Ectron 441A, Instructions Manual, Page: 21 / 74

the screens that the user would typically access while
operating the Model 441A. The other is to press and
hold the display for more than one second. This evokes
a set of secondary screens to set parameters less
frequently changed.
Encoder
The round encoder has the dual function of character
selection and control. Once a screen has been selected,
a blinking cursor will appear that will cover one or
more characters. The cursor always first appears on the
top left-most character. Pressing the encoder moves the
cursor across the screen and down through all the
changeable characters and back to the top left. If the
user inadvertently steps past the character to be changed,
simply continue pressing the encoder until the cursor is
where he or she wants it to be.
Once the character to change has been selected, rotate
the encoder either clockwise or counterclockwise until
the character is correct. When changing numbers, ro-
tating the encoder can change digits to either side of
the digit being changed. For example, if the user is
changing one of the voltage set points, and the cursor
is on the tenths digit, then changing it from 9 to 0 will
increment the ones digit. The user should remember
that the Model 441A screen values will not violate the
limits shown in Table 3-2. If he or she is rotating the
encoder and the character under the cursor is not chang-
ing as expected, the most likely cause is that the
Model 441A is being asked to exceed a limit.
The encoder has two additional functions when the user
wants to reset the default parameters. When at the screen
to align
+
10 V, pressing and holding the encoder for
more than one second evokes the
RESET
screen, which
gives the user the opportunity to perform a reset. If the
user then chooses
Y
es and presses the encoder, a reset
is performed.
Once a character has been changed, and the operate
screen restored, the nonvolatile memory is updated with
the new information. However, if power is interrupted
between the time of character change and return to the
OPERATE
screen, memory is not updated.
Model 441A Operation
3-5