BNC 645 - Manual (Page 101)

101
The waveform generator has adjusted the pulse width to a greater
minimum determined by the current period.
-221 Settings conflict; edge time decreased due to pulse width
The waveform generator adjusts first the edge time then the pulse
width or duty cycle, then period if needed to accommodate the
following the limitation: EdgeTime ≤ 0.625 x PulseWidth. In this case,
the edge time is decreased by the waveform generator to
accommodate the specified pulse width.
-221 Settings conflict; edge time decreased due to pulse duty
cycle
The waveform generator adjusts first the edge time then the pulse
width or duty cycle, the period if needed to accommodate the
following the limitation: EdgeTime ≤ 0.625 x Period x DutyCycle. In
this case, the edge time is decreased by the waveform generator to
accommodate the pulse duty cycle.
-221 Settings conflict; amplitude changed due to function
When the new function chosen has a smaller maximum amplitude,
the waveform generator will automatically adjust the amplitude from
the old value to the new smaller maximum value. This may occur
when the output units are Vrms or dBm due to the differences in crest
factor for the various output functions.
-221 Settings conflict; offset changed on exit from dc function
In the dc voltage function, the voltage level is controlled by adjusting
the offset voltage (the current amplitude is ignored). When you select
a different function, the waveform generator will adjust the offset
voltage as needed to be compatible with the current amplitude
setting.
-221 Settings conflict; FM deviation cannot exceed carrier
The frequency deviation cannot exceed the carrier frequency, or the
waveform generator will adjust the deviation to a maximum allowed
value.