  We present the current development of the Monitoring, Logging and Alarm
subsystems in the framework of the Array Control and Data Acquisition System
(ACADA) for the Cherenkov Telescope Array (CTA). The Monitoring System (MON) is
the subsystem responsible for monitoring and logging the overall array (at each
of the CTA sites) through the acquisition of monitoring and logging information
from the array elements. The MON allows us to perform a systematic approach to
fault detection and diagnosis supporting corrective and predictive maintenance
to minimize the downtime of the system. We present a unified tool for
monitoring data items from the telescopes and other devices deployed at the CTA
array sites. Data are immediately available for the operator interface and
quick-look quality checks and stored for later detailed inspection. The Array
Alarm System (AAS) is the subsystem that provides the service that gathers,
filters, exposes, and persists alarms raised by both the ACADA processes and
the array elements supervised by the ACADA system. It collects alarms from the
telescopes, the array calibration, the environmental monitoring instruments and
the ACADA systems. The AAS sub-system also creates new alarms based on the
analysis and correlation of the system software logs and the status of the
system hardware providing the filter mechanisms for all the alarms. Data from
the alarm system are then sent to the operator via the human-machine interface.
