Description
The ECU is a mandatory PCB module for M Class PA/GA systems. The ECU manages the internal process of data collection and presents data to the dedicated LAN on demand. The ECU is a compact DIN rail mounted module, powered from the local PA/GA rack.
Battery backup
The ECU includes onboard battery backup. The health of the battery is monitored by the ECU management system and the M Class server is notified when batteries need to be changed (typically 5 year period).
The purpose of battery backup is to ensure the ECU is able to detect and log critical power events such as loss of system power and return of system power. The battery keeps the ECU core functions operating in the absence of normal power until logging activity is complete, then the ECU enters a low power sleep mode. The battery also maintains the real time clock on the ECU during power-out so that subsequent logging at power up is accurately time-stamped.
Data logging
The ECU reports status to the server on a regular basis. However, the server is not considered as critical path and may go off-line at any time. The ECU includes the option to log system events to an optional on-board SD card (2 GB of storage would allow in excess of 300,000 events to be recorded with a timestamp). Larger SD cards would extend event log capacity further. ECU logging only records changes in status (deltas) and does not record status or report status for every sample taken. This massively improves storage capacity and reduces network traffic.
Data collection and forwarding
The ECU is implemented as the master device on the internal M-LINK bus which interconnects between various modules of the PA/GA rack. The ECU is able to monitor the M-LINK bus continuously. The ECU is the central monitoring coordinator in the PA/GA rack. By default it is able to monitor up to 30 M Class devices connected with an M-LINK bus.
