Functional Description; Kbit Clock Output Module Status Indicators - Symmetricom TSG-3800 Series User Manual

Output Modules
56 kBit Clock Output Module
Table 7-39 describes the 56 kBit Clock Output Module front panel status indicators
(LEDs).
Table 7-39. 56 kBit Clock Output Module Status Indicators
Indicator
POWER
INPUT FAULT A
INPUT FAULT B
OUTPUT FAULT

Functional Description

Refer to Figure 7-18
64 kHz Composite Clock reference inputs (A and B) from separate Frame
Generator modules. Each signal enters a Byte Alignment Extractor which generates
an 8 kHz output. Internal 56 kHz signals are phase locked to the 8 kHz signals.
A multiplexer receives both phase locked 56 kHz signals. The module selects and
drives one of them (normally A). This signal couples to the output ports through
transformers.
If reference signal A fails, the module detects its loss and switches to reference
signal B. The processor can also switch references.
The module checks the outputs to confirm signal presence. Should an output fail,
the front panel OUTPUT FAULT indicator lights.
Power A and B on the main shelf provide power to the module. These redundant
sources of –48 vDC are diode-coupled and fused, allowing the module to draw
power from either source. The internal fuse labeled F1 protects the circuitry from
excessive current. The DC-to-DC Converter changes the negative voltage into +5
vDC; the green POWER indicator on the front panel is lit when either power source
is available to the module. The POWER indicator turns off when power is lost, for
example if the fuse on the module opens, if both –48 vDC power inputs are lost, or if
the converter fails.
260 TSG-3800 User's Guide
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Color
Green On = The module is receiving power.
Amber On = No reference signal applied to input A.
Amber On = No reference signal applied to input B.
Red On = Output failure on one or more channel.
for the following functional discussion. The module accepts two
Description
12778474-002-2 Revision F – March 2004