AS
Mxxxx Series User’s Manual
Asia Pacific | EMEA | Americas
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Next Scheduled Test:
The next scheduled date/time that the Automatic Test Schedule will be performed.
Parameters Used:
The known RF site parameters that are used in performing the System Isolation Tests. These parameters are collated from data
fields on the various ASM GUI configuration screens,
Test Results:
The displayed results of the System Isolation Tests. These are as follows;
Tx-Rx Antenna Isolation Iso (Ant Iso):
The first line of the Test Results table displays the calculated Tx-Rx Antenna Isolation value, and is measured using the ASM
’s
internal signal generator operating on the displayed Rx Frequency. The value measured and displayed represents the minimum
isolation value between any of the monitored Tx and Rx antennas. In multiple Tx antenna systems, this value represents the
sum of all Tx-Rx isolations seen in parallel, and in multiple Tx antenna installations this value usually represents the worse-case
Tx-Rx antenna isolation path at the site.
This test’s measured Rx Level is provided in the right hand column for information.
Note:
The isolation that can exist between antennas, particularly in dual/triple/quad stacked models, can vary significantly by
frequency, and may be higher than the ‘typical’ or ‘minimum’ value stated in the antennas’ published specifications.
Therefore, it is recommended to measure the achieved antenna isolation on a site during the commissioning of the site
(or the initial installation of the ASM), and to apply alarm values in the ASM configuration screen that are appropriately
set either side of the emasured antenna isolation at the proposed test frequency. The
Test Now
function may be
useable to perform this initial measurement if the achieved isolation value is within the measurement range of the ASM.
Rx System Performance (Rx System):
The next lines of the Test Results table display the calculated Rx System performance values, and is measured using the
ASM
’s internal signal generator operating on the programmed Rx Frequencies. Typically, nominated Rx frequencies at the
bottom, middle and top of the Receiver System preselector (or TTA) passband will suffice in providing an overall Rx System
Performance indication. Additional frequencies may be configured for this test if more thorough results are desired.
The Antenna Isolation value used for all Rx frequencies in this test is the above Tx-Rx Antenna Isolation value. The values
calculated represent the Rx Subsystem Gain/Loss value, and the displayed values should align similarly with the Rx Subsystem
Gain/Loss value displayed in the Parameters Used table. In the example shown, the preselector passband is 400-405MHz.
The preselector passband response roll-off can be seen in the frequency measurements either side of this passband. This
test’s measured Rx Levels (Measured) are provided for information.
These Rx System Performance measurements show the R
x system’s
gain and selectivity response. Additional frequencies could be configured
into this test to show the selectivity response values further outside the
passband if desired.
Tx Rejection (Tx Rejection):
The next lines of the Test Results table display the calculated receiver
subsystem’s Tx Rejection performance values, and is measured using the
monitored Transmitter’s outputs on the displayed Tx Frequencies.
Typically, nominated Tx frequencies at the bottom and top of the Transmitter frequencies monitored on the site (or multiple
bottom and top frequencies if multiple Tx sub-bands are ASM-monitored Tx combiners) will suffice in providing an overall Tx
Rejection performance indication. Additional frequencies may be configured for this test if more thorough results are desired.
The Antenna Isolation value used for all Tx frequencies in this test is a calibrated value measured for each Tx Antenna and
recorded in the
Configuration
– Isolation Tests
GUI page. The values calculated represent the overall rejection of the Tx
carriers, as seen at the Rx Subsystem, and include all Tx combiner, Tx Feeder, Tx-Rx Antenna Isolation, Receiver (or TTA)
Preselector selectivity, and Rx Subsystem Gain/Loss components. This test’s calculated Receiver (or TTA) Preselector Tx
carrier frequency rejection (Rx System) and the measured level of the Tx frequencies at the ASM Rx port (Measured) are
provided for information.
Measured:
The Rx RSSI value measured by the ASM during this test.
