Edm - Datasensing SH4 ADVANCED Product Reference Manual

EDM

The External Device Monitoring (EDM) function controls external devices by verifying
the OSSDs status. To correctly use this function user must connect EDM input to a N.C.
to 24V contact of the device to control (forced guide relay).
The function controls the N.C. contact switching according to the changes of the OSSD
status.
The timing diagram below explains the relationship between the cause (OSSDs) and the
effect (EDM), with the maximum permissible delay.
OSSDs
STATUS
EDM
T  350 ms (time between OSSD OFF-ON transition and EDM test)
c
T 100 ms (time between OSSD ON-OFF transition and EDM test)
0
(two different times for the mechanical contact driven by a spring)
24Vdc
OSSD_1
nc no
OSSD_2
nc no
EDM
forced guide
ESPE
relais
EDM ENABLED
Figure 34: EDM wiring
Tc
Figure 35: EDM function timing
OSSD_1
OSSD_2
EDM
floating
ESPE Safety MPCE
EDM DISABLED
To
PRODUCT REFERENCE GUIDE
EDM
ON
OFF
24Vdc
0Vdc
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