EUCHNER MGB (V1.2.3) - Manual (Page 6)

MGB Help for Setup and Service
2 Troubleshooting
2.1 LED DIA 1 flashes 2 times (separate operation)
Fault symptom:
The MGB displays the fault state “input error (e.g. missing test pulses)”.
Possible fault causes:
 24 V DC missing at inputs I
A
and/or I
B
 A safety evaluation unit or a safe control system with clocking outputs is connected.
Remedy:
1. Check the wiring and correct it if necessary or switch the clock pulses off
2. Open the safety door
3. Switch the voltage off
or
press the reset button (if present) that controls the integrated reset input.
4. Switch the voltage on again
or
release the reset button
5. Wait until LED DIA1 flashes three times or stops flashing entirely (after approx. 8 s)
6. Close the safety door
 The MGBs are now ready for operation again
2.2 LED DIA 1 flashes 2 times (series operation)
Fault symptom:
The MGB 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
 For series operation, I
A
is connected to O
B
or I
B
to O
A
 In case of series operation, conventional safety components (switching contacts) are connected to I
A
and/or
I
B
 A safety evaluation unit or a safe control system with clocking outputs is connected.
 All connections are correct, but there is no common potential for the series-connected devices (several
power supply units for one chain)
Remedy:
1. Check the wiring and correct it if necessary or switch the clock pulses off
2. Open all safety doors on which the DIA LED is flashing (irrespective of the number of flashing pulses)
3. Switch the voltage off at all devices
or
press the reset button (if present) that controls ALL integrated reset inputs in the series connection
Page 6/12 Subject to technical modifications 115387-01-04/12