Safety engineering
Device modules
Safe output
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EDS94AYAE EN 6.0
1.2.5 Safe output
1.2.5.1 General
Via the safe output O1A/O1B information can be output to a higher−level unit (e.g. safety
PLC) or external switching elements (actuators) can be controlled.
The feedback output is potential−free and must be supplied separately with 24 V.
ƒ The status of the safe output is controlled via two ways:
– directly from the safety module (parameter setting required)
– via the PROFIsafe output data
ƒ The safe output is PP switching, i.e. two plus channels are switched.
ƒ The safe output in ON state is cyclically tested by quick LOW switching.
– The A and B channels are tested at different times in cycles of approx. 2 s, with
test pulses of < 1 ms.
– When selecting the downstream control elements, ensure that the test pulses will
not be detected as LOW signal.
These errors will be detected and set the output to OFF state:
ƒ Short circuit to supply voltage.
ƒ In the ON state: Short circuit between the output signals.
ƒ IN the OFF state: Missing 24−V supply voltage at the terminal 24O is detected as
"Stuck−at−Low" error.
These errors are not detected:
ƒ In the OFF state: short circuit between the output signals.
The output can be assigned multiple feedback information by parameter setting:
ƒ Status of the safety function
ƒ Information on error responses
The code C15060 contains information on the status of the feedback output.
Additional conditions for SM301 in VB 1.1 version:
ƒ With active cascading in C15035 the SD−Out1 output cannot be used freely
anymore.