Festo Контроллер двигателя CMMD-AS User Manual

Page 78

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4. Functional safety engineering

78

Festo P.BE-CMMD-AS-HW-EN 1002NH

Among other issues, the EN 60204-1 standard deals with the handling of emergencies and
defines the terms EMERGENCY OFF and EMERGENCY STOP (see table).

Handling

Definition (EN 60204-1)

Danger case

EMERGENCY
OFF

Electrical safety in case of emergency by
switching off the electrical energy to all or
part of the installation.

EMERGENCY OFF is to be used where a risk
of electric shock or other electrical risk
exists.

EMERGENCY-
STOP

Functional safety in an emergency by
bringing a machine or movable parts to
a standstill.

EMERGENCY STOP is used to stop a process
or a motion if this creates a danger.

Table 4.1 EMERGENCY OFF and EMERGENCY STOP as per EN 60204-1

The standard EN 61800-5-2 describes various safety functions that can be used
dependent on the application.
For the position controllers of the CMMD-AS family, the STO and SS1 safety functions
have been implemented through external circuitry.
Galvanic isolation does not occur with the STO function. As a result, this does not have
any protective function against electric shock. In the sense of the standards, an
EMERGENCY-OFF system cannot be implemented with the STO, because this requires the
complete system to be switched off via a mains power isolator of some kind (main power
switch or mains circuit breaker).

Safety function as per
EN 61800-5-2

PILZ component

Switch-off behaviour Stop category in

accordance with
EN 60204-1

STO

Safe Torque Off

PNOZ X2P
Relay outputs forced:

- 2 safety contacts no delay

Connection options for:

- EMERGENCY STOP buttons
- Protective door limit switches
- Start button

0

SS1

Safe Stop 1

PNOZ XV2P
Relay outputs forced:

- 2 safety contacts no delay
- 2 safety contacts relapse

delayed

Connection options identical
to X2P
Fixed or adjustable relapse delay
Cancelling the time delay through
Reset button

1

Table 4.2 Overview of the safety function in accordance with EN 61800-5-2

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