First make a new script eg
nano /path/rclone-cron.sh
inside copy/paste ( put # in front !/binbash ,,, forums marks it as bold font )
#!/bin/bash
if pidof -o %PPID -x "rclone-cron.sh"; then
exit 1
fi
rclone sync ....
exit
make file executable
chmod a+x /path/rclone-cron.sh
Put the script in crontab
crontab -e
Make it run at every hour and half, copy paste line bellow in your crontab
0,30 * * * * /path/rclone-cron.sh >/dev/null 2>&1