R&S®GB127MU Antenna Control Unit
The Mast Control Unit R&S® GB127MU is the interface between a telescopic mast and the Antenna Control Unit R&S® GB127M. It consists of a metal case, a control board with relays, optocouplers, power supply and connectors.
With a switch connected to the MAN/AUTO jack, the user can select automatic mast control via the R&S® GB127M. Manual control is selected by means of a manual control switch connected to the MAN MAST CONTROL jack.
The high power relays that switch the motor current are part of the telescopic mast. These relays are controlled by the UP/DOWN switches in the R&S® GB127MU. The exact mast position is measured by an encoder which is also part of the telescopic mast. The mast control unit forwards this position information to the R&S® GB127M via an RS-232-C serial interface.
A special end position detection facility on the control board forwards control signals to the R&S® GB127M when the mast reaches its upper or lower end position. The signal at the lower end position is used to initialize the position measurement.
Additional end switches in the telescopic mast provide mast alarm signals that could be used e.g. to switch a warning lamp or to block the ignition of the vehicle in order to prevent it from moving while the mast is not in the transport position.
