I use Linux.

The watchdog-cmd.sh (that comes in the compressed file along with the binaries) is the shell script that has to be run when a card stops responding. You need to edit it and enable the method that works best for you. My watchdog-cmd.sh looks like this:

#!/bin/bash

## Hard reset: (Requires 'Magic SysRq key (CONFIG_MAGIC_SYSRQ)' enabled in kernel.)

echo "--------------" >> /opt/optiminer/optiminer-zcash.log
echo 1 > /proc/sys/kernel/sysrq
echo u > /proc/sysrq-trigger
sleep 1
echo b > /proc/sysrq-trigger

The mine.sh has the watchdog-cmd.sh already configured.

In my case, the watchdog-cmd.sh never gets fired, so I wrote another script to monitor the log file and wait for something like has not produced any solution in it, when the text is found, the script will call the watchdog-cmd.sh. This solution has been working for me quite fine.