Troubleshooting
474-Add-on Modules
50
Diagnosis
Possible reason
Measure
CPU Unit:
No signal at audio
output (microphone).
No audio connection to the audio source
(microphone) available.
Connect the analog audio source
(microphone).
Check the connection of the audio cable
between the CON Unit and the analog
audio source (microphone).
No signal available.
Switch the analog audio source on.
Activate the analog output at the audio
source.
No audio connection to the audio sink (e.g.,
computer) available.
Check the connection of the audio cable
between the CPU Unit and the audio sink.
Check the audio configuration.
9.4 Add-on Module, Digital Audio
Source side (CPU module)
Sink side (CON module)
Fig. 49
Interface side add-on module digital audio - Failure indication
Diagnosis
Possible reason
Measure
CPU Unit:
LED
1
lights up
red.
No audio connection to the audio source
available.
Connect a digital audio source.
Check the connection of the audio cable
between the CPU Unit and the audio
source.
No signal available.
Switch the digital audio source on.
Activate the digital output at CPU/audio
source.
CON Unit:
LED
1
lights up red.
No audio connection to the audio sink (e.g.,
speakers) available.
Connect the digital audio sink.
Check the connection of the audio cable
between the CPU Unit and the audio
source.
No signal available.
Check signal at CPU Unit.
No signal:
CON Unit:
LED
1
lights up green.
CPU Unit
:
LED
1
is flashing.
Digital noise at the active audio source.
Check the audio format (see LED color at
the CPU Unit, see chapter 4.7.1,
page 33).
Check the mute setting.
Change the audio input.
1
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