Siemens 6SN1123-1AA00-0DA2 Configuration Manual page 291

8 Important Circuit Information
8.7 Circuit examples =1 to =9 with SIMODRIVE 611
Application
Functions
8-290
If hazardous operating states exist, if the PLC function keys fail, or for any other
unpredictable situation, the drives can be stopped in a safety–related way by
releasing the agreement button.
Notice
For dynamic drives with inadmissible speed increases, potential hazards can
occur under fault conditions due to the response times of personnel and the
delay when the agreement device switches. These hazards must be reduced
by applying additional measures, e.g. a safety–related speed monitoring
function. Various type C Standards, e.g. for machine tools, specify a safely
monitored speed in the setting–up mode for spindle drives.
Circuit example =6 "Drives, automatic operation with
protective door monitoring"
In the automatic mode, the working zone of a machine is isolated using a mov-
ing, closed protective door (e.g. guard). In the circuit example, the protective
door is interlocked and cannot be opened while the drives are running or if other
hazardous operating states exist. This is realized using a position switch with
tumbler mechanism with an interlock using spring force with sealed auxiliary
release. Automatic operation for the drives is only enabled if the protective door
is closed and interlocked via the position switch.
Depending on the hazard analysis, the user must decide whether, e.g. a second
limit switch is additionally required for the door monitoring function.
The protective door is prevented from being opened as long as a hazardous
state exists, e.g. as a result of the drives running–down. The enable signal is
only issued with a time delay after the drive with the longest braking time has
been reliably and safely stopped or optionally using the standstill signal of an
external speed monitoring function.
For several applications, e.g. if personnel can enter the working area of a ma-
chine, the tumbler mechanism of the protective door is implemented using a
position switch interlocked with magnetic force. This is for safety–related rea-
sons. When the line supply or control voltage fails, the position switch can be
used to release the protective door and allow it to be opened.
Request protective door enable
The drives must initially be shutdown using pushbutton =4–S31 – stop drives –
or optionally, e.g. at the end of the NC program by the output of an NC auxiliary
function, PLC O18 closes contactor –K18.
The protective door enable is requested using pushbutton –S15. Contactor –
K15 is activated, interlocked through the PLC logic when the drives are stopped
and shut down. This means that contactors =4–K33 and =4–K36 have dropped
out. PLC logic: PLC O15 = "1", if =4–I33 and =4–I36 = "0" signal.
When requesting that the protective door is enabled, in the secured working
zone of the machine/plant, all hazardous motion and other potential hazards of
the user–side machine control must be shutdown. The shutdown must then
realized in a safety–relevant way using the released or opened protective door.
SIMODRIVE 611 Configuration Manual (PJU) – 02/2012 Edition
© Siemens AG 2012 All Rights Reserved
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