IO Triggered

If enabled, the AVC value is controlled via the specified logic control input configured at the 'digInput' field.

If the input is low, the AVC value rises to the maximal attenuation factor.

If the input is high, the AVC value is 0 dB (no attenuation).

The meaning and behavior of this flag is changed when the 'Skip Calls' flag is active.

'Skip Calls'

It is used to freeze the AVC value during a priority call. If a call is pending, the latest AVC value is used until the call is over. After that, the AVC value calculation will continue.

'Skip use IO'

This flag is visible if the 'Skip Calls' function is active. The 'Skip Calls' flag freezes the AVC value during an active call. When the 'Skip use IO' is enabled, the AVC value also freezes in case of an active logic control input. Set the used logic control input at the “digInput” field.

'IO Triggered'

This flag is visible when the 'Skip Calls' function is inactive. It permanently disables the AVC value calculation. The AVC value changes depending on a logic control input of the local station. A logic control input can be selected in the 'digInput' field.


Set this value to a local analog audio output. This analog audio output signal is used for calculation of the AVC algorithm.


AVC takes effect when the noise level at analog audio input 4 (IN4) is above this level.

'Max Attenuation (Max Att.)'

Maximum range of volume control for the AVC algorithm in dB.


The attack rate of a signal in dB/s. A larger value means faster volume up when the noise level increases.


The release rate of a signal in dB/s. A larger value means faster volume down when the noise level decreases.

'Averaging Time'

Defines the measurement cycle time. A larger number means more stable AVC algorithm. However, for a long duration, the system will need more time to react on noise level changes.

'Feedback Factor'

This value is used for signal feedback of the configured analog audio output. A large feedback factor means that most of the level of the analog audio output is subtracted from the feedback analog audio input level. Therefore, it is quite noisy.

'Show RMS'

Level meter Input 1 and 2 display measured RMS values to observe the AVC calculation behavior.