Hach 8450, Instrument Manual

Page: 31 / 66

Section 3
Page 31
16116Operation.fm
Initial Power-Up and Self Test
2. Place another magnet over the
Up
arrow icon to increase the contrast or
over the
Down
arrow icon to decrease it.
3. When the display has the desired contrast, remove the magnets in
reverse order.
3.7 Initial Power-Up and Self Test
Series 8400 monitors feature a convenient method of viewing and changing
system parameters. Upon initial power-up, the unit performs a self test on
both the LCD and front panel LEDs. All LCD character locations should be
visible and LEDs illuminated for about 2 seconds. The Sigma copyright
screen, which also shows the monitor’s software version, is displayed,
followed by the Main Screen (see
Figure 20 ).
To perform a system self-test after the system has been powered-up and is in
the Main Display, place the magnet over the icon. The self test verifies all LCD
segments (on/off) and system, serial number, and software revision.
3.7.1 *Check* Messages
Whenever system faults are detected, the Check LED will be illuminated and
the Main Screen will scroll a check message indicating the nature of the
problem (see
section 4.7 on page 59 ). To view the Main Screen, use the
magnet and select any of the front panel icons.
Alarm 1 and Alarm 2 are automatically cleared and inhibited in the presence
of certain CHECK alarms. If Alarm 1 or Alarm 2 is already active during these
alarms, its state is cleared. VMA analog outputs are held at the last reading
during system “Check.” A check screen example is depicted in
Figure 22 .
Figure 22 Scrolling Check Message
3.7.2 Inhibiting Messages
Particularly when the user is attempting to become familiar with the operation
of the front-panel controls and displays, it is helpful to inhibit scrolling
messages that may occur when the meter is first powered on.
Until the meter is calibrated with the probe supplied, an out-of-calibration
scrolling message will appear. For the purpose of familiarization with the
menus and controls without doing an immediate calibration, it is possible to
inhibit the scrolling message. Navigate through the menus using the magnet
and icons as described above. The menu sequence for inhibiting a CHECK
alarm is as follows: Main Menu, > ALM, > CHECK, lfit. In the lfit display,
change the bit under the (i) parameter from a 0 to a 1 (inhibit enabled).
*CHECK*
Scrolling message...