Fayat Dynapac DR7X Operating Instruction page 21

Concerning your safety – Definition of responsible persons
n have made himself familiar with the operation of the machine,
n be physically and psychologically able to drive and operate the
machine.
Persons under the influence of alcohol, medication or drugs are not
allowed to operate, service or repair the machine.
Maintenance and repair work requires specific knowledge and
must therefore only be performed by trained specialists.
DR7X 21