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2.2.8 Communication
Each of the ACE2 units connected to a CCR or other controllable device has a unique factory
set number and a field-programmable communication address. This address is used by the
ADB Airfield Solutions L-890 ALCMS to direct lighting commands to the corresponding
ACE2. The ACE2 executes the commands and returns the operational status of the element
back to the ALCMS.
Each ACE2 is connected to redundant communication networks via two RS-422 serial
communication ports on the main printed circuit board. The ACE network is comprised of a
communications server and all the daisy-chained ACE2 and ACE units in the lighting vault.
Both the ACE and ACE2 devices can be connected to the same network. The
communications server stays in constant communication with all the ACE and ACE2 units in
both networks while staying in constant contact with the main ALCMS network. This
communications protocol dictates the local ACE2 to store all data and parameters specific to
the controlled element. This characteristic frees up the ALCMS computers from having to
store the parameters for each of the controlled elements. The result of this is real-time
communication among all of the ACE and ACE2 units and the rest of the ADB Airfield
Solutions L-890 ALCMS. If a network connection fails in one of the ACE or ACE2 units,
communication is maintained.
Input/Output Interface
The ACE2 incorporates an input/output interface that supports full FAA L-827/L-829 CCR
control monitoring capabilities. The plugable terminal blocks provide an easy-to-service point
of connection. The ACE2 main printed circuit board contains seven latching relay outputs,
one non-latching relay output, and eight optically-isolated input lines.
The latching output relays are configured to control CCR brightness steps or simple On/Off
control as required by the controlled element. The input lines are configured to monitor any
external event determined by a discrete dry-contact closure. Some examples include
generator monitoring, monitoring of Automatic Transfer Switch position, and control of Circuit
Selector Switch loops. In addition, the ACE2 can be optionally expanded to perform CCR
input voltage and current monitoring as well as airfield circuit cable Insulation Resistance
Monitoring.
Failsafe Functionality
Each ACE2 unit provides a self-contained failsafe feature. This feature insures default
airfield lighting operation in the event of an L-890 ALCMS component failure or a complete
ALCMS failure. In addition, each ACE2 can monitor its output and verify the proper
command is executed. The failsafe system also permits maintenance of portions of the
control system without changing the operational status of the lighting system. The failsafe
system is only used in the ALCMS modes, and must be set up by qualified ADB Airfield
Solutions personal.
The failsafe mode of each ACE2 unit is defined by requirements of the airport/owner. The
failsafe modes are as follows:
1. L
ATCHING
F
AILSAFE
MODE
:
— If the CCR is switched On before the failure, it remains On at the same brightness level
— If the CCR is switched Off before the failure, it remains Off.
2. S
IMPLE
F
AILSAFE
MODE
:
— After a failure occurs, the CCR switches On to a pre-determined brightness level
without regard to the current step.
3. S
MART
F
AILSAFE
MODE
:
— If the CCR was switched On before the failure, it remains On at the same brightness level.
— If the CCR was switched Off before the failure, it switches On to a pre-determined
brightness level.
Graphic User Interface
The ACE2 graphic user interface (GUI) consists of a128 x 64 pixel monochrome, LCD display
and four momentary switch buttons. In typical modes of operation, the upper half of the LCD
displays a monitored parameter. In stand-alone mode, it displays a configuration menu. The
