Metrix GX1010 Notice De Fonctionnement page 104

signal peak is limited to ± 10V to avoid waveform clipping, a warning message will be
displayed. This is explained more fully in the Warnings and Error Messages section.
4.2.1.5. DC Output
The DC Offset control can be used to provide an adjustable DC output level if the
waveform is off; the recommended set-up is as follows:
Select GATE edit mode and set the SOURCE to MAN/REMOTE. Exit edit mode and turn
on GATE mode with the GATE key. Provided that GATE mode is not triggered, the MAIN
OUT will now remain at the level set by the DC Offset control.
On the main menu set the output level to 1Vpp; this ensures that the software does not
warn of clipping (output level too high) and that the output attenuator is not switched in
(which would also attenuate the DC Offset). With the cursor in the DC Offset field the
MAIN OUT can now be adjusted over the range ±10V EMF.
4.2.1.6. Symmetry
Pressing the SYMMETRY key moves the flashing edit cursor directly to the symmetry
numeric field on the bottom line of the display. This is the only field that can be edited; the
bracketed field on the right-hand side shows the actual symmetry which might differ from
that set if the set value is outside that permitted for the selected frequency and waveform
combination, see Specification section. For example, in the display below the frequency is
set to 100kHz and a squareware is selected.
The symmetry is set to 90% but the actual symmetry is 80%, the limit for squarewaves and
pulse waveforms above 30kHz.
The flashing cursor can be moved within the field using the DIGIT keys; turning the rotary
control will then increment or decrement the setting in steps determined by the position of
the cursor in the field.
Should the symmetry be set outside the permitted range for the selected frequency and
waveform combination a warning message will be shown on the display, see Warnings and
Error Messages section below.
4.2.1.7. Warning and Error Messages
Two classes of message are displayed on the screen when an illegal combination of
parameters is attempted.
WARNING messages are shown when the entered setting causes some change which the
user might not necessarily expect. Examples are:
1. Changing the EMF from 2.5Volts pk-pk to 250mV pk-pk brings in the step attenuator; if
a non-zero offset has been set then this will now be attenuated too. The message 'DC
OFFSET CHANGE BY OUTPUT LEVEL' will be shown temporarily on the screen but
the setting will be accepted; in this case the actual, attenuated, offset will be shown in
brackets to the right of the set value.
2. With the output level set to 10V pk-pk, increasing the DC offset beyond ± 5V will cause
the message 'DC OFFSET + LEVEL MAY CAUSE CLIPPING'. The offset change will be
accepted (producing a clipped waveform) and the user may then choose to change the
output level or the offset to produce a signal which is not clipped.
GX1010
FREQ=100.0000kHz
EMF=+20.0 Vpp
DC=+0.00mV (+0.00mV)
SYM=90.0% (80.0%)
50Ω Ω Ω Ω
II - 17