Installation guide

VAR4 / VAR12 / VAR20 - Product Description
3.7.3 Contact Functions
3.7.3.1 Routing
Any contact may be configured to control Latent Routes, i.e. pre-programmed routes which are controlled by
a contact closure. Routes may be assigned as Non-latching or Latching. In the latter case, a separate
contact may be assigned as a matching ‘reset’ contact.
3.7.3.1.1 Latching Mode
Any contact may be configured to trigger a latched Latent Route. A momentary, or prolonged, activation of a
latching trigger initiates routing. A separate contact is required for latching inputs, to act as a ‘reset’ contact.
This method is normally used to trigger emergency DVAs from fire systems, although any input source may
be routed in this way. For Fire Alarm DVA messages, BS5839 Pt 8 recommends the use of latched triggers
with separate resets, so that the message will continue to run even if the trigger pair fails.
Each latching trigger can be configured to initiate routing of any DVA to any output. It is possible to initiate
simultaneous routing of multiple DVAs to multiple outputs with a single trigger. This is so that, for example,
Alert and Evacuate messages may be able to be broadcast to different zones for a single trigger. The DVA
or DVAs will play until a momentary assertion of the matching ‘reset’ line, unless the corresponding trigger is
still asserted, in which case the DVA will not be reset.
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It is possible to configure whether or not a particular route causes busy indications to be shown
on microphone consoles.
For example, a busy indication would not be desired if the Latent Route mechanism was to be
used for enabling a background music source.
If used as a DVA trigger, the contact is configurable for two modes: ‘DVA Full’ and ‘DVA Part’.
• DVA Full
In the ‘DVA Full’ mode, when the ‘reset’ is received, the DVA or DVAs will complete its full message
cycle and broadcast till the end of the DVA message before ending.
• DVA Part
In the ‘DVA Part’ mode, when the ‘reset’ is received, the DVA or DVAs will end immediately even if part
way through a DVA message broadcast.
DVAs can be assigned priorities as described in Section “3.4 Audio Input Priority and Override”. Once
triggered, DVAs may be overridden by any higher priority DVAs, or other inputs that are routed to the same
output.
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A group of route triggers may share a single reset, or each route trigger can have its own
dedicated reset. If multiple DVA routes have been triggered by consecutive triggers in a single
group, the activation of that group’s ‘reset’ line unlatches all the DVA routes associated with that
reset. However, if any of the triggers are still asserted, these DVAs will continue to play, while
the others will be reset.
Issue: 03 complete, approved
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