Axis Communications 210A - Manual (Page 25)

25 AXIS 210/210A/211/211A - Audio (AXIS 210A/211A only)
Full-duplex mode means you can transmit and receive audio (talk and listen) at the same
time, without having to use any of the controls. This is just like having a telephone
conversation. The only controls you may wish to use are the mute buttons to turn off the
sound, and the sliders, to adjust the input/output volume levels. This mode requires the
client PC to have a sound card with full-duplex audio support. If your available bandwidth
is 0.2 Mbit/s or less, using Half-duplex mode is recommended instead.
Half-duplex mode also transmits and receives audio in both directions, but only in one
direction at a time. This means that you must select when to receive or transmit audio with
the help of the push-to-talk button. To speak, press and hold the button (check that the
microphone is not muted). When finished speaking, release the button. You will now be
receiving audio from the other end of the connection.
Note that the push-to-talk button is configured from AMC, see AXIS Media Control, on
page 23. It is also possible to configure the push-to-talk button so that it toggles between
speaking and listening modes. Half-Duplex mode is best if you only have limited
bandwidth available.
When selecting Simplex - AXIS 210A/211A speaker only mode, the speaker connected to
the camera will play audio, but no audio will be transmitted from the camera to other web
clients. This could be used to e.g. provide spoken instructions to a person seen in the
camera. This mode requires you to use the push-to-talk button.
Simplex - AXIS 210A/211A microphone only mode transmits audio only from the AXIS
210A/211A to web clients. It will not receive audio from any other web clients. This can be
used in remote monitoring, web attractions etc., to provide live audio, as well as video, of a
monitored situation.
When using half-duplex, the Send the sound from the active client to all other clients
option transmits the audio signal from the client that is talking to all the other clients.
Audio Input
Audio from an external microphone or a line source can be connected to the Line/Mic in
jack of the AXIS 210A/211A. The audio source can be set to Internal Microphone,
External Microphone or Line. If you are using a microphone, the input sensitivity can be
set to High or Low. See Technical Specifications, on page 49 for the exact maximum
levels.
The Enable microphone power option provides DC power for an external microphone. If
using a small electret condenser microphone such as a clip-on mic or a PC microphone,
this option needs to be enabled.
To use a high impedance dynamic microphone, DC power should not be enabled. DC power
will not harm the microphone, but if you are uncertain, try switching it off and on. The
default value is DC power enabled. To use a professional microphone requiring 48V
phantom power, you need an external power supply and must use a balanced-unbalanced
converter (audio transformer) in between.