Digital Clock Configuration - Lab.gruppen PLM series Operation Manual

12.6 Digital Clock Configuration

In order to provide a highly flexible and robust audio processing system, PLM Series devices are equipped
with a configurable clocking system. To fully take advantage of the flexibility the system needs to be config-
ured with respect to clock source and base rate.
The clocking system can either rely on its internal clock, or it can sync to an external incoming clock source
via the PLMs AES digital input. There are two options for clock source configuration: manual configuration
or automatic detection.
▸ Manual configuration mode: The user can select either the internal or the external clock. The clock
remains fixed at the configured source.
▸ Automatic detection mode: The PLM automatically chooses the available clock with the highest priority
according to the following priorities:
1. The incoming external clock via the AES digital input
2. The internal clock.
The PLM always monitors the AES digital input and will seamlessly switch the clock source back and forth
depending on the availability of an AES signal.
There are two options for the incoming clock base rate configuration: 44.1 and 48 kHz The PLM must be
configured to one of the base rates and it will then only lock to incoming AES signals that are based on that
rate. If failing to lock to the incoming clock the clock status will be reported as slipping and the audio signal
will be distorted.
▸ 44.1 kHz: Includes sample rates equal to the base as well as the multiples 88.2 and 176.4 kHz.
▸
48 kHz: Includes sample rates equal to the base as well as the multiples 96 and 192 kHz.
The available options for configuring the PLM Series digital clock are as follows:
3. Auto 44 detection
4. Auto 48 detection
5. Manual 44 config
a. External AES clock
b. Internal clock
6. Manual 48 config
a. External AES clock
b. Internal clock
12. Application Guide
PLM Series Operation Manual rev 1.1.3
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