Figure 20: Electrical diagram of the reset device
Using an integrated restart interlock
T
he restart interlock is configured once the reset pushbutton has been connected.
When the restart interlock is configured, the application diagnostic output located on
the same plug connector as the reset pushbutton signals when the reset pushbutton
needs to be pressed.
The following applies to the restart interlock:
•
If the protective field is clear once the machine has been switched on or following
an interruption, the OSSDs do not switch to the ON state
•
If someone presses the reset pushbutton and then lets go of it when the protec‐
tive field is clear, the OSSDs switch to the ON state
•
The machine may not restart yet. The operator must also press the machine start
button after having pressed the reset pushbutton.
Single system
Onl
y one reset pushbutton may be connected to a single safety light curtain.
Further topics
•
"Configuring the restart interlock", page 63
4.4.2 External device monitoring (EDM)
Overview
T
he safety light curtain has internal external device monitoring.
The external switching elements (external device monitoring, EDM) must be inspected
in line with the regulations which apply at the place of installation or the required relia‐
bility of the safety function.
The external device monitoring (EDM) monitors the status of downstream contactors.
Prerequisites
•
P
ositively guided contactors are used for shutting down the machine.
If the auxiliary contacts of the positively guided contactors are connected to the
external device monitoring, the external device monitoring checks whether the
contactors drop off when the OSSDs are switched off.
Principle of operation
If you configure external device monitoring, the safety light curtain then checks the con‐
tactors after every interruption to the light path and before the machine restarts. Exter‐
nal device monitoring is then able to detect if one of the contactor's contacts is welded,
for instance. In this case, the OSSDs remain in the OFF state.
PROJECT PLANNING 4
8022883/2019-03-07 | SICK O P E R A T I N G I N S T R U C T I O N S | deTec4 Ex
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Subject to change without notice
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