Precise Time and Frequency ptf 1226, Руководство по эксплуатации и обслуживанию

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1.
ptf 1226 Auto Switch with Distribution - Technical Overview
The ptf 1226 is an extension on the prvious ptf 1226A, and adds additional inputs
capability, additional output capability, and enhanced monitoring and control. The
unit is configurable according to application requirements and can house up to 3
channel pairs of auto switch input, and up to 36 distribution outputs all housed in
one, 2U high rack mounting unit.
The input signals accommodate either a 13dbm RF sine wave (1volt RMS), a
TTL digital input (usually 1PPS), or IRIG B amplitude modulated time code. The
channel characteristics are factory configured before shipment.
Each Switching Channel selects the primary input and routes it to a distribution
module to provide the required number of outputs. Detection logic embedded in
an on-board CPLD on the auto switch modules determines if there is a fault
condition on the primary input and then, if so, automatically switches to the
backup input, provided the backup input is in a “healthy” condition.
In addition, the unit continuously monitors all switching channel inputs and
distribution outputs, and provides a summary fault indication (change over relay
contacts) if any one of the primary or backup inputs or any of the distribution
outputs is reporting a fault.
The Auto Switch normally outputs the primary channel input signals, and
automatically switches to the back-up channel based on health status of the
measured inputs
Output (to BNC)
Input A
Input B
Figure 1. Photograph of internal Auto Switch Module