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DOK-SUPPL*-VEH*30.2***-PR03-EN-P
Rexroth IndraControl VEH 30.2 Hand-Held Terminal
Application of emergency stop but‐
ton and stop button on the
IndraControl VEH 30.2
Notes on the enabling button
●
The Machinery Directive does not specify any detailed requirements re‐
specting the coloring of the operating elements for emergency stop. The
requirement is as follows: "The device must have clearly identifiable,
clearly visible and quickly accessible controls".
"Emergency" buttons are usually identified in red-yellow color. The spe‐
cific design should have a signaling function whose effect is that any
person, and especially untrained people, can quickly recognize the ope‐
rating element as the device to eliminate a hazard in the case of an
emergency.
One imperative requirement for equipment identified in this way is,
therefore, that it must be possible to trigger a safe state at any time and
in any operation mode, without further knowledge of the machine (see
also EN ISO 13850). It is not acceptable for an emergency stop button
to be enabled temporarily, since this can lead to faulty operation and life
threatening loss of time in panic situations.
If hand-held terminals are considered in relation to these requirements it
is evident that a differentiation must be made as to whether an emer‐
gency stop button on the hand-held terminal may be used or not, de‐
pending on specific criteria and applications.
Depending on the specific use case, the risk assessment of the machine
(according to EN ISO 14121-1) can lead to different results, e.g. for
stopping a system. The present document cannot make the decision. In
the specific case, the machine manufacturer has to evaluate the case
under consideration of all applying standards.
Temporarily pluggable hand-held terminals bear the risk of being availa‐
ble with ineffective safety device after having been disconnected from
the device. In this case a gray stop button would not be detected as
operating element for emergency stop. A disconnected hand-held termi‐
nal with red-yellow button could be taken for such an operating element;
and the confusion could lead to a dangerous situation. In this case the
professional organization demands "organizational measures" for elimi‐
nating the danger, e.g. shutting away the device.
●
Many machines feature a normal operation mode as well as a special
operation mode. The machine fulfils its primary mission in normal (auto‐
matic) operation. In this operation mode, safety is guaranteed by closed,
separating protective devices and/or with functioning, not separating
protective devices.
The special operation modes of a machine serve to maintain normal op‐
eration. In doing so, safety must be guaranteed in a way that is different
to normal operation, because hazardous areas of the machine can now
be entered and targeted machine movements have to be possible. The
enabling button plays an important role.
This application requires the enabling button to eliminate the hazards
that are to be controlled in a timely manner, before any personal injury
occurs. For this purpose additional safety measures may be necessary,
such as safely reduced speed of drive mechanisms.
In contrast to the emergency stop button (and the stop button), a ma‐
chine in special operation modes with an enabling button is in a safe
state as long as this enabling button is not activated (see the following
figure):
Bosch Rexroth AG
39/109
Technical Data
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