Ground Watchdog Timer

The system is equipped with a ground watchdog timer (GWDT) that must be reset periodically using a telecommand. If the GWDT expires, it clears the boot tables for the rx and tx groups and reboots the system to return to the fallback settings (or default if no fallback configuration is stored). The GWDT is enabled by default with a timeout of 24 hours. The timeout value can be set between 1 hour (3600 seconds) and 1 week (604800 seconds) using the sys.gwdt.init property or set to zero to disable the timer.

The current GWDT counter value can be read back through the sys.gwdt.counter property. This value is initialized to sys.gwdt.init when the system boots, and decrements every second. It can only be reset by setting the sys.gwdt.reset property to the special value SL_SRS3_GWDT_RESET_KEY (0xBB5990C1).

The client library provides wrapper functions to reset and read the current GWDT value: Ground Watchdog

Reboot Timer

The conf.reboot property is used to engage a timer that reboots the system in a specified number of seconds. This can e.g. be used before experimenting with radio settings, to ensure the system returns to a working configuration without having to wait for a GWDT reboot. The reboot timer can not be enabled by default and will not reset any properties like the GWDT.

To enable it, set the conf.reboot property to the number of seconds until reboot. The property value can be read back and will decrement every second. To disable the timer, set the property to 0.