Crest Audio NEXSYS - VERSION 3.0, Руководство пользователя программного обеспечения

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Crest Audio Inc. NexSys v. 3.0
15. Load Monitoring
Optional NexSys Load Monitoring is a powerful diagnostic tool that provides a consistent
means to verify performance of the drive lines and speakers in the system. Load Monitoring
inserts a test signal into the amplifier and then measures load impedance & current to derive
an impedance versus frequency response curve.
Pro class systems have an oscillator within the Supervisors to generate the test signal. The
Load Monitor main frame that is positioned post amplifier will measure and report the load
impedance at various test frequencies. This data is represented in NexSys as a graphic
impedance versus frequency response chart.
CK family amplifiers perform the same tests entirely on-board the amplifier (with the
optional NC-SLM module).
Load Monitor tests can run automatically at periodic time intervals using the Event
Scheduler. For example, if your system is in a busy transportation station, an impedance
sweep of each speaker line can be set to take place every night at 2AM. If the Load Monitor
detects an impedance variance beyond the user defined tolerance, an alert will be sent to the
Event Log. Each test sweep is saved forming an impedance history for each amplifier chan-
nel - driver pairing.
Amplifier output and line impedance changes are most often caused by weakened or failed
speaker components or wiring. Whenever there is a major change in the impedance, thor-
ough testing may be necessary to determine where the fault resides within the speaker cir-
cuit.
15.1 Load Monitor Setup for CK family Amplifiers
CK family amplifiers incorporate the Load Monitor as an integral part of the amplifier so no
additional wiring or software configuration is necessary.
15.2 Load Monitor Setup for Pro Class Amplifiers
The Load Monitoring process is tied to an amplifier channel. For the Pro class additional
wiring and software configuration is required. You must connect Supervisor and Load
Monitor mainframes to the test amplifier and then enter their configuration into NexSys’
amplifier setup window. The data specifies the address of the Load Monitor mainframe and
the channel (daughter card) to which the amplifiers output is fed.
First, highlight the test amplifier in either the Plan Inventory or group window. Then click
the right mouse button to access its Setup window. The data you are required to enter will
include is the HUB address (if one is used) the Load Monitor address and the specific chan-
nel to be measured.
15.3 The Reference Curve
Once you have entered the configuration data for addressing you must establish the actual
test parameters. Make sure the test amplifier is highlighted and click the right mouse button
to access it’s Load Monitor window
Device | Load Monitor
A graph will appear which is the template that all Load Monitor test use. Prior to conduct-
ing an actual test you must first specify the tests parameters. These include frequency pass
Software Manual Page 15.1