UFC 3-535-01
17 November 2005
step).
13-16.6
Computerized Control Systems
Modern control/monitoring systems for Visual Air Navigation facilities are usually based
on the use of a Programmable Logic Controller (PLC) or a PC computer. These may
have touch screen or track ball user interface, and may use fiber optic cable in place of
the traditional multi-conductor copper control cables to link the various stations.
Commercial standards are available for some components of such systems; however,
standards are not yet established for integrated systems. Often, the computerized
system installed is based on one specific manufacturer's equipment, which locks the
facility into one manufacturer for servicing and parts, often costly to the facility. Also,
new systems often have a response delay from control action by the tower, compared
with the instant response of the traditional relay type systems, resulting in a short
moment of user uncertainty if his selection has been carried through. In selecting and
specifying a computerized control system, technology continues to evolve, the
characteristics presented in Table 13-3 should be considered. Further discussion of this
type system is presented in Chapter 15.
13-16.6.1
General Function for Control and Monitoring
13-16.6.1.1 Minimum operating capabilities: determination of the functional status of
the system; identification of the intensity level at which each circuit is operating.
13-16.6.1.2 Suitable for complexity and particular needs of airfield, and adaptable to
changes (modular).
13-16.6.1.3 Redundancy of equipment or elements crucial for safety.
13-16.6.1.4 High degree of reliability and availability.
13-16.6.1.5 Capable of data exchange with related systems.
13-16.6.1.6 Provide an intuitive operator interface. Include the capability of monitoring
and controlling all visual navigation aids controllable by a conventional control system.
Identify alarm conditions.
13-16.6.2
Basic Peripherals and Features
13-16.6.2.1 User Interface
User interface (controller, maintenance staff, other), user-friendly with secure transfer
and relevant status information for each station. Typical installations use touch screen
or track-ball, based on local preference.
13-16.6.2.2 Display
The display should show continuous visual presentation of the true status of the several
subsystems being controlled/monitored. Graphic display should depict a representation
of the airfield, showing the configuration and location of the various lighting circuits. The
display should indicate the status (i.e., ON/OFF or step), circuit/system identification, as
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