CAS, a constituent part of the COSAL system, is a scalable measuring system for acquiring, displaying, and forwarding lamp failure figures and current actual values in phase-controlled series circuits of the airport lighting system.
CAS is installed in a 19” drawer, which at the front features a back-lit 4-line LCD display and a membrane keyboard for parameterization and manual operation. At the rear are the plug-in contacts for the power supply, for communication and for connecting the current and voltage measuring transducers of the series circuits. The measuring system can be fitted with any number of measuring modules up to 8, with up to eight circuits connected to each measuring module.
The measured values acquired are made available to the higher-order instrumentation and control system via a field bus. The field buses currently available solely for redundant and non-redundant communication are CAN-BUS and PROFIBUS-DP, while for the non-redundant category the serial protocols RCOM and MODBUS are additionally possible via the system’s own RS485 interface.
The data thus conditioned are shown on the display with a cycle time of approx. 320 ms, together with the name of the circuit concerned, and forwarded to the instrumentation and control system. There is also provision for manual selection of individual circuits for display.