45
44
The colon is a useful indicator for the correct position of
squares.
Note
A maximum of two keys may be pressed simultaneously to be
properly recognized.
To exit the keyboard test procedure press LCD, CAL and SETUP
simultaneously.
EEPROM SELFTEST
The EEPROM selftest procedure involves verifying the stored
EEPROM checksum. If the checksum is correct the “Stored
data good” message will be shown for a few seconds before
exiting selftest procedure.
If not, the message “Stored data error - Press to reset
stored data or to ignore”.
If
is pressed the EEPROM selftest procedure terminates
with no other action. Otherwise, EEPROM is reset with de-
fault values from ROM as when a device with a virgin
EEPROM is switched on.
During EEPROM reset a blinking mes-
sage “Set MEM” is shown on the LCD.
At the end of this operation all the pa-
rameters are reset to their default
values. Calibration data is also reset.
For this reason the "CAL" flag blinks
until the pH calibration is performed.
The error detection for dead loops is performed by watchdog
(see below).
You can use special setup codes, perform selftest procedures
for LCD, keyboard, EEPROM, relays and LEDs, watchdog.
The operation of these functions is outlined in the setup sec-
tion. The selftest procedures are described in detail in the
following subsections.
DISPLAY SELFTEST
The display selftest procedure consists of lighting up all of the
display segments together. The Display test is announced by a
scrolling "Display test" message.
The segments are lit for a few seconds and
then switched off before exiting the selftest
procedure.
KEYBOARD SELFTEST
The keyboard selftest procedure begins with the message “But-
ton test, press LCD, CAL and SETUP together to escape”. The
LCD will then show only a colon.
As soon as one or more keys are pressed, the appropriate
segments out of
88:88
corresponding to the pressed keys,
will light up on the screen.
For example, if SETUP and
are pressed together the LCD will
look like this:
