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DOK-SUPPL*-VEH*30.2***-PR03-EN-P
Rexroth IndraControl VEH 30.2 Hand-Held Terminal
Application of hand-held terminals
in special operation modes
●
the system has been built in 2-circuit technology and a build up of multi‐
ple faults will not lead to loss of safety (category 4)
Starting from category 3 it is also important in this context that individual
faults are detected in time to avoid a build up of faults, which may finally lead
to loss of safety.
Faults that have to be detected in electric and electronic systems are e.g.
cross-circuits between multiple circuits, interrupts, short-circuits or contacts
that stick together. Special certified safety control devices are often used to
detect faults in the individual safety circuits, which already have a certain PL.
The overall PL quoted for these devices is only attained, however, if also the
whole machine circuit under review lies within the scope of the respective PL.
The PL must always be considered in relation to a complete safety function
and not as applied to individual components or parts.
A guide for easy calculation of the PL for a safety function consisting of sev‐
eral individual components can be found in standard EN ISO 13849-1 (chap‐
ter 6.3 and appendix H and I).
If safety components connected in series, the individual component with the
lowest PL determines the PL of the whole safety function. For example a
safety function consisting of three components, one with category 4 PL e, an‐
other one with category 3 PL d and a third component with category 2 PL c
will have a PL c for the whole safety function. This means that a fault will lead
to loss of safety, although components with category 4 PL e are integrated
into the safety function, as one of the components being used has category
2.
If several Performance Levels (PL) are chained, the overall PL can decrease,
see also standard EN 13849-1 (chapter 6.3).
The proof of attainment of a safety category can take place with the aid of a
FMEA (Failure Mode and Effects Analysis). In this analysis all the faults that
could possibly arise are simulated, either theoretically or in practice, and it is
demonstrated that the requirements of the category are fulfilled.
For manual controlling of machines in special operation modes, where safety
depends on the timely reaction of the operating staff, it is absolutely essential
that the operator can overlook the operating area.
The Hand-Held Terminal has the advantage that the operator can get very
close to the operating area.
At the same time, the danger of misuse increases with mobility since, in re‐
mote locations where it is not possible to observe the operating area, ma‐
chine movements can also be set in motion with the Hand-Held Terminal,
knowingly or unknowingly.
The user of the machine, therefore, has to find the right compromise between
necessary flexibility and a reasonable limitation of the working range when
selecting the corresponding cable length for the Hand-Held Terminal.
The working range of radio-operated hand-held terminals cannot be limited
by means of the cable. Therefore additional technical solutions are required
for these hand-held terminals.
If the machine or equipment is operated with the Hand-Held Terminal, care
must be taken at this time to ensure that operation can only be controlled by
the Hand-Held Terminal and cannot be operated from any other point on the
equipment. The hazard zone may only be entered by the person who is ope‐
rating the Hand-Held Terminal. If it should be necessary for more than one
person to work in the hazard zone at the same time, each person present re‐
quires an enabling device and machinery movement may only be allowed af‐
ter all the enabling buttons have been activated.
Bosch Rexroth AG
37/109
Technical Data
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