Safety Integrated - Industry - Siemens

Protective door with door interlocking via a magnet-field
lock according to Category 4 of EN 954-1
Automation Function
Scope of Validity of this Functional Example
Locking mechanisms equipped with a tumbler are mechanical
or electrical mechanisms which only allow a machine to be operated
when the door is closed and locked. The interlocking
remains in place until there is no longer any risk of injury due
to dangerous machine functions or movements. Monitoring is
usually carried out by a speed monitor or a standstill monitor.
In this example, machine movement/standstill is simulated by
the door release button.
A standard AS-i network consists of control/master, power
supply unit, a yellow AS-i cable and various slaves. Only two
further components are necessary for safe usage: A safety
monitor and safe slaves.
Each safe slave is programmed with a factory-default code
table that clearly identifies each slave for the safety monitor.
At each master prompt, correlation is checked between the
code value expected by the comparator (safety monitor) and
the code value actually sent by the slave. In the case of deviations
or time-outs, disconnection via 2-channel OSSDs occurs
on the safety monitor.
The protective door is monitored via a SIRIUS position switch
equipped with a magnet-field lock by an ASIsafe K45F module
according to Category 4 of EN 954-1. When the door release
is activated, the safety monitor switches the downstream contactors
with positively-driven contacts via the first OSSD according
to Stop category 0 of EN 60204-1. The protective door
interlock is enabled with a delay.
A drive is shut down in this example. When the protective door
is closed, a manual start is carried out after the position switch
and the downstream contacts have been checked.
Functionality of the Functional Example
Problem
Implementation of a protective door interlock with a magnetfield
lock via ASIsafe. Category 4 of EN 954-1 is to be attained.
Solution
In the example presented here, an actuator mounted in the
door moves into a form-fit mounted position switch with a
tumbler. During the potential danger (machine in operation),
the actuator is kept in position (and thus the door also remains
closed) by the power supply being supplied to a magnet in the
position switch. This type of interlocking is referred to as a
magnet-field lock.
Advantages / Customer Benefits
■ Secure and non-secure data on one bus
■ Simple assembly thanks to standardized AS-i technology
■ Existing system can be quickly and easily expanded
■ Integration of safety signals in the system diagnosis
■ Failsafe PLC or special master not required
■ Space-saving design thanks to compact safety combination
■ Simple configuration via the asimon software
■ The protective door is no longer locked in the case of a
power outage.
Functional Example No. CD-FE-I-035-V10-EN 117
Ex. No.
4.6