EUCHNER CET - Manual (Page 6)

CET Help for Setup and Service
Page 6 of 10 Subject to technical modifications 01/2013
3.2 LED STATE flashes twice (series operation)
Fault symptom:
The CET-AR displays the fault state “Input fault (e.g. missing test pulses, illogical switching state of downstream
switch)”.
Possible fault causes:
 24 V DC missing at inputs I
A
and/or I
B
(only first device in series)
 In a series circuit, I
A
is connected with O
B
or I
B
is connected with O
A
 In a series circuit, conventional safety components (switching contacts) are connected to I
A
and/or I
B
 A safety evaluation unit or a safe control system with pulsing outputs is connected the inputs I
A
and/or I
B
.
 All connections are correct, but there is no common potential for the series-connected devices (several power
supply units for one chain)
 One of the units' power supply was briefly interrupted.
Remedy:
1. Check the wiring and correct it if necessary or switch the clock pulses off
2. Press the reset button that controls ALL installed reset inputs for the series circuit.
3. Release the reset button again.
4. Wait until LEDs STATE flash three times or stop flashing entirely (after approx. 8 s)
5. Close the safety doors
 The CET-AR are now ready for operation again
3.3 LED STATE flashes three times
The device indicates that it is ready to teach in a new actuator. Observe the corresponding specifications for teaching
in an actuator in the system manual.
Flashes three times
Flashes twice