13
Manual Operation – Independent Mode
New users should first read the Initial Operation chapter which describes the operating principles
of the keypad and rotary jog control.
The default mode at power-up is ‘Tracking Off’, i.e. the two outputs are fully independent. The
following sections describe operation of either output in this mode. See the later ‘Manual
Operation – Link Menu’ chapter for details of the various tracking modes that can be set.
Set Voltage Range
There are two voltage ranges for each output – a low range (0 to 60V) and a high range (0 to 80V).
To select the range press SHIFT followed by RANGE. Changing to the higher range is always
possible and the display will show
Select 0 to 80V range: 2mV resolution. OK to
confirm, ESC to cancel;
pressing OK accepts the change. Because the resolution of the
80V range is 2mV the set-point will rounded down, if necessary, to the nearest 2mV figure (e.g. if
output is set to 59.997 it will be changed to 59.996).
When changing to the low range the display will show
Select 0 to 60V range: 1mV
resolution. OK to confirm, ESC to cancel
unless the output is set above 60V in which
case the display will show
C
an’t select 0 to 60V range. Set point too high. Esc
to cancel.
The output must first be set to <60V before the low range can be selected.
Set Voltage
With the
output off, the standard status display shows the set voltage;
Limits
shows as a
reminder beside
OFF
in the top line of the display. With the output ON the mode changes to
CV
(constant voltage) or
CI
(constant current), depending on the set current limit and load conditions,
and the display shows the actual output voltage (measured at the sense point); note that in CI
mode the actual output voltage will be less than the set voltage. Both the set and actual voltage
are shown to a resolution of 1mV (0-60V range) or 2mV (0-80V range). If the set voltage and load
conditions cause the instrument to operate outside its guaranteed power range the display will
show
UNREG
(unregulated) and the actual output voltage will again be less than the set voltage.
The voltage can be set directly from the numeric keypad: press the NUMERIC SET V key, enter
the new value using the numeric keys and confirm by pressing OK. The broad principles of
keypad entry are explained in the Initial Operation chapter, which should be read by new users.
When SET V is pressed the VOLTS display changes to show the present set value in a smaller
font, with the message
Enter V or ESC
below it, and the OK lamp starts flashing. The new
voltage is then entered from the keyboard, e.g. 12·345V is entered as 1, 2,
·
, 3, 4, 5. As it is
entered it is displayed directly below the present setting, replacing the prompt message.
The minimum voltage setting is 0·000V; the maximum setting is 60·000V (0-60V range) or 80.000V
(0-80V range).
Pressing OK at any point will set the voltage entered with any remaining digits set to zero,
e.g. 1, 2,
·
, 3, OK will set 12·300V; 1, OK will set 1·000V. When OK is pressed the set voltage is
changed and the display reverts to the standard status mode.
Pressing ESCAPE at any time during the sequence, or making no further key press within
10 seconds of the previous one will cause the display to return to its original reading before
SET V was pressed.
Entering a voltage outside the range maximum (including trying to enter 3 digits before the decimal
point) or trying to enter more than 5 digits will cause the buzzer to beep; the last key entry will be
ignored.
The voltage can also be set using the Jog control. Pressing JOG SET V will illuminate the V JOG
SET lamp and the VOLTS display will again change to two lines. With the output ON the top line
continues to show the actual output, but the additional lower display now shows the present
Limits
value; in the lower display, the JOG indicator ( ) is positioned under the digit that was last
jogged. Whilst the V SET lamp is lit, each further press will move the JOG indicator one digit to
the left; the selection 'wraps round' such that when the largest value of jog increment has been
reached the next press returns it to the lowest.
