Garnet SeeLevel II 900-D4D DUAL, Manual, Page: 7 / 24

Page 7 900D4D Manual
• To select °F or °C for the temperature display.
• To program the 4-20 mA outputs.
• To set the alarm points.
• To program the gauge calibration.
• To enter the security codes which control access to the various
gauge functions.
Display Batteries: A set of four alkaline ‘AA’ cells in the display
enclosure powers all gauge display functions except for the 4-20
mA outputs. This allows for total stand alone operation of the
gauge. This battery pack should last from 3 to 4 years, depending
on usage of the LCD backlight. The batteries can be field replaced
with simple hand tools, and all programming is retained when the
batteries are removed.
Display Alarms: The display has 4 alarm points each with a high
and low set point all of which can each be programmed via the
keypad to turn on or off at any level in the tank. Alarms 1 and 2
operate from the left volume (fluid volume 1) and alarms 3 and 4
operate from the right volume (fluid volume 2). The alarm outputs
are transistors which conduct to ground, and are rated at 100mA
at 24 volts. These outputs are for connecting to an external alarm
system which has been designed to work with this type of output.
The alarm outputs and ground are available at a terminal block
inside the display enclosure.
WARNING: The use of alarm points is entirely at the owner’s
risk due to the nature of connecting external horns or lights,
the reliability of external horns or lights, and the requirement
for external switches to disarm them.
NOTE: The 900D4D is available from the factory with either a
4-20 mA output or a 1-5V output for volume and temperature.
Display 4-20 mA Outputs: The display has four 4-20 mA
outputs available at terminal blocks inside the display enclosure.
Two of the 4-20 mA outputs are the volumes; they derive their
output values from the volume displays. 4.00 mA corresponds
to an empty tank (for example, 0 barrels) and the user sets the
full scale (20mA) value of the output. The display only has to be
programmed once for all three outputs, so they must all have the
same scale calibration. For example, if the user set the full scale
at 400.0 barrels and the barrel reading was 300.0, then the 4-20
output would be 16.0 mA (300/400*16mA+4mA). These outputs
can also be programmed to be off.