Functional Description - Symmetricom TSG-3800 Series User Manual

Output Modules
RS-422 Clock Output Module
Table 7-27 describes the RS-422 Clock Output module front panel status indicators
(LEDs).
Table 7-27. RS-422 Clock Output Module Status Indicators
Indicator
POWER Green
INPUT Amber
FAULT A
INPUT Amber
FAULT B
OUTPUT Red
FAULT

Functional Description

Refer to Figure 7-12
reference input signals (A and B) from separate Frame Generator modules. The
module selects one of these signals (normally A) and applies it to two drivers. Each
driver supplies 10 square wave outputs in an RS-422 format.
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.
242 TSG-3800 User's Guide
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Color
On = The module is receiving power.
On = No reference signal applied to input A.
On = No reference signal applied to input B.
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