Datasensing SH4 BASE-STANDARD, Product Reference Manual, Page: 48 / 103

FUNCTIONS
40
SH4 BASE-STANDARD
EDM
(Standard models only)
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).
Figure 8: EDM wiring
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.
Figure 9: EDM function timing
T
c
 350 ms (time between OSSD OFF-ON transition and EDM test)
T
0

100 ms (time between OSSD ON-OFF transition and EDM test)
(two different times for the mechanical contact driven by a spring)
Configuration
The configuration of EDM is done by connecting the EDM SEL signal ( pin 3 , green ) as
described below:
• EDM SELECTION connected to 0V (floating): EDM ENABLED
• EMD SELECTION connected to 24V: EDM DISABLED
24Vdc
OSSD_1
OSSD_2
EDM
OSSD_1
OSSD_2
EDM
ESPE ESPE Safety MPCE
forced guide
relais
EDM ENABLED EDM DISABLED
floating
nc
nc
no
no
ON
OFF
24Vdc
0Vdc
OSSDs
STATUS
EDM
Tc
To