Because turning V-Span on will always change the output voltage, it can only be enabled or
cancelled with the output off. If attempts are made to enable or cancel V-Span with the output on,
the display will briefly show the message
To set new values for V
min
The lower voltage limit is defined by using the MAIN and FINE VOLTAGE controls to set exactly
the required value; the V
flashing and the right-hand side (mA) display shows
time by a short press (<1 second) of the V
exactly the same way using the VOLTAGE controls and the V
The limits can be set in any order and to any value within the output range of the instrument but
V-Span can only be turned on with the ENABLE key if V
met, the message
Set Err
When V-Span is enabled, the range of the MAIN VOLTAGE control is exactly V
the FINE control is set at its mid-point, marked on the panel with a • . The FINE control itself
can be usefully used to give an additional fine adjustment of ±1% (of the voltage span).
The V-Span status at power on is the same as at last power off.
Mode Control of the Quad-Mode Dual
However, it is not possible to guarantee that there will never be any unwanted transients as the
mode is switched and the recommendation is therefore that both outputs should always be
switched off before any mode change.
Independent
Set the MODE switch to INDEPENDENT. The two outputs are completely independent and
electrically isolated; each can be set as described in the preceding Output Control section.
It is not possible to switch from Independent mode to Tracking with LOCK set on the Slave
output. The message
Un loc
off (in Independent mode) before the Tracking modes can be used.
See also the Retained Slave Settings paragraph.
Isolated Tracking
Set the MODE switch to ISOLATED TRACKING. The two outputs remain electrically isolated but
the Voltage controls of the Master output set an identical voltage on the Slave output. The
V-Span is turned on or off with the ENABLE key. The
ENABLE lamp is lit when V-Span is selected. The
factory default is V
to prompt the user to turn the output off.
turn oFF
or V
the V-Span function must be off (cancelled).
max
key is then held pressed until the left-hand side (V) display stops
min
Set
key. The upper voltage limit is set and VIEWed in
min
max
is briefly displayed and the V-Span function is not implemented.
The four operating modes of the Quad-Mode Dual are
described below; the mode is changed using the MODE
rotary switch. To prevent unintended voltages being
accidentally applied to the circuits connected to the outputs,
changing modes will always cause both outputs to be
switched off.
is shown in the Slave display and LOCK must first be switched
= 3V, V
= 5V
min
max
. The setting can be VIEWed at any
key.
max
≥ (V
+ 0.1V); if this condition is not
min
to V
min
max
when
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