GAI-Tronics MI05-101 Merge / Isolate Cabinet with External Option - Manual (Page 8)

Pub. MI05-101iom.2
Model MI05-101 Merge/Isolate Cabinet Page: 8 of 24
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Fault Light Indicator
The red LED indicator on the Audio Switching PCBA illuminates if data communication is lost to any of
the master stations.
Alarm Mode Jumper
At the master I/O controller module, a jumper is pre-installed at the factory between terminals 15 and 16
at TB8. The following describes the modes of operation if the jumper is installed or removed:
Installed (manual alarm routing) –With the jumper installed, any alarm activation at the master or at
an external input will cause the AMI to become active, but the alarm audio will be broadcast only to the
master station(s). This feature allows the master station operator to direct the alarm audio to the zone(s)
affected by the alarm event.
Removed (automatic All-Zone alarm) –If the is jumper removed, any alarm activation at the master or
at an external input will cause the AMI to become active, and also automatically route the alarm audio to
all zones. The master operator can intervene and deselect zone(s) not affected by the alarm event.
Setting Jumpers and Adjustments
Line Balance Adjustment for Page Lines
A line balance adjustment is provided for each zone and the master stations. The line balance adjustment
is factory-set for optimum performance but may need adjustment in some situations. If the line balance
adjustment is set too low, the speaker volume will also be low. If the line balance adjustment is set too
high, the speaker audio will be distorted. To correct low or distorted audio, complete the following
adjustments.
Master Stations
Perform the following steps to properly adjust the line balance assembly:
1. Remove the page line conductors from terminals 7 and 8 on the Termination PCBA. See Figure 2
for terminal block location for the master station.
2. Place an ohmmeter across terminals 7 and 8 on the Termination PCBA.
N OTE : The optimum page line balance is 33 ohms.
3. Adjust potentiometer R15 on the Audio Switching PCBA to achieve 33 ohms on the ohmmeter.
Field Stations
Perform the following steps to properly adjust the line balance assembly for all zones:
1. Remove the zone page line conductors from terminals 1 and 2 on the Termination PCBA. See Figure
2 for the terminal block location for each zone.
2. Place an ohmmeter across terminals 1 and 2 on the Termination PCBA.
N OTE : The optimum page line balance is 33 ohms.