Ampcontrol VAA, Руководство пользователя

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VOICECOM USER MANUAL ISSUE 4
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Volume and Microphone Gain
The volume and microphone gain are combined into one setting, for example “L3” where L is the gain level and 3 is
the volume level. The volume setting controls the VAA unit’s output volume. The volume can be set to a value from 0
to 3 where 3 is the maximum volume. This applies to voice communication only. Pre-start alarms always sound at a
fixed volume. The VAA unit’s microphone gain is set in conjunction with the volume setting. The gain can be set to
“L” for low or “H” for high. The low gain setting would be appropriate for an environment with a high level of
background noise. The low setting necessitates that the operator speaks close to the VAA and raise his voice. The
high gain is suitable for most other low noise environments. Some simple tests will help to find an appropriate gain
level.
Battery Charging Current
The battery charging current can be set to a value between 5mA and 40mA. As soon as current is drawn from a VAA
battery due to a pre-start alarm, for example, the battery will want to immediately recoup any lost charge. The
battery will take as much current as it has been set to take. Because the current available from the intrinsically safe
power supply is limited, some planning is required when choosing a battery charging current for a particular VAA unit.
If the charging currents are set too high, the VAAs closest to the power supply will take all the current they can
leaving little current for the VAAs furthest away from the power supply. These VAAs may never charge fully. An
example will help to illustrate this.
Example: There are 31 VAAs connected to LINE 1 and a 14VDC 1A I.S. power supply is being used. The battery
charging current of all the VAAs has been set to 40mA. Assuming all the batteries are fully charged, a pre-start alarm
is sounded. As soon as the pre-start alarm stops, all VAAs will try to draw 40mA from the line power supply. The first
20 so VAAs may be able to draw at or near their set charging current, leaving little current left for the last 10 VAAs.
Again, some testing will need to be conducted in order to find the optimum charging currents. Trending VAA battery
voltages and currents over a period of time will help with this. However, 20mA would be a good starting point.
Setting VAA parameters:
1. Go to the VAA Status page of the VAA you wish to program. Press to enter the VAA Set Up page.
Figure 21 shows the VAA Status page for the VAA at address 1.
2. Press the

keys to scroll between the VAA settings: CHARGE CURRENT – MIC GAIN/VOLUME –
THRESHOLD.
To change a setting, press the key and then the press the

key to decrease or increase the value.
3. Press the key to save the new value.
ENTER
ENTER
ENTER
2 L1 VAA # 1 Set Up
Funct. < ent > [esc]
Bat Chrg.Cur.:[40mA] 2 L1 VAA # 1 Set Up
Funct. < ent > [esc]
VAA Volume[3], Mic[L] 2 L1 VAA # 1 Set Up
Funct. < ent > [esc]
Audio Threshold [2]
Figure 21 - Entering VAA Setup pages
2 L1 VAA # 1 Set Up
Funct. < ent > [esc]
Bat Chrg.Cur.:[40mA]
2 L1 VAA # 1 0 100
Vline:12.0V Thr:[ 2]
Vbatt: 6.6V Vol:[L3]
Ibat: 11mA Ich:[20]
ENTER
VAA Status Page
VAA Setup Page