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Chapter 6 - Measuring Mode UMS (Upstream-Monitoring-System)
AMA 310/UMS V21.0
settings (see Chapter 8.1.5.3 - TILT Measurement), can be seen. The following two figures show
both display screens as an example.
Figure 6-13 LC display during TILT measurement by a field instrument
Figure 6-14 Graphics display during TILT measurement by a field instrument
6.6.7
Report Generation by a Field Instrument
The field instruments can generate an automated report (protocol) as specified by the headend. For
the report, all measurements which the measurement system is able to perform are carried out one
after the other. This means: a MER/BER measurement on up to four test carriers, a frequency
sweep for exact frequency response analysis of the overall return channel frequency range as well
as (independent of the UMS system!) a measurement of forward channels by the field instrument.
For the displays at the headend, this simply means that the above described displays for BER
measurement, frequency sweep, ranging processes and telemetry communication alternate.
6.7
Timeout
If a field instrument does not actively terminate an exclusive measurement (e.g. sweeping, BER
measurement) (e.g. because the battery of the field instrument is empty or a technician forgets to
terminate the measurement), the exclusive measurement of the headend is terminated according to
a fixed timeout of about 10 minutes.
In this case, a relevant message is shown on the field instrument ("Measurement stopped from
Headend").
This ensures that a forgotten or defect field instrument does not block the UMS system too long
and also other field technicians can perform their active measurements.
The counter performing the timeout is reset whenever the headend receives new instructions from
the field instrument by telemetry commands.