Bosch rexroth CytroForce-M, Operating Manual

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27 / 85
Servo-hydraulic actuator
Product description
Bosch Rexroth AG RE62270-B, 01.21
Fig. 5: Structure overview of PFC
5.1.8 Functional safety
For safety-related applications for personal protection at machines, e.g. in case
of gravity-loaded axes in press applications, the servo-hydraulic actuator is
available in a safety-capable variant. It is extended by additional components in
the hydraulic and electrical system, that is, the scope of delivery is extended by
safety components.
Extension
The control block of the servo-hydraulic actuator is (optionally) provided with
two valves connected in series, each with separate spool position monitoring
function, in a line to a safely isolated chamber.
In the optional slot for safety technology, the control section is fitted with an
optional S4 card for the drive-integrated safety technology “Safe Motion”.
The scope of delivery is extended by a control unit for inductive loads, HAT02.1.
The servo-hydraulic actuator is a safety-related sub-system within a safe
machine. The responsibility for furnishing proof of and certifying the safety
functions of the complete machine lies with the machine manufacturer. The
characteristic safety values of various safety functions that are required for a
general assessment can be found in the technical data sheet of the servo-
hydraulic actuator.
Safety functions
The integrated safety technology generally distinguishes between encoder-
dependent and encoder-independent safety functions. For personal protection
at machines, encoder-dependent safety functions are applicable according to
ISO 13849-1 Category 3, PL d and IEC 62061 SIL 2, and safety functions inde-
pendent of an encoder are applicable according to ISO 138491 Category 4, PL
e and IEC 62061 SIL 3.