Figure 5-3. Network Timed Clock Source - ADTRAN TSU LT User Manual

TSU LT User Manual
TSU LT Clock Sources
The TSU LT is operable from various clock sources, permitting it to perform properly in many
different applications. The network interface clocking options are set by using the Network
Configuration menu options. Three clock source options are available:
• Network timing
• DTE timing
• Internal timing
The clocking option selected always designates the clock source for transmission.
Clocking necessary for receiving data is always recovered from incoming data.
Network Timing
The network is the source of timing. The received data clocking is looped back to the network where
it is used to determine the transmission timing. This option is also referred to as looped timed as the
transmission clock is derived from the received clock. See Figure 5-3.
DTE Timing
The DTE is the source of timing. The TSU LT uses the incoming DTE clock to determine the
transmission timing. This is typically used in applications such as limited distance line drivers,
where it is necessary to have the DTE as the primary clock source. See Figure 5-4 on page 46.
61202060L4-1

Figure 5-3. Network Timed Clock Source

© 2002 ADTRAN, Inc.
Chapter 5. Configuration Menu
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