Design And Function; Transmitter/Receiver Interface; Transmission Method - DEMAG DRC-MJ D3 User Manual

6

Design and function

6.1 Transmitter/receiver
interface

6.2 Transmission method

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Demag DRC D3 radio control systems are designed for the wireless control of
hoist units and cranes. They are the man/machine interface for manually controlled
crane installations. The relevant EU directives and standards are complied with for
this application.
A DRC D3 radio control system consists of one or more transmitters as well as at
least one or more receivers.
This user manual/assembly instructions refers to DRC-MJ D3 hand-held
transmitters in combination with matching DRC radio receivers.
• The Demag DRC-DR radio receiver is a PCB that is designed to be installed
in the electric equipment cover of a DR or DMR hoist unit. The interface of this
receiver component to the crane control system is the CAN safety bus and the
power supply via the DR/DMR electric equipment.
The DRC-DR radio receiver is only suitable for operation with a DR/DMR hoist
unit.
• The Demag DRC-MP radio receiver is a complete unit with its own enclosure
and power supply from the control voltage network of the crane installation.
Relay contacts for the individual control commands and the emergency-stop
circuit form the interface of this unit to the crane control system. An additional
semiconductor output with pulse width modulation is provided for variable-
speed crane drives.
DRC-MP radio receivers can be used for a wide range of applications.
Demag DRC radio receivers are equipped for bi-directional radio transmission and
transmit information to the DRC-MJ D3 hand-held transmitter. This increases the
safety and reliability of the radio system. Status information for the crane control
system and the receiver is shown on the screen of the DRC-MJ D3 hand-held
transmitter.
Frequencies in the so-called 2,4 Ghz ISM band are used for transmission of radio
signals between transmitters and receivers.
The proprietary radio transmission method used meets the most demanding
requirements in terms of transmitter density and co-existence with other equipment
that operates in the 2,4 GHz ISM band.
The radio transmission method combines various transmission mechanisms:
A frequency-hopping system ensures that radio transmission is robust and
highly resistant to interference – an adaptive characteristic (LBT) combined with
this enables interference with neighbouring radio applications to be effectively
eliminated.