1 mV larger than the specified low level.
z
specifying a high level and low level also sets the offset. For instance, you
will have an amplitude of 5 Vpp (with an associated offset voltage of -500
mV) when you set your high level to +2 Vpp and low level to -3 Vpp.
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When the Output Termination Setting is changed, the voltage levels are
automatically adjusted. For instance, when you change the output
termination from 50 ohms to “high impedance”, your voltage shown on the
display doubles, and when Output Termination has been changed from
“high impedance” to 50 ohms, the voltage decreases in half.
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To invert the waveform relative to the offset voltage, you can use the
OUTP:POL command.
VOLTage:LOW? [MINimum︱MAXimum]
Query the low voltage level.
VOLTage: RANGe:AUTO{OFF︱ON︱ONCE}
Disable or enable the voltage auto-ranging. The default is “On” where the
waveform generator selects an optimal setting for the output amplifier and
attenuators. When the auto-ranging is “Off”, the current setting is used.
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The “ONCE” parameter enables the auto-ranging, selects an optimal
setting and then disables it.
z
The APPLY command overrides this command and turns the auto-ranging
on.
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Disabling the auto-ranging can avoid momentary disruption caused by
attenuators switching while changing amplitudes. However, the amplitude
and offset accuracy may be adversely affected when reducing the
amplitude below the expected range change.
VOLTage: RANGe:AUTO?
“0” (off) or “1” (on) indicating the auto-ranging enable state is returned.