5.1. Identifying a Device Remotely
When several 12Mics are connected to the same network, each device has its own remote control. To
quickly reveal which device is currently being controlled, the web remote and any AVDECC controller can
send an
Identify
command. This triggers an animation of the front panel level meters of the
corresponding device.
To start device identification with the web remote:
1. Open an 12Mic web remote in a browser (see
Section 2.3, “Controlling the device”
2. Press the
identify
icon. The front panel level meters of the controlled device will show an
animation.
Depending on the controller, the animation may persist infinitely or stop after a short
period of time.
5.2. Changing the Device Name
A custom name can be assigned to the device. It is used to identify the AVB entity with AVDECC
controllers. It also allows the access to the web remote without using the IP address on Apple macOS™
computers.
The device name is stored to and recalled from
presets
. Loading a preset can therefore
change the device name. It is not affected by firmware updates.
Changing the device name is only possible via web remote or AVDECC controller.
5.3. AVB Stream Size and Format
In an AVB network, a
stream
describes a connection between a
talker
and one or more
listeners
. It
consists of a fixed number of audio channels at a fixed sample rate. The
stream port
of the talker and the
listener must be configured to have the same amount of channels and stream format. Once a stream is
connected, each AVB switch along its way ensures that the audio channels can pass in time, with a
higher priority than other network traffic.
For audio transport, AVB audio endpoints support the AM824 Stream Format or the more efficient AVTP
Audio Format (AAF). Additionally, they may support the Clock Reference Format (CRF), which contains
only clock information, but no audio.
The 12Mic supports a total of
eight incoming streams
and
eight outgoing streams
. Each stream port
can be individually configured to contain
1-8, 12 or 16 channels
in AM824 or AAF format. Additionally, a
stream port may be configured for 0 channel CRF streams.
5.4. AVB Network Latency
All devices in an AVB network share the same time. This allows the sending device (
talker
) to specify the
precise point of time when its audio samples should be played out at the receiver side (
listener
). This is
achieved by adding an
offset
to the current time and sending the resulting timestamp with each sample
transmitted. The timestamp is called "presentation time" and has nanosecond precision. For comparison,
a single sample at 48 kHz has a duration of over 20800 ns.
The receiver compares the incoming presentation time of each sample to the current time and buffers
the sample until the presentation time is has come.
RME 12Mic User’s Guide
21
| 5.1. Identifying a Device Remotely
