Operating Instructions
– LBA63 TOLL HIGHWAYS – 2019 Version
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5
Operating principle
The barrier comprises two sections: a mechanical section (housing, boom, compensation device) and
an electrical section (control panel, reduction gear, sensors, magnetic loops, etc.).
The electrical section commands the mechanical section.
The control panel comprises a programmable logic controller (PLC) (or electronic card) which runs a
frequency converter which in turn runs the barrier motor.
This PLC is also connected to various electrical accessories for the barrier: inductive position sensors,
magnetic loop, infrared cell, flashing light, etc.
The inductive sensors indicate the position of the boom to the PLC so that it can run the frequency
converter.
A safety device (magnetic loop, infrared cell, etc.) under the barrier is recommended to detect any
vehicle or pedestrian under the boom so that the command logic prevents it from closing if appropriate.
Automatic closing functions after passage or after time delay can be activated via the control panel
terminal boards.
The control panel also sends information on the state of the barrier as dry contacts (NO or NC).
The acceleration/deceleration speeds and ramps can be adjusted via the frequency converter.
The compensation device is a spring that compensates for the weight of the boom when the barrier is
activated.
The barrier is called “reversible” as the boom can move under power with no need to use a crank. Some
reversible barriers can thus reopen automatically in a power cut thanks to the compensation spring.
Where the boom is unhinged by less than 60° compared with its normal position, the boom returns
automatically in place thanks to a cylinder system.
Where the barrier is unhinged by more than 60°, it has an automatic boom hinging function thanks
mainly to the hinging cam.
