Diagnostics / Indicators - QSC DCM series User Manual

setting monitors the speakers on the backwall.
Other installations might require speaker sets where some speakers are along the theater side
walls where other speakers are under a balcony overhang. By connecting these speakers as "zo-
nes", the sound levels will be much easier to balance.
Any of these amplifier outputs can be verified by selecting them to be routed to the DCM monitor
speaker.
The DCM also has 4 Subwoofer outputs. Each of these outputs can be individually selected for
monitoring on the front panel speaker.
The front panel monitoring logic allows combining amplifier channels to verify individual signals or
combinations of signals.
NOTE: All combining of the individual frequency outputs (2-way or 3-way) is done automatically,
so all front panel monitoring is of a full frequency signal.

3. Diagnostics / Indicators

The Diagnostics / Indicator section includes an extremely simple method of verifying proper sys-
tem operation and performing basic troubleshooting.
The Power indicator indicates whether the DCM unit is on or off.
The Input Clip indicator is helpful in verifying that the cinema format processor is not over-driving
the DCM input circuitry.
The Load Fault indicator is a unique and powerful feature which verifies that signal inputs into
the DCM actually make it through the DCM, the DataPort cables, and the amplifier unit all the
way to the speakers, and that the speaker connections are not electrically shorted or open. All of
these measurements are being performed constantly (without user action) on ALL output channels
and any unusual readings will light the Load Fault LED. If the Load Fault LED is lit, pressing the
Diagnostics button (and holding it pressed) will cause the problem channels indicator LED to
light. This information will let you inspect the system cabling for that channel and troubleshoot
the problem.
There are two types of indication: If the PROC LED and AMP LED are on, there is no amplifier
detected at that DCM amplifier connector. If the AMP LED is on, the amplifier on at that output is
measuring a short or an open on its output terminals.
REMEMBER: If you configured the DCM Commander software to not have certain channels (for
example there is no SUB 3 or SUB 4), these channels WILL NOT indicate any faults.
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VERY IMPORTANT:
The Load Fault detection software within the DCM unit uses a complex
averaging algorithm which compares input signals to output signals and measures voltage and
current on all amplifier outputs. To sense real world conditions, these measurements must be
found to be "out of range" many times before the Load Fault condition is indicated on the DCM
front panel. So if you are simulating fault conditions, you MUST have a "real-world" signal level
through the device (full signal input), and the fault condition must exist for several minutes before
the front panel Load Fault LED will light. This extra fault verification time eliminates false
triggering which would be confusing to a user. In conclusion, Just shorting the output terminals
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