Ampcontrol VAA, User Manual

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VOICECOM USER MANUAL ISSUE 4
-42-
Verifying the Pre-start Alarm Request Input
For troubleshoot purposes, the PSR1 and PSR2 digital input states can be verified by looking at the Line Status page
for the desired line or the Digital Inputs page. Figure 30 below shows that the PSR1 input, the pre-start request input
for LINE 1, is being asserted, as indicated by the
o-o
graphic.
VAA Pre-start Alarm Sounding and Confirmation
1. All connected VAAs will receive the pre-start command and necessary parameters from the VCA.
2. The alarm tones are generated locally by each VAA, not by VCA. The tone sounded depends on the pre-start
tone set for that line at the VCA.
3. While the VAA sounds the alarm, its display will alternate between showing the text
PS ----
and the current
being drawn from the battery. The “
----
” indicate that the alarm has not yet been confirmed for that VAA.
4. During this time, the VAA measures the current being drawn from the battery and compares this value with the
current threshold level it is receiving from the VCA. A VAA will typically draw anywhere between 140mA to
180mA with two speakers connected. If one speaker fails, the current drawn will be approximately half the two
speaker value. If both speakers fail, the current will only be a few mA.
a. If the current being drawn from the battery exceeds the current threshold level then the pre-start
alarm has successfully sounded at the VAA. The VAA display will alternate between showing the
text
PS PASS
and the battery current. The VAA will send this confirmation back to the VCA.
b. If the current being drawn from the battery is less than the current threshold level then the pre-start
alarm has failed at the VAA. The VAA may have still sounded the alarm. The VAA display will
alternate between showing the text
PS ----
and the battery current. The VAA will not send
confirmation back to the VCA.
5. The current shown on the VAA display during a pre-start will help to understand why a VAA is not confirming a
pre-start alarm.
NOTE: Each pre-start alarm tone, while sounding, may draw a different amount of current. Some testing will have to
be conducted to find a suitable current threshold level.
5 D-In PS2o/o PS1o-o
1o/o 2o/o 3o/o 4o/o
5o/o 6o/o 7o/o 8o/o
9o/o Ao/o Bo/o Co/o
PSR1 digital
input state
2 Line 1 [12] VAA’s
PSW RQ o-o OPo/o
█ █ █ █ █ █ █ █ █ █
-----
----
█
----- -----
█
Figure 30 - Verifying the PSR Input