Functional Description - Symmetricom TSG-3800 Series User Manual

Output Modules
Output Fault Analyzer

Functional Description

The functional block diagram of the Output Fault Analyzer is shown in Figure 7-28.
The 20 output signal (Ring/Tip) pairs enter the Analyzer on the card edge connector.
Each signal is transformer-coupled; any DC component is removed by a blocking
capacitor. The signal then goes to a diode detector and R/C filter to a comparator
circuit, where it is converted to a TTL-level signal. When this TTL signal is Low, a
latching flip-flop is Set, which drives a red LED indicating a Fault condition. The
latching flip-flop is cleared when the user presses the Reset button, setting the
LEDs to green. Any output signal that drops below the fault threshold causes the
LED to turn red again.
When the Analyzer is initially installed, all LEDs are red until the Reset button is
pushed; they then indicate the current status of the output signals.
Power for the logic circuits and the LEDs is provided by a DC/DC converter, which
converts the fused, summed, and filtered –48 vDC input power from the TSG-3800
to 5 vDC. When power is present, the green Power LED is lit.
The input termination of the Analyzer is high impedance to minimize loading of the
output signals being tested.
12778474-002-2 Revision F – March 2004 TSG-3800 User's Guide 289
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com