Could be also:

Fasten the (lockout) tags to the machine´s control panel. 

I found that in the Web: 

"Use a plastic tie to fasten the lockout/tagout tags to the machine's control panel and treat them with the exact respect as a complete lockout/tagout set would be. All rules and procedures still have to be followed, especially since injury and death from an accidental power up is still a possibility. Place an employee by the tags to keep someone from starting the machine. It's worth the cost to have one standing there compared to the loss of an arm or a life.
These are just a few suggestions. Other rules and guidelines may apply."

In time: the lockout system automatically switch machines off, the tag out just warn of the life/health hazards (many preffer to reinforce it with people of Security to overlook and not let people switch them on again.