Watchdog (AMC-IP)

Software process watchdog

(watchdog service checking that all main processes are running)

A System Monitoring Daemon (amc_ip_cmd_srv) continuously monitors that the AlphaCom software (amcd) are running by receiving an alive signal from amcd. The same amc_ip_cmd_srv daemon do also send alive signals to the Hardware Whatchdog circuit. If the alive signal from amcd is missing the amc_ip_cmd_srv will first try to do a soft reset of the AlphaCom software and sime system processes. If the AlphaCom system fails to start again the amc_ip_cmd_srv will stop toggling the hardware wdog, and a full system reset will occur.

Software application watchdog

(check if link to AlphaCom is up etc)

Recovery from a failure situation

(Recovery from a failure situation if the watchdog detects a failure e.g.:)

• Restart the process
• Restart with OS
• Power down/up.

System architecture

The watchdog on the AMC-IP board is comprised of two main elements; the watchdog circuit and the system monitoring software running on the CPU. The watchdog circuit requires an alive signal to be toggeled by the CPU regularly. This signal is toggeled by the system monitor at 100 Hz as long as all required processes is up and running. If the system monitor detects irregularities or hanging processes, it will attempt to restart these processes. If this dosen't work, it will stop toggeling the alive signal, and the entire AMC-IP board is reset.