Functional safety engineering, 1 general remarks and intended use, General remarks and intended use – Festo Контроллеры двигателя CMMS-ST User Manual
Page 79
4. Functional safety engineering
Festo.P.BE-CMMS-ST-G2-HW-EN 1008NH
79
4.
Functional safety engineering
4.1
General remarks and intended use
The CMMS-ST-G2 family of position controllers supports the “Safe torque off (STO)” and
“Safe Stop 1 (SS1)” safety function, providing protection against unexpected starting up
as per the requirements of the standard EN 61508, SIL 2 as well as EN ISO 13849 1, PL d.
Bringing the machine to a standstill must be carried out and ensured by the machine
control system. This especially applies to vertical axes without automatic-locking
mechanics or counterbalancing.
The machine manufacturer must carry out a risk assessment as per the EC machinery
directive 2006/42/EC. On the basis of this risk assessment, the machine manufacturer
must design the safety system for the entire machine, including all integrated
components. This also includes the electric drives.
The new EN ISO 13849 standard uses a changed risk graph for risk assessment and a
deviating principle to achieve the requirements when compared to EN 954.
1
Starting point for evaluation of the risk reduction contribution
L
Low contribution to risk reduction
H
High contribution to risk reduction
PL
r
Required performance level
Risk parameter
S
Severity of injury
S1
Slight (generally reversible injury)
S2
Serious (generally irreversible injury, including death)
F
Frequency and/or duration of the exposure to hazard