Grass Valley AMX-3981 2014 - Manual (Page 68)

GUIDE TO INSTALLATION AND OPERATION
62 | AMX-3981
Audio Conditions – type a Presence/Type string into the data box for each of the presets that you wish to recall
automatically. Priority will be given to the first condition (USER 1). For example, if you want to do something when 5.1
audio is detected and something else when it is not detected, define the audio condition for 5.1 as the first condition.
The string represents the input configuration that will trigger the preset.
• A useful way to determine the appropriate entry is to set up the inputs to the configuration of interest, and then
copy the string that appears in the Current Presence/Type String data box into the User Preset data box. Note
that unused channels should be set to ‘X’ (don’t care) rather than 0 (absent).
While you are typing, note that:
• Only the characters that are significant can be typed; other keystrokes have no effect
• Characters are not case sensitive, although they appear as capitals in the databox.
• Click and drag to select one or more characters to type
• If you stop typing before filling all the selected character spaces, all remaining spaces will be filled with X (i.e.
don’t care) once you move the focus away from the box.
• The AMX-3981 will automatically detect conflicts, i.e. audio conditions that could call both presets
simultaneously. This could arise because of Don’t Care situations, or because the same string was accidentally
entered in both preset boxes. The most recently entered string will appear in red and will not be active. In case
of conflicts, the User Preset 1 condition will have priority.
Delay – set the delay between the detection of the condition that triggers the loading of a preset, and the actual
execution of the preset.
• The range in the scroll box is from 0 msec up to 500 msec, continuously variable.
• For AMX-3981, the default value is 33 msec, but the optimum value really depends on the application.
The Delay parameter is used to delay the loading of a User Preset into the card’s hardware. The delay range will be
from the fastest audio condition detection time to the longest processing delay of the card.
To begin, note that the Audio Type detector and the Audio Presence detector are both located at the input to the card:
The idea is to calculate the time delay as the audio passes through the AMX-3981 between the time at which the
audio condition is detected, and the time when the audio arrives at the location where the changes in processing need
Figure 5.59 Relative position of audio presence and type detectors