Functional Description - Advent VISLINK Newswift 90 Technical Operation Handbook

VISLINK
4.10

FUNCTIONAL DESCRIPTION

The drive control unit (DCU) controls and monitors all electrical aspects of the Newswift
Motorised System. The DCU internally consists of two PCBs. The top board is the micro-
control board, and the bottom the motor drive board.
T he micro control board (MCB) is the controlling element in the antenna DCU. Based on the
T
Advent standard microcontroller block the MCB has the following interfaces, RS485 serial
communication control port, MDB (motor drive board) interface, motor rotation detectors
(MRD), antenna position sensors, digital inclinometer and safety micro-switch interfaces.
C ommands to the DCU are received on the RS485 serial communication port. These
T
commands, such as deploy, stow, or axis rate commands are then acted upon. The
processor monitors the commands to the stepper motors and the MRD's to calculate the
current angular position of the antenna. The antenna position sensors are used to give fixed
position references for the antenna stow position, calibration references, and outer travel limit
detectors.
T he absolute elevation angle of the RF beam of the antenna is measured using a digital
T
inclinometer, this is controlled and monitored by the MCB.
T he motors, brakes, and the waveguide switch in the antenna system are controlled via the
T
MDB interface. This also enables the MCB to monitor the position of the waveguide switch
and the presence of a motor power supply.
T he antenna position safety micro-switches are connected directly to the antenna control unit
T
(ACU) fitted in the operator control station. The DCU does not monitor these lines, enabling
these signals to be used as safety inter-locks. One micro-switch closure indicates that the
antenna is in a safe stow position. The second indicates that the antenna is in deployed
position where the antenna can be used to transmit.
The motor drive board (MDB) drives the 3 axis stepper motor/brake assemblies, and the
control and monitoring of a 12V-waveguide switch. The main functional elements are the
motor stepper drive module, brake drive and control and the waveguide switch control and
monitors.
The motor power supply is separate from the DCU electronics power supply. This separate
motor supply is monitored by the controlling MCB. The DCU is able to warn the user if the
motor power supply fails.
A manual brake override is provided by using SW1. When this is operated the motor current
is disabled, this operation is detected by the MCB, and a warning given to the user. See
section 4.16 for further details.
Newswift 90-180 Motorised Antenna 18