Filter
Top Products
LBI-39128 OPERATION
28
SWR Upper Limit
This parameter is used by the PMU as the upper alarm
limit for each antenna’s SWR. Its purpose is to detect when
the antenna or coax to the antenna is damaged. The
recommended value for this limit is 2.0, which is equivalent
to about 11% reflected power.
This parameter is not programmed into the Site
Controller computer’s Personality PROMs and is therefore
not re-configurable through a System Manager. The value of
this parameter is only contained in the PMU.
A factory default value (2.0) for this parameter has been
programmed into the PMU. This factory default is used to
configure the PMU’s Active Configuration any time the
PMU is Initialized. The value of this parameter may be re-
configured with an RS232 CRT terminal connected to the
PMU. This re-configuration will last until you deliberately
initialize the PMU. This re-configuration permits a different
upper alarm limit for each antenna’s SWR.
Antenna Mapping
Antenna Mapping is described under the PMU
Programming heading in the Installation section.
ALARM LIMIT RE-CONFIGURATION
Alarm Limits As Installed
As installed per the Installation section, the alarm limits
are as follows:
• Transmitter Upper Power Limit = 125.0 watts
• Transmitter Lower Power Limit = Determined by
the Site Controller computer’s Personality PROMs
or the re-configured value with the System
Manager.
• Antenna Upper Power Limit = 999.9 watts
• Antenna Lower Power Limit = 0.0 watts
• Antenna Upper SWR Limit = 2.00
These alarm limits may be changed in the PMU’s
Active Configuration with a terminal connected to the PMU.
See the PMU Programming heading in the Installation
section to set up the terminal and obtain programming
access.
Transmitter Power Alarm Limits
The upper and lower alarm limits for each transmitter’s
output power may be re-configured as follows:
1. With the Operational Select Menu (main menu) shown
on the terminal, type 4 (for item #4 - Setup) and press
the Enter key.
2. With the Setup Selection Menu shown on the terminal,
type 4 (for item #4 - Analog Input Channel) and press
the Enter key.
3. At the “Enter Channel Number” prompt, type the
channel number of the transmitter and press the Enter
key. The Analog Input Channel screen for that
transmitter channel should then appear on the terminal.
4. Type 6 (for item #6 - Lower Alarm Limit) and press the
Enter key.
5. At the “Enter New Data” prompt, type the new value
and press the Enter key. The screen should then be
updated to show the new value. (This is a temporary
configuration.)
6. Type 7 (for item #7 - Upper Alarm Limit) and press the
Enter key.
7. At the “Enter New Data” prompt, type the new value
and press the Enter key. The screen should then be
updated to show the new value.
8. Type E (to End programming this channel) and press
the Enter key. The Setup Selection Menu should then
appear on the terminal.
This completes the re-configuration of the Upper and
Lower Alarm Limit parameters for the selected transmitter
channel number. If this parameter needs to be changed for
another transmitter, repeat steps 2 through 8 for that
transmitter. (Remember that the lower alarm limits you re-
configure here are just temporary. These limits will be re-
configured to the single value of this parameter in the Site
Controller computer’s Active Configuration each time the
Site Controller computer sends the EDACS Configuration
Setup to the PMU.)
Antenna Power Alarm Limits
The upper and lower alarm limits for the antenna’s
input power may be re-configured as follows:
1. With the Setup Selection Menu shown on the terminal,
type 4 (for item #4 - Analog Input Channel) and press
the Enter key.