Circuit diagram example
4.2 Operating principle
Safety engineering with AS‑Interface in the SIMATIC ET 200SP, including typical circuit diagram
Function Manual, 08/2020, A5E44991382002A/RS-AB/002
23
The fail-safe controller monitors the emergency stop command device and the safety switch
on two channels. Both devices have an integrated AS-i slave and are thereby connected to
the AS-Interface. The two signals are transmitted to the fail-safe controller using the
combination of CM AS-i Master and F-CM AS-i Safety (ET 200SP station modules).
The protective door position is monitored by a safety switch. In addition, the door is locked by
means of a tumbler integrated in the safety switch. When the command to release the door is
issued by means of a toggle switch, safety switch-off of the power contactors takes place via
the fail-safe controller. On expiry of a set time, the tumbler is unlocked and access to the
machine is enabled.
After the door has been closed and locked again, and the feedback circuit of the power
contactors is closed, the Start button can be used to switch on again. When the emergency
stop command device is actuated, the fail-safe controller also switches off the power
contactors in a safety-related way. If the emergency stop command device is reset and the
feedback circuit is closed, the Start button can be used to switch on again. Start pushbuttons
and toggle switches are also read in via the AS-Interface.
The "Stopping in an emergency" safety function is designed up to SIL 3 or PL e.
The "Protective door monitoring" safety function is designed up to SIL 2 or PL d.
If the emergency stop command device is actuated, the machine is
shut down safely.
If the protective door is opened, the machine is shut down safely.
-safety-related tumbler via integrated standard output of 3SF1324-1S.21-1BA4: The
protective door tumbler is not a safety function (non
-safety-
related control of the solenoid). It
can be used to safeguard the production process.
If during the risk assessment a safety level for the tumbler was defined in addition
to the
protective door monitoring, it is then possible to use a mechanical safety position switch with
tumbler 3SE53 without an integrated AS
-i slave. This means that control of the tumbler
solenoids can take place via a fail-safe digital output on the F-PLC, for example.
Taking account of fault exclusions, the use of only one safety switch with or without tumbler
is permissible up to SIL
2 or PL d. Further information is contained in the PDF under the
following link "concerning the use of safety s
witches up to SIL 2 or PL d
(http://support.automation.siemens.com/WW/view/de/35443942)".
To Next Page
Loading...
Need help?
General
