
Operating Instructions
Chapter
4
UE 440/470
8 010 432/P097/14-03-05
© SICK AG • Industrial Safety Systems • Germany • All rights reserved
27
Configurable functions
4.2.7
External device monitoring (EDM)
The EDM checks whether the contactors connected to an OSSD of the UE 440/470 are in
the correct state when the protective device responds. If you activate external device
monitoring, the UE 440/470 checks the contactors cyclically after each switch-off of the
assigned OSSD and before the machine is restarted. With this, the EDM can identify if one
of the contacts has fused, for instance. In this case…
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the error message
/
appears in the 7-segment display.
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the assigned OSSD of the safety controller remains switched off.
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the safety controller uses the flashing
LED
+
yellow
to signal "Reset required" with the
internal restart interlock activated.
If the system is unable to change to a safe operational status (e.g. after contactor failure),
the system locks and shuts down completely (see "The Lock-out operating status" on
Page 80). The 7-segment display will then show the error message
.
There is no contactor monitoring (EDM) during Bypass.
Connection of the external device monitoring
You can configure up to two connections for external device monitoring.
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Note the assignment of both connections for external device monitoring for the OSSDs.
The release module required for implementation of external device monitoring (see Page
33) has two inputs for external device monitoring (EDM1 (Out1) and EDM2 (Out2)). The
following assignment applies: EDM1
↔
Out1; EDM2
↔
Out2.
Example:
You switch off a machine via the OSSD connected to output Out1 of the
function module. You then connect its external device monitoring to the connection for
EDM attached to input EDM1 (Out1) of the release module.
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Wire the EDM and the UE 440/470 in the same control cabinet.
The electrical connection of the external device monitoring is described in Chapter 6
"Electrical installation" on Page 54.
Note
Notes