The PAT Load Moment Indicator DS 350 consists of a central (micro) processing unit
(CPU), operating display console, length/angle sensor, pressure transducers, and anti-two
block switches. This low temperature system uses heaters for stable system operation in a
subzero climate. The main electronics are automatically warmed before the system boards
and components are energized. Therefore, a warming period will be required in low
The system operates on the principle of reference/real comparison. The real value,
resulting from the pressure measurement is compared with the reference data, stored in
the central processor memory and evaluated in the micro processor. When limits are
reached, an overload warning signal is generated at the operator's console. At the same
time, the aggravating crane movements, such as hoist up, telescope out and boom down,
will be stopped by activating an LMI lockout solenoid.
The fixed data regarding the crane, such as capacity charts, boom weights, centers of
gravity and dimensions are stored in memory chips in the central processor unit. This data
is the reference information used to calculate the operating conditions.
Boom length and boom angle are registered by the length/angle sensor, mounted inside
the cable reel which is mounted on the boom. The boom length is measured by the cable
reel cable which also serves as an electrical conductor for the anti-two block switches.
The crane load is measured by pressure transducers attached to the piston and rod side of
the hoist cylinders.
The interactive user guidance considerably simplifies the input of operating modes as well
as the setting of geometry limit values.