6 horstCONTROL I/O
41
Safe Shut-down of the General Digital Outputs
Digital outputs DO01 to DO16 are supplied by the +24 V
power supply via a bridge at X17.7/X17.8. One bridge
each is inserted here in the delivery state. If this bridge
and the associated ground connection are routed to the
connected actuators via a safety relay pair, these can be
switched off in a safety-critical manner (see wiring exam-
ple
Safe Deactivation of the Digital
these normal digital outputs can be used for safety-critical functions, if the connected actuators are in a
safe state when deenergized.
6.4.6
+24 V Power Supply
For the power supply to external devices, 22 +24 V connections and 24 ground connections are available.
All +24 V connections and the general digital outputs DO01-DO16 together can be loaded up to a maxi-
mum of 7 A. If the total current is briefly exceeded, the drain is limited to this 7 A, and if it is exceeded for
a longer period of time (e.g. due to short circuit) the +24 V power supply is switched off. The safety-critical
outputs as well as the digital outputs DO17-DO18 are not affected by this. In the event of a deactivation,
the power supply attempts to switch back on again after about 500 ms. If unsuccessful, a new attempt
will be started every 500 ms.
Likewise, an ex24 V power supply can be placed at
terminal X17.8 (see adjacent figure). It is therefore possible
to operate the general digital outputs DO01-16 with an exter-
nal power supply if the ground connection of the external
power source is connected to the ground of the horstCON-
TROL. The permissible values for an external power supply
are specified in the table below:
Table 6-8: Characteristic values of the +24 V power supply
Power supply
min.
typ.
max.
Unit
Internal: Voltage
23.5
24
24.5
V
Internal: Current
0
-
7
A
External: Voltage
15
24
30
V
External: Current
0
-
10
A
Fig. 6-14: +24 V power supply
Fig. 6-13: Bridge for power supply
DO01-16
Fig. 6-15: Feed of an external
power supply
Summary of Contents for HORST900
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