From embeddedTS Manuals

The TS-8160 features a AVR that has the ability to cut power to the macrocontroller for a specified amount of time. You can also use the jumper labelled 'WAKE', or the press the button on SW1 to restore power to the macrocontroller.

The ts8160ctl is available here.

Sleeping the board is essentially a shutdown. It is recommended that you have all of your filesystems in a read only state before running this command to avoid disk corruption. This example will simply shut down the macrocontroller for 20 seconds.

ts8160ctl --sleep 20

Power consumption during sleep mode is approximately 100uA.

Note: Sleep times will be rounded up to the granularity of sleep, which is 8 seconds for sleeps under ~3 days and 2048 seconds for longer sleeps. Actual sleep time will be +/- 10% the requested time due to low-power oscillator variation.